Purpose

The Loewenstein Occupational Therapy Cognitive Assessment (LOTCA) battery was developed as a measure of basic cognitive skills and visual perception in older adults with neurological impairment. The LOTCA provides an in-depth assessment of basic cognitive abilities and can also be used in treatment planning and review of progress over time.

In-Depth Review

Purpose of the measure

The Loewenstein Occupational Therapy Cognitive Assessment (LOTCA) is a cognitive battery that measures basic cognitive skills required for everyday function including orientation, visual perceptual and psychomotor abilities, problem-solving"Goal-directed cognitive activity that arises in situations for which no response is immediately apparent or available" (Luria, 1966; as cited in (Rath et al., 2004))
skills and thinking operations. Development of the battery was based on information from clinical experience and neuropsychological and developmental theories. The LOTCA is typically used in the initial phase of patient assessment but can also be used to establish therapeutic goals and to review cognitive status over time (Annes, Katz & Cermak, 1996; Zwecker et al., 2002).

Available versions

The original LOTCA was developed by Itzkovich, Averbuch, Elazar and Katz for use with individuals below the age of 70 years with neurological dysfunction and consisted of a total of 20 items within 4 areas: Orientation (2 items); Perception (6 items); Visuomotor Organization (7 items); and Thinking Operations (5 items).

The LOTCA-II was modified by separating the Perceptual area into three separate areas (Visual Perception, Spatial Perception and Motor Praxis), revising items and including an additional Thinking Operations subtest. The LOTCA-II consists of a total of 26 subtests within 6 areas: Orientation (2 items); Visual Perception (4 items); Spatial Perception (3 items); Motor Praxis (3 items); Visuomotor Organization (7 items); and Thinking Operations (7 items).

The LOTCA-II includes multi-choice questions in the Orientation area to accommodate language difficulties. The manual has been updated to provide more accurate assessment and administration guidelines (Su, Lin, Chen-Sea & Yang, 2007).

Features of the measure

Description of Tasks:

The original LOTCA contains 20 subtests in 4 areas. The LOTCA-II contains 26 subtests in 6 areas:

• Orientation (2 subtests): Assesses the individual’s orientation to place and time.
• Visual Perception (4 subtests): Assesses the individual’s ability to identify pictures of everyday objects, objects photographed from unusual angles, distinguish between overlapping figures, and recognize spatial relations between objects.
• Spatial Perception (3 subtests): Assesses the individual’s ability to differentiate between right and left to determine spatial relationships between objects and self.
• Motor Praxis (3 subtests): Asesses the individual’s ability to imitate motor actions, use objects and perform symbolic actions.
• Visuomotor Organization (7 subtests): Assesses the individual’s ability to copy geometric figures, reproduce a 2D model, copy a coloured block design and a plain block design, reproduce a puzzle and complete a pegboard task, and draw a clock.
• Thinking Operations (7 subtests): Assesses the individual’s ability to complete tasks including sorting, categorization, and picture and geometric sequences (Annes et al., 1996).

Scoring and Score Interpretation:

Most subtests of the LOTCA are scored from 1 to 4, where:

• 1 = Patient fails to perform the task
• 2 = Patient is able to perform part of the task
• 3 = Patient is able to perform most of the task
• 4 = Patient demonstrates good performance of the task

However, three Thinking Operations subtests (Categorisation, Risk Object Classification – ROC – Unstructured, ROC Structured subtests) are scored on a scale from 1 to 5 (Josman, Abdallah & Engel-Yegar, 2010; Zwecker et al., 2002).

Most subtests of the LOTCA-II are also scored from 1 to 4 using the scale above. However, Orientation subtests are scored on a scale from 1 to 8 and three Thinking Operations subtests (Categorization, ROC Unstructured, ROC Structured) are scored on a scale from 1 to 5. Accordingly, the overall LOTCA-II score ranges from 26 to 115 points. Task completion through trial-and-error is penalized in three subtests. Performance elements such as the number of prompts provided to the individual to assist him/her in completing the task, the individual’s attention/concentration and length of time taken to complete the assessment are also recorded.

Results are provided as a profile for each subtest, where higher scores indicate less cognitive impairment (Su et al., 2000). While summation of subtest scores is accepted, the authors warn that analysis of a total score impacts on the ability to identify the individual’s aptitude for each cognitive area (Katz, Itzkovich & Averbuch, 2002).

LOTCA scores were normed on an Israeli population of adults aged 20 – 70 years (Annes et al., 1996), and have since been deemed suitable for use with the US population (Annes et al., 1996; Cermak, Katz, McGuire, Greenbaum, Peralta & Maser-Flanagan, 1995; Katz et al., 1997). Age-related change in scores is not accounted for, as score norms are provided for one group of all individuals aged 20 – 70 years.

Time:

The LOTCA and LOTCA-II take approximately 45 minutes to administer, with a reported range from 30 to 90 minutes (Annes et al., 1996; Zwecker et al., 2002).

Equipment:

The LOTCA kit contains testing materials (card decks, coloured blocks, pegboard set and other materials) and a manual that includes definitions of the cognitive domains assessed, instructions for administration and specific scoring guidelines.

Alternative forms of the Loewenstein Occupational Therapy Cognitive Assessment (LOTCA)

The LOTCA Geriatric version (LOTCA-G) is a modified version of the original LOTCA that was designed for use with individuals aged 70 – 91 years. The LOTCA-G was developed in response to difficulties that elderly patients experienced using the LOTCA (e.g. difficulty seeing and using small materials, and duration of assessment). Accordingly, it contains modifications to allow for age-related cognitive decline and sensorimotor difficulties including larger materials to compensate for visual and motor deficits, less visual detail, shorter subtests, multiple-choice questions, and additional memory tests not included in the original LOTCA (Cooke et al., 2006a, b; Bar-Haim Erez & Katz, 2003).

The LOTCA-G includes 23 subtests in 7 cognitive areas:

• Orientation (2 subtests): Orientation to place; and orientation to time
• Visual Perception (4 subtests): Object identification; shape identification; overlapping figures; and object consistency
• Spatial Perception (3 subtests): On self; on examiner; and self and surroundings
• Praxis (3 subtests): Motor imitation; utilization of objects; and symbolic actions
• Visuomotor Organization (6 subtests): Copy geometric forms; two-dimension model pegboard construction; block design (colour); reproducation of a puzzle; and drawing a clock
• Thinking Operations (2 subtests): Categorization; and pictorial sequencing"The coordination and proper ordering of the steps that comprise the task, requiring a proper allotment of attention to each step" (Lezak, 1989; as cited in (Baum, Morrison, Hahn & Edwards, 2007))
  
• Memory (3 subtests): Famous personality; personal possession; and everyday objects

The Orientation subtests are scored from 1 – 8 while all other subtests of the LOTCA-G are scored on an ordinal scale from 1 to 4, where 1 indicates severe deficit and 4 indicates average performance. The LOTCA-G takes approximately 30-45 minutes to administer (Bar-Haim Erez & Katz, 2003, Cermak, et al., 1995). It is available in English and Hebrew.

Client suitability

Can be used with:

• Patients following strokeAlso called a "brain attack" and happens when brain cells die because of inadequate blood flow. 20% of cases are a hemorrhage in the brain caused by a rupture or leakage from a blood vessel. 80% of cases are also know as a "schemic stroke", or the formation of a blood clot in a vessel supplying blood to the brain. (Bar-Haim Erez & Katz, 2003)
• Older individuals with dementia (Bar-Haim Erez & Katz, 2003)
• Individuals with traumatic brain injury (Annes et al., 1996)
• Individuals with CNS dysfunction (Annes et al., 1996)
• Individuals with intellectual disabilities (Jang, Chern & Lin, 2009)
• Individuals with mental illness (Jang et al., 2009; Josman & Katz, 2006)
• An adapted version has also been developed for use with children with learning difficulties (Josman et al., 2010)
• Patients with aphasiaAphasia is an acquired disorder caused by an injury to the brain and affects a person's ability to communicate. It is most often the result of stroke or head injury.
  An individual with aphasia may experience difficulty expressing themselves when speaking, difficulty understanding the speech of others, and difficulty reading and writing. Sadly, aphasia can mask a person's intelligence and ability to communicate feelings, thoughts and emotions. (The Aphasia Institute, Canada) – procedures for assessing the patient with aphasiaAphasia is an acquired disorder caused by an injury to the brain and affects a person's ability to communicate. It is most often the result of stroke or head injury.
  An individual with aphasia may experience difficulty expressing themselves when speaking, difficulty understanding the speech of others, and difficulty reading and writing. Sadly, aphasia can mask a person's intelligence and ability to communicate feelings, thoughts and emotions. (The Aphasia Institute, Canada) are included (Jang et al., 2009).

Should not be used in:

• An individual’s culture can affect the construct validityReflects the ability of an instrument to measure an abstract concept, or construct. For some attributes, no gold standard exists. In the absence of a gold standard , construct validation occurs, where theories about the attribute of interest are formed, and then the extent to which the measure under investigation provides results that are consistent with these theories are assessed.
  of the LOTCA when used with a pediatric population (Josman et al., 2010)

In what languages is the measure available?

• English
• Spanish
• Hebrew
• Chinese (Mandarin)
• Taiwanese
• Iranian

Summary

Psychometric Properties

Overview

A literature search was conducted to identify all relevant publications on the psychometric properties of the LOTCA. While this assessment can be used with various populations, this module addresses the psychometric properties of the measure specifically when used with patients with strokeAlso called a "brain attack" and happens when brain cells die because of inadequate blood flow. 20% of cases are a hemorrhage in the brain caused by a rupture or leakage from a blood vessel. 80% of cases are also know as a "schemic stroke", or the formation of a blood clot in a vessel supplying blood to the brain.. Eleven studies were identified.

Reliability

Internal ConsistencyA method of measuring reliability . Internal consistency reflects the extent to which items of a test measure various aspects of the same characteristic and nothing else. Internal consistency coefficients can take on values from 0 to 1. Higher values represent higher levels of internal consistency.:
Katz, Itzkovich and Averbuch (1989) examined the internal consistencyA method of measuring reliability . Internal consistency reflects the extent to which items of a test measure various aspects of the same characteristic and nothing else. Internal consistency coefficients can take on values from 0 to 1. Higher values represent higher levels of internal consistency. of the original LOTCA with patients with traumatic head injury (n=20), patients with strokeAlso called a "brain attack" and happens when brain cells die because of inadequate blood flow. 20% of cases are a hemorrhage in the brain caused by a rupture or leakage from a blood vessel. 80% of cases are also know as a "schemic stroke", or the formation of a blood clot in a vessel supplying blood to the brain. (n=28) and health adults (n=55), and reported excellent internal consistencyA method of measuring reliability . Internal consistency reflects the extent to which items of a test measure various aspects of the same characteristic and nothing else. Internal consistency coefficients can take on values from 0 to 1. Higher values represent higher levels of internal consistency. with alpha coefficients of 0.85, 0.87 and 0.95 for in the areas of Thinking Operations, Perception and Visuomotor Organization (respectively).

Test-retest:
No studies have reported on the test-retest reliabilityA way of estimating the reliability of a scale in which individuals are administered the same scale on two different occasions and then the two scores are assessed for consistency. This method of evaluating reliability is appropriate only if the phenomenon that the scale measures is known to be stable over the interval between assessments. If the phenomenon being measured fluctuates substantially over time, then the test-retest paradigm may significantly underestimate reliability. In using test-retest reliability, the investigator needs to take into account the possibility of practice effects, which can artificially inflate the estimate of reliability (National Multiple Sclerosis Society).
of the LOTCA when used with patients with strokeAlso called a "brain attack" and happens when brain cells die because of inadequate blood flow. 20% of cases are a hemorrhage in the brain caused by a rupture or leakage from a blood vessel. 80% of cases are also know as a "schemic stroke", or the formation of a blood clot in a vessel supplying blood to the brain..

Intra-rater:
No studies have examined the intra-rater reliabilityThis is a type of reliability assessment in which the same assessment is completed by the same rater on two or more occasions. These different ratings are then compared, generally by means of correlation. Since the same individual is completing both assessments, the rater's subsequent ratings are contaminated by knowledge of earlier ratings.
of the LOTCA.

Inter-rater:
Katz et al (1989) reported excellent inter-rater reliabilityA method of measuring reliability . Inter-rater reliability determines the extent to which two or more raters obtain the same result when using the same instrument to measure a concept.
for subtests of the LOTCA, with Spearman’s rank correlationThe extent to which two or more variables are associated with one another. A correlation can be positive (as one variable increases, the other also increases - for example height and weight typically represent a positive correlation) or negative (as one variable increases, the other decreases - for example as the cost of gasoline goes higher, the number of miles driven decreases. There are a wide variety of methods for measuring correlation including: intraclass correlation coefficients (ICC), the Pearson product-moment correlation coefficient, and the Spearman rank-order correlation.
coefficients ranging from 0.82 to 0.97.

Katz, Elazer and Itzkovich (1995) reported an agreement rate of 90% between 2 raters who used the LOTCA-G to assess 5 healthy subjects and 5 patients with strokeAlso called a "brain attack" and happens when brain cells die because of inadequate blood flow. 20% of cases are a hemorrhage in the brain caused by a rupture or leakage from a blood vessel. 80% of cases are also know as a "schemic stroke", or the formation of a blood clot in a vessel supplying blood to the brain..

Validity

Katz et al. (1995) reported that the LOTCA-G was tested on patients and healthy volunteers during its development.

Katz et al. (1995) reported that the LOTCA-G takes only 30-45 minutes (as compared to 30-90 minutes for the LOTCA), which verifies the LOTCA-G as a useful tool for use with an older population who demonstrate slower performance and sensorimotor difficulties.

Content:
Katz et al. (1989) conducted a factor analysis to determine the construct validityReflects the ability of an instrument to measure an abstract concept, or construct. For some attributes, no gold standard exists. In the absence of a gold standard , construct validation occurs, where theories about the attribute of interest are formed, and then the extent to which the measure under investigation provides results that are consistent with these theories are assessed.
of the original LOTCA, using two groups of patients with traumatic head injury or strokeAlso called a "brain attack" and happens when brain cells die because of inadequate blood flow. 20% of cases are a hemorrhage in the brain caused by a rupture or leakage from a blood vessel. 80% of cases are also know as a "schemic stroke", or the formation of a blood clot in a vessel supplying blood to the brain. (n=96), and health adults (n=55). In the patient group, Visuomotor Organisation loaded on Factor 1 with 44% variance, Perception loaded on Factor 2 with 12% variance, and Thinking Operations on Factor 3 with 10% variance. In contrast, in the control group, Perception loaded on Factor 1 with 33% variance, Thinking Operations on Factor 2 with 23% variance, and Visuomotor Organisation on Factor 3 with 6% variance. CorrelationThe extent to which two or more variables are associated with one another. A correlation can be positive (as one variable increases, the other also increases - for example height and weight typically represent a positive correlation) or negative (as one variable increases, the other decreases - for example as the cost of gasoline goes higher, the number of miles driven decreases. There are a wide variety of methods for measuring correlation including: intraclass correlation coefficients (ICC), the Pearson product-moment correlation coefficient, and the Spearman rank-order correlation.
coefficients within the Perception, Visuomotor Organisation and Thinking Operations subtests of the original LOTCA ranged from 0.40 to 0.80, indicating that subtests are not equivalent and the battery should be performed in full.

Su et al. (2000) examined the strength of correlations between LOTCA subtests on a sample of patients with strokeAlso called a "brain attack" and happens when brain cells die because of inadequate blood flow. 20% of cases are a hemorrhage in the brain caused by a rupture or leakage from a blood vessel. 80% of cases are also know as a "schemic stroke", or the formation of a blood clot in a vessel supplying blood to the brain. (n=44), using Pearson correlationThe extent to which two or more variables are associated with one another. A correlation can be positive (as one variable increases, the other also increases - for example height and weight typically represent a positive correlation) or negative (as one variable increases, the other decreases - for example as the cost of gasoline goes higher, the number of miles driven decreases. There are a wide variety of methods for measuring correlation including: intraclass correlation coefficients (ICC), the Pearson product-moment correlation coefficient, and the Spearman rank-order correlation.
coefficients. Large correlations were found between the Visuomotor Organisation and Thinking Operations areas (r=0.66, p<0.0001); moderate correlations were found between the Orientation and Perception areas (r=0.55, p<0.0001), Thinking Operations and Orientation (r=0.47, p<0.01) and Perception (0.32 p<0.05); and small correlations were found between Visuomotor Organisation and Orientation (r=0.23) and Perception (r=0.25).

Criterion:
Concurrent:
Bar-Haim Erez & Katz (2003) reported adequate correlations (from r=0.55 to r=0.38) between the LOTCA-G areas and the MMSE total scores in patients with dementia (n=30), using Spearman correlationThe extent to which two or more variables are associated with one another. A correlation can be positive (as one variable increases, the other also increases - for example height and weight typically represent a positive correlation) or negative (as one variable increases, the other decreases - for example as the cost of gasoline goes higher, the number of miles driven decreases. There are a wide variety of methods for measuring correlation including: intraclass correlation coefficients (ICC), the Pearson product-moment correlation coefficient, and the Spearman rank-order correlation.
analysis.

Cooke et al. (2006a) examined the concurrent validityTo validate a new measure, the results of the measure are compared to the results of the gold standard obtained at approximately the same point in time (concurrently), so they both reflect the same construct. This approach is useful in situations when a new or untested tool is potentially more efficient, easier to administer, more practical, or safer than another more established method and is being proposed as an alternative instrument. See also "gold standard."
of the OT-APST in patients with strokeAlso called a "brain attack" and happens when brain cells die because of inadequate blood flow. 20% of cases are a hemorrhage in the brain caused by a rupture or leakage from a blood vessel. 80% of cases are also know as a "schemic stroke", or the formation of a blood clot in a vessel supplying blood to the brain. (n=208) by comparing performance on 5 OT-APST subtests with performance on 5 corresponding LOTCA-II and LOTCA-G areas. Poor to excellent correlations were reported between OT-APST and LOTCA-II area scores (range d=0.27 to d=0.66); and poor to excellent correlations between OT-APST and LOTCA-G area scores (range d=0.25 to d=0.80), using Somers’s d concordance correlations.

Zwecker et al. (2002) reported on correlations between cognitive status and functional motor outcomes in patients with strokeAlso called a "brain attack" and happens when brain cells die because of inadequate blood flow. 20% of cases are a hemorrhage in the brain caused by a rupture or leakage from a blood vessel. 80% of cases are also know as a "schemic stroke", or the formation of a blood clot in a vessel supplying blood to the brain. (n=66). Functional motor outcomes were measured according to efficacy and efficiency of FIM motor scores (isolated from total FIM scores) and Montebello Rehabilitation Factor Score (MRFS). An adequate correlationThe extent to which two or more variables are associated with one another. A correlation can be positive (as one variable increases, the other also increases - for example height and weight typically represent a positive correlation) or negative (as one variable increases, the other decreases - for example as the cost of gasoline goes higher, the number of miles driven decreases. There are a wide variety of methods for measuring correlation including: intraclass correlation coefficients (ICC), the Pearson product-moment correlation coefficient, and the Spearman rank-order correlation.
was found between LOTCA scores and MRFS efficacy (r=0.34, p<0.001) but poor correlations were reported between LOTCA scores and FIM motor efficacy (r=0.25, p<0.05), FIM efficiency (r=0.16) and MRFS efficiency (r=0.19), using Pearson correlations.

Predictive.
No studies have examined the predictive validityA form of criterion validity that examines a measure's ability to predict some subsequent event. Example: can the Berg Balance Scale predict falls over the following 6 weeks? The criterion standard in this example would be whether the patient fell over the next 6 weeks.
of the LOTCA with patients with strokeAlso called a "brain attack" and happens when brain cells die because of inadequate blood flow. 20% of cases are a hemorrhage in the brain caused by a rupture or leakage from a blood vessel. 80% of cases are also know as a "schemic stroke", or the formation of a blood clot in a vessel supplying blood to the brain..

Construct:
Katz et al. (1989) conducted factor analysis of the original LOTCA and reported suitable construct validityReflects the ability of an instrument to measure an abstract concept, or construct. For some attributes, no gold standard exists. In the absence of a gold standard , construct validation occurs, where theories about the attribute of interest are formed, and then the extent to which the measure under investigation provides results that are consistent with these theories are assessed.
for the Perception, Visuomotor Organization and Thinking Operations areas.

Su et al. (2000) reported that the LOTCA Orientation and Perception areas demonstrate suitable construct validityReflects the ability of an instrument to measure an abstract concept, or construct. For some attributes, no gold standard exists. In the absence of a gold standard , construct validation occurs, where theories about the attribute of interest are formed, and then the extent to which the measure under investigation provides results that are consistent with these theories are assessed.
to measure two theoretically and statistically distinct theoretical constructs.

Convergent/Discriminant.
Katz et al. (1995) reported a statistically significant difference in the time taken to complete the LOTCA and the LOTCA-G in a group of healthy adults, using two-way ANOVA (F=11.26, P<.0001), with less time taken to complete the LOTCA-G than the LOTCA.

Cooke et al. (2006b) examined the convergent validityA type of validity that is determined by hypothesizing and examining the overlap between two or more tests that presumably measure the same construct. In other words, convergent validity is used to evaluate the degree to which two or more measures that theoretically should be related to each other are, in fact, observed to be related to each other.
of the LOTCA (2nd edition) and the LOTCA-G area means with the OT-APST subscaleMany measurement instruments are multidimensional and are designed to measure more than one construct or more than one domain of a single construct. In such instances subscales can be constructed in which the various items from a scale are grouped into subscales. Although a subscale could consist of a single item, in most cases subscales consist of multiple individual items that have been combined into a composite score (National Multiple Sclerosis Society).
means in patients with strokeAlso called a "brain attack" and happens when brain cells die because of inadequate blood flow. 20% of cases are a hemorrhage in the brain caused by a rupture or leakage from a blood vessel. 80% of cases are also know as a "schemic stroke", or the formation of a blood clot in a vessel supplying blood to the brain., using Spearman’s rho correlations. Statistically significant correlations were found between the 5 areas of the LOTCA (2nd edition) and LOTCA-G, and the 5 corresponding subscales of the OT-APST (p<0.01). Correlations ranged from adequate (0.33 for OT-APST Apraxia subtest and LOTCA Motor Praxis area/LOTCA-G Praxis area) to excellent (0.80 for OT-APST Constructional skills subtest and LOTCA-G Visuomotor Organization area).

Zwecker et al. (2002) reported adequate correlations between the LOTCA and MMSE (r= 0.588, p<0.001) and between the LOTCA and FIM cognitive subtest (r=0.471, p<0.001) in patients with strokeAlso called a "brain attack" and happens when brain cells die because of inadequate blood flow. 20% of cases are a hemorrhage in the brain caused by a rupture or leakage from a blood vessel. 80% of cases are also know as a "schemic stroke", or the formation of a blood clot in a vessel supplying blood to the brain. (n=66), using Pearson’s CorrelationThe extent to which two or more variables are associated with one another. A correlation can be positive (as one variable increases, the other also increases - for example height and weight typically represent a positive correlation) or negative (as one variable increases, the other decreases - for example as the cost of gasoline goes higher, the number of miles driven decreases. There are a wide variety of methods for measuring correlation including: intraclass correlation coefficients (ICC), the Pearson product-moment correlation coefficient, and the Spearman rank-order correlation.
.

Su et al. (2000) reported significant correlations between the LOTCA, Rivermead Perceptual Assessment Battery (RPAB), and the Motor-Free Visual Perception Test (MVPT), in patients with strokeAlso called a "brain attack" and happens when brain cells die because of inadequate blood flow. 20% of cases are a hemorrhage in the brain caused by a rupture or leakage from a blood vessel. 80% of cases are also know as a "schemic stroke", or the formation of a blood clot in a vessel supplying blood to the brain. (n=44). Excellent correlations were reported between LOTCA Thinking Operations and MVPT (r = 0.72, p<0.0001); LOTCA Visuomotor Organization and MVPT (r=0.79, p<0.0001); and LOCTA Visuomotor Organisation and RPAB Spatial Awareness (r=0.74, p<0.0001). Adequate correlations were reported between LOTCA Orientation and RPAB Sequencing"The coordination and proper ordering of the steps that comprise the task, requiring a proper allotment of attention to each step" (Lezak, 1989; as cited in (Baum, Morrison, Hahn & Edwards, 2007))
(r=0.46, p<0.01) and Object Completion (r=0.38, p<0.01) subtests; LOTCA Perception and RPAB Sequencing"The coordination and proper ordering of the steps that comprise the task, requiring a proper allotment of attention to each step" (Lezak, 1989; as cited in (Baum, Morrison, Hahn & Edwards, 2007))
(r=0.38, p<0.01); LOTCA Visuomotor Organization and RPAB Sequencing"The coordination and proper ordering of the steps that comprise the task, requiring a proper allotment of attention to each step" (Lezak, 1989; as cited in (Baum, Morrison, Hahn & Edwards, 2007))
(r=0.52, p<0.01); and LOTCA Thinking Operations and RPAB Sequencing"The coordination and proper ordering of the steps that comprise the task, requiring a proper allotment of attention to each step" (Lezak, 1989; as cited in (Baum, Morrison, Hahn & Edwards, 2007))
(r=0.56, p<0.0001), Object completion (r=0.36, p<0.05), Figure-ground Discrimination (r=0.51, p<0.01) and Spatial Awareness (r=0.56, p<0.0001) subtests.

Katz et al. (2000) examined correlations between cognitive performance and daily function in two subgroups of adult with right hemisphere strokeAlso called a "brain attack" and happens when brain cells die because of inadequate blood flow. 20% of cases are a hemorrhage in the brain caused by a rupture or leakage from a blood vessel. 80% of cases are also know as a "schemic stroke", or the formation of a blood clot in a vessel supplying blood to the brain. (n=40 vs. patients without unilateral spatial neglect, n=21), using Spearman’s correlationThe extent to which two or more variables are associated with one another. A correlation can be positive (as one variable increases, the other also increases - for example height and weight typically represent a positive correlation) or negative (as one variable increases, the other decreases - for example as the cost of gasoline goes higher, the number of miles driven decreases. There are a wide variety of methods for measuring correlation including: intraclass correlation coefficients (ICC), the Pearson product-moment correlation coefficient, and the Spearman rank-order correlation.
analysis. Cognitive skills were measured using the LOTCA at admission to and discharge from inpatient rehabilitation, and only using the Block Design, Puzzle and Clock Drawing subtests at 6-month follow-up. Functional skills were assessed using all or some of the FIM total, motor and cognitive scores, Rabideau Kitchen Evaluation – Revised (RKE-R) (sandwich and drink preparation), and Phone Use tests at these time points. In the neglect group, adequate to excellent correlations were reported between LOTCA Visuomotor Organisation and Thinking Operations areas and functional tests at admission, discharge and follow-up (range r=0.46 to 0.80). Adequate to excellent correlations were reported between LOTCA Perception and functional tests at discharge only (range r=-0.54 to 0.75). Poor correlations were found between LOTCA Orientation and functional tasks in this subgroup. The authors reported a possible confounding effect with this sub-group, given the visual/spatial demands of the LOTCA. In the non-neglect group, poor to excellent correlations were reported between FIM Cognitive and LOTCA Orientation (r=0.05), Perception (r=0.59), Visuomotor Organisation (r=0.67) and Thinking Operations (r=0.58) areas at admission. No significant correlations were reported with FIM total or FIM motor for any LOTCA area on admission. Adequate to excellent correlations were reported between LOTCA Visuomotor Organisation and Thinking Operations subtests and functional tasks at discharge and follow up (range r=0.43 to 0.62).

Known Group:
Katz et al. (1989) examined known group validityThe degree to which an assessment measures what it is supposed to measure.
of the original LOTCA among patients with traumatic brain injury (n=20), patients with strokeAlso called a "brain attack" and happens when brain cells die because of inadequate blood flow. 20% of cases are a hemorrhage in the brain caused by a rupture or leakage from a blood vessel. 80% of cases are also know as a "schemic stroke", or the formation of a blood clot in a vessel supplying blood to the brain. (n=28), and healthy adults (n=55), using the Wilcoxon testThe Wilcoxon test is a nonparametric test that compares two paired groups. This test calculates and then analyzes the differences between the pairs. The Wilcoxon Rank Sum test is used to determine whether two scores have the same continuous distribution. The Wilcoxon Signed Rank test is suitable to use as an alternative to the paired t-test when the scores are not normally distributed.
. Significant differences among the three subgroups were found on initial assessment at the time of referral (p=0.0001).

Katz et al. (1995) compared LOTCA scores between healthy adults (n=29) and patients with strokeAlso called a "brain attack" and happens when brain cells die because of inadequate blood flow. 20% of cases are a hemorrhage in the brain caused by a rupture or leakage from a blood vessel. 80% of cases are also know as a "schemic stroke", or the formation of a blood clot in a vessel supplying blood to the brain. (n=24), using the Wilcoxon testThe Wilcoxon test is a nonparametric test that compares two paired groups. This test calculates and then analyzes the differences between the pairs. The Wilcoxon Rank Sum test is used to determine whether two scores have the same continuous distribution. The Wilcoxon Signed Rank test is suitable to use as an alternative to the paired t-test when the scores are not normally distributed.
. Significant between group differences (range p=0.0002 to p=0.04) were reported for Orientation, Perception, Visuomotor Organization and Thinking Operations areas (excluding the Spatial Perception, Praxis, Coloured Block Design, Plain Block Design, Puzzle, Drawing a Clock, Categorization, Risk Object Classification – ROC -Unstructured and Pictorial Sequence B subtests). The group of healthy adults scored higher on all areas of the LOTCA than the group of patients with strokeAlso called a "brain attack" and happens when brain cells die because of inadequate blood flow. 20% of cases are a hemorrhage in the brain caused by a rupture or leakage from a blood vessel. 80% of cases are also know as a "schemic stroke", or the formation of a blood clot in a vessel supplying blood to the brain..

Katz et al. (1995) reported differences (although no statistical data were provided) between healthy adults and healthy elderly adults on the Visuomotor Organization and Thinking Operation areas of the LOTCA.

Katz et al (1997) compared performance between adults aged 18 – 30 years (n=36) and adults aged 58 – 70 years (n=36) on three versions of the LOTCA puzzle reproduction task (original direct placement version; subplacement version; and LOTCA-G version). Two-way anaylsis of variance (ANOVA) showed significant differences in terms of age (p<0.0001), puzzle version (p<0.0002) and age-by-version interaction (p<0.01). Older adults took significantly longer than younger adults to complete each version of the puzzle. While the younger group of adults took significantly longer to complete the subplacement version as compared to the other two versions (original; LOTCA-G version), the older adults were able to complete the LOTCA-G version at a significantly faster rate than the other two versions (original version; subplacement version).

Katz et al (2000) compared LOTCA performance between two subgroups of adults with right hemisphere strokeAlso called a "brain attack" and happens when brain cells die because of inadequate blood flow. 20% of cases are a hemorrhage in the brain caused by a rupture or leakage from a blood vessel. 80% of cases are also know as a "schemic stroke", or the formation of a blood clot in a vessel supplying blood to the brain. (patients with unilateral spatial neglect, n=19 vs. patients without unilateral spatial neglect, n=21) on admission to and discharge from inpatient rehabilitation. Patients with neglect were reported to score significantly worse on the Overlapping Figures subtest, Perception area total score, and all Visuomotor Organisation and Thinking Operations subtests and area total scores at admission and discharge (range p=0.02 to p=0.0001; Wilcoxon Rank Sum statistic).

Annes et al. (1996) compared LOTCA maximum scores between healthy young adults aged 17-25 years (n=49) and healthy older adults aged 40-75 years (n=49), using Fisher’s Exact Test or Yate’s chi square as appropriate. No significant differences were reported for Orientation or Perception areas. Younger adults performed significantly better on the Copying Geometric Forms (p=0.01), Plain Block Design (p=0.024) and Pictorial Sequence A (p=0.002) subtests, while older adults were reported to perform significantly better on the Geometric Sequence (p=0.046) subtest. The authors concluded that separate LOTCA norms are not required for the two age groups. While a significant difference was seen for the ROC-Unstructured subtest, it is considered that this difference was due to an error in the administration of the test.
Note: The maximum score was used rather than mean or standard deviations, due to a ceiling effectA ceiling effect occurs when test items aren't challenging enough for a group of individuals. Thus, the test score will not increase for a subsample of people who may have clinically improved because they have already reached the highest score that can be achieved on that test. In other words, because the test has a limited number of difficult items, the most highly functioning individuals will score at the highest possible score. This becomes a measurement problem when you are trying to identify changes - the person may continue to improve but the test does not capture that improvement. Example: A memory test that assesses how many words a participant can recall has a total of five words that each participant is asked to remember. Because most individuals can remember all five words, this measure has a ceiling effect. See also "floor effect." produced by the consistently high performance of subjects within both groups.

Annes et al. (1996) reported a significant difference in time taken to complete the LOTCA Visuomotor Organization area between healthy young adults aged 17-25 years (n=49) and healthy older adults aged 40-75 years (n=49), with the younger age group completing 6 of 7 subtests more quickly (Copying Geometric Forms, p<0.01; Pegboard Construction, p<0.01; Coloured Block Design, p<0.01; Reproduction of a 2D Model, p<0.05; Reproduction of a Model, p<0.05; and Drawing a Clock p<0.05; but not Plain Block Design).

Cermak et al. (1995) compared LOTCA performance between American (n=25) and Israeli (n=56) patients with CVA. Using the total sample group, they also compared performance between patients with right CVA (n=45) and patients with left CVA (n=36), using t-tests. Israeli participants were found to perform significantly better than American participants on the Orientation to Time subtest (p<0.01) in both subgroups (right CVA and left CVA); the Drawing a Clock (p<0.01) and Risk Object Classification – structured (p<0.05) subtests in the right CVA subgroup; and the Object Constancy (p<0.01) subtest in the left CVA subgroup. Comparison according to side of lesion showed that patients with right CVA performed significantly better (p<0.05) than those with left CVA on the Orientation to Time, Object Constancy and Spatial Perception subtests within the American subgroup; and on the Praxis subtest within the Israeli subgroup (p<0.01). However, patients with left CVA performed significantly better (p<0.05) than patients with right CVA on the Pegboard Construction subtest amongst both American and Israeli participants. It should be noted that Israeli participants were significantly younger than American participants in both the right CVA (mean age 58.5 vs 64.3, t = 2.25, p < 0.05) and left CVA (mean age 55.0 vs. 69.0, t=3.09, p<0.01) groups. The correlationThe extent to which two or more variables are associated with one another. A correlation can be positive (as one variable increases, the other also increases - for example height and weight typically represent a positive correlation) or negative (as one variable increases, the other decreases - for example as the cost of gasoline goes higher, the number of miles driven decreases. There are a wide variety of methods for measuring correlation including: intraclass correlation coefficients (ICC), the Pearson product-moment correlation coefficient, and the Spearman rank-order correlation.
between LOTCA subtests and age were low to moderate for most subtests, but was moderate for the Orientation to Time subtest, in which the Israeli group performed significantly better than the American group.

Su et al. (2000) compared the perceptual performance of patients with intracerebral hemorrhage (n=22) to patients with ischemia (n=22) early after strokeAlso called a "brain attack" and happens when brain cells die because of inadequate blood flow. 20% of cases are a hemorrhage in the brain caused by a rupture or leakage from a blood vessel. 80% of cases are also know as a "schemic stroke", or the formation of a blood clot in a vessel supplying blood to the brain. and found that patients with intracerebral hemorrhage performed significantly worse on the LOTCA Thinking Operations area (p=0.007). No significant differences were reported between subjects with right-sided lesions and subjects with left-sided lesions for any LOTCA area.

Josman and Katz (2006) examined the relationship between formal categorization-sorting tests and functional sorting tasks among individuals with schizophrenia (n=37), patients post strokeAlso called a "brain attack" and happens when brain cells die because of inadequate blood flow. 20% of cases are a hemorrhage in the brain caused by a rupture or leakage from a blood vessel. 80% of cases are also know as a "schemic stroke", or the formation of a blood clot in a vessel supplying blood to the brain. (n=18) and healthy adults (n=15), using the LOTCA Picture Sort subtest, Wisconsin Card Sorting Test, Short Category Test, Risk Object Classification and five functional daily tasks (sorting laundry, utensils, invoices, and two shopping lists). One way ANCOVA revealed a significant difference in the mean performance of the LOTCA Picture Sort subtest (F= 7.57, P=0.001). Post hoc Scheffe tests revealed that patients with strokeAlso called a "brain attack" and happens when brain cells die because of inadequate blood flow. 20% of cases are a hemorrhage in the brain caused by a rupture or leakage from a blood vessel. 80% of cases are also know as a "schemic stroke", or the formation of a blood clot in a vessel supplying blood to the brain. performed worse than individuals with schizophrenia (P<0.05) and healthy adults (P<0.05).

Katz et al (1995) compared LOTCA-G scores between healthy older adults (n=43) and patients with strokeAlso called a "brain attack" and happens when brain cells die because of inadequate blood flow. 20% of cases are a hemorrhage in the brain caused by a rupture or leakage from a blood vessel. 80% of cases are also know as a "schemic stroke", or the formation of a blood clot in a vessel supplying blood to the brain. (n=33), using the Wilcoxon sign test. Healthy older adults performed significantly better than patients with strokeAlso called a "brain attack" and happens when brain cells die because of inadequate blood flow. 20% of cases are a hemorrhage in the brain caused by a rupture or leakage from a blood vessel. 80% of cases are also know as a "schemic stroke", or the formation of a blood clot in a vessel supplying blood to the brain. for the Orientation, Perception, Visuomotor Organization and Thinking Operations areas (range p=0.0001 to p=0.05), excluding the Praxis and Coloured Blocks Design subtests. Significant differences in the time taken to complete the LOTCA-G were also found between the 2 groups (P<0.0001), with the healthy older adults completing the assessment more quickly than patients with strokeAlso called a "brain attack" and happens when brain cells die because of inadequate blood flow. 20% of cases are a hemorrhage in the brain caused by a rupture or leakage from a blood vessel. 80% of cases are also know as a "schemic stroke", or the formation of a blood clot in a vessel supplying blood to the brain..

Bar-Haim Erez & Katz (2003) compared LOTCA-G scores between healthy adults (n=43) and individuals with dementia (n=30). Healthy adults performed significantly better than individuals with dementia on all subtests (p=0.000), except for the Object Identification and Shape Identification subtests. Health adults completed the test significantly quicker than individuals with dementia (p<0.000). Comparison of healthy adults and two subgroups of individuals with dementia (mild dementia, n=13; moderate dementia, n=17) by one way ANOVA showed significant F tests for all areas (p<0.000, except visual perception p<0.05). Post hoc Scheffe testing showed that individuals with mild dementia performed better than individuals with moderate dementia in the areas of Orientation, Visual Perception, Visuomotor Organisation, Thinking Operations and Memory. Mann-Whitney analysis of subtest mean scores from the two dementia subgroups further showed that individuals with mild dementia performed significantly better than individuals with moderate dementia on 10 subtests (Orientation to Place, Orientation to Time, Spatial Perception-Self and Surrounding, Motor Imitation, Utilisation of Objects, Copying Geometric Forms, Pegboard Construction, Block Design (Colour), Categorisation, Memory of a Famous Personality), indicating that the LOTCA-G is sensitive to degree of dementia.

Responsiveness

No studies have reported on the responsivenessThe ability of an instrument to detect clinically important change over time.
of the LOTCA.

References

• Annes, G., Katz, N., & Cermak, S. (1996). Comparison of younger and older healthy American adults on the Loewenstein Occupational Therapy Cognitive Assessment. Occupational Therapy International, 3, 157-173.
• Bar-Haim Erez, A., & Katz, N. (2003). Cognitive profiles of individuals with dementia and healthy elderly: The Loewenstein Occupational Therapy Cognitive Assessment (LOTCA-G). Physical and Occupational Therapy in Geriatrics, 22, 29-42.
• Cermak, S. A., Katz, N., McGuire, E., Greenbaum, S., Peralta, C., & Flanagan, V.M. (1995). Performance of Americans and Israelis with cerebrovascular accident on the Loewenstein Occupational Therapy Cognitive Assessment. American Journal of Occupational Therapy, 49, 500-506.
• Cooke, D. M., McKenna, K., Fleming, J. & Darnell, R. (2006a). Criterion validity of the Occupational Therapy Adult Percepetual Screening Test (OT-APST). Scandinavian Journal of Occupational Therapy, 13, 38-48.
• Cooke, D. M., McKenna, K., Fleming, J. & Darnell, R. (2006b). Construct and ecological validity of the Occupational Therapy Adult Perceptual Screening Test (OT-APST). Scandinavian Journal of Occupational Therapy, 13, 49-61.
• Jang, Y., Chern, J-S., & Lin, K-C. (2009). Validity of the Loewenstein Occupational Therapy Cognitive Assessment in people with intellectual disabilities. American Journal of Occupational Therapy, 63, 414-244.
• Josman, N., Abdallah, T. M., & Engel-Yeger, B. (2010). Cultural factors affecting the differential performance of Israeli and Palestinian children on the Loewenstein Occupational Therapy Cognitive Assessment. Research in Developmental Disabilities, 31, 656-663.
• Josman, N., & Katz, N. (2006). Relationships of categorization on tests and daily tasks in patients with schizophrenia, post-stroke patients and healthy controls. Psychiatry Research, 141, 15-28.
• Katz, N., Champagne, D., & Cermak, S. (1997). Comparison of the performance of younger and older adults on three versions of a puzzle reproduction task. American Journal of Occupational Therapy, 51, 562-568.
• Katz, N., Elazar, B., & Itzkovich, M. (1995). Construct validity of a geriatric version of the Loewenstein Occupational Therapy Cognitive Assessment (LOTCA) battery. Physical and Occupational Therapy in Geriatrics, 13, 31-46.
• Katz, N., Hartman-Maeir, A., Ring, H., & Soroker, N. (2000). Relationships of cognitive performance and daily function of clients following right hemisphere stroke: Predictive and ecological validity of the LOTCA battery. Occupational Therapy Journal of Research, 20, 3-17.
• Katz, N., Itzkovich, M., & Averbuch, S. (2002). The Loewenstein Occupational Therapy Cognitive Assessment. Archives of Physical Medicine and Rehabilitation, 83, 1179.
• Katz, N., Itzkovich, M., Averbuch, S., & Elazar, B. (1989). Loewenstein Occupational Therapy Cognitive Assessment (LOTCA) battery for brain-injured patients: Reliability and validity. American Journal of Occupational Therapy, 43, 184-192.
• Su, C-Y., Chang, J-J., Chen, H-M., Su, C-J., Chien, T-H., & Huang, M-H. (2000). Perceptual differences between stroke patients with cerebral infarction and intracerebral hemorrhage. Archives of Physical Medicine and Rehabilitation, 81, 706-714.
• Su, C-Y., Chen, W-L., Tsai, P-C., Tsai, C-Y., & Su, W-L. (2007). Psychometric properties of the Loewenstein Occupational Therapy Cognitive Assessment-Second Edition in Taiwanese persons with schizophrenia. American Journal of Occupational Therapy, 61, 108-118.
• Su, C-Y., Lin, Y-H., Chen-Sea, M-J., & Yang, M-J. (2007). A confirmatory factor analysis of the Chinese version of the Loewenstein Occupational Therapy Cognitive Assessment-second edition in a Taiwanese mixed clinical sample. Occupational Therapy Journal of Research, 27, 71-80.
• Zwecker, M., Levenkrohn, S., Fleisig, Y., Zeilig, G., Ohry, A., & Adunsky, A. (2002). Mini-Mental State Examination, cognitive FIM instrument, and the Loewenstein Occupational Therapy Cognitive Assessment: Relation to functional outcome of stroke patients. Archives of Physical Medicine and Rehabilitation, 83, 342-5.

See the measure

How to obtain the LOTCA?

The LOTCA can be purchased online from http://store.grovergear.com/, http://www.ot-innovations.com, or http://therapro.com.

Purpose

The Occupational Therapy Adult Perceptual Screening Test (OT-APST) is a standardized screening measure that enables occupational therapists to test for the presence of impairment in visual perception across each of the major constructs of visual perception and praxis, including the problems most frequently occurring after stroke.

In-Depth Review

Purpose of the measure

The Occupational Therapy Adult Perceptual ScreeningTesting for disease in people without symptoms.
Test (OT-APST) is a standardized screeningTesting for disease in people without symptoms.
measure that enables occupational therapists to test for the presence of impairment in visual perception across each of the major constructs of visual perception and praxis, including the problems most frequently occurring after strokeAlso called a "brain attack" and happens when brain cells die because of inadequate blood flow. 20% of cases are a hemorrhage in the brain caused by a rupture or leakage from a blood vessel. 80% of cases are also know as a "schemic stroke", or the formation of a blood clot in a vessel supplying blood to the brain..

Available versions

The OT-APST was developed by Deidre M. Cooke in 1992 and was first published in 1993 (Cooke, 1993). The OT-APST was revised in 2001.

Features of the measure

Items:

The OT-APST has 25 items in 7 subtest areas (Agnosia; Visuospatial Relations – Unilateral neglect and Body scheme -; Constructional skills; Apraxia; Acalculia; Functional Skills). Several of the items contribute to assessment of more than one area and are only performed once. The subtests and their respective items are organized as follows:

Agnosias (5 items)

• Colour agnosia: The client is requested to name/identify six colors in an array to evaluate color recognition skills.
• Object agnosia: The client is presented with a stapler that he/she must name and describe in terms of its use to demonstrate object recognition and naming.
• Figure-ground: The client must recognize five items in an overlapping array to demonstrate figure-ground/perceptual closure skills.
• Shape constancy: The client is presented with a mixed array of 10 shapes of varying sizes and positioned at different angles. The client must name/point on command to four common shapes to demonstrate shape recognition ability.
• Reading-alexia: The client is asked to read a passage of text that has indentations of random lengths on both sides of the page to be sensitive to attention/neglect changes to both the left and right side of space.

Visuospatial relations – Unilateral neglect and Body scheme

Unilateral neglect (5 items)

• Clock drawing
• Copying a house diagram
• Writing: The client is asked to provide a handwriting sample that consists of writing their name and address.
• Reading a paragraph: The client is asked to read a passage of 12 lines to assess reading and visual scanningDuring this intervention the person with USN is encouraged to conduct voluntary eye movements toward the neglected visual field (usually the left side) by performing a task in that hemispace. The treatment often includes a visual target that the patient uses as an anchor to direct voluntary gaze control while scanning.
  accuracy, to detect for the presence of neglect or the impact of visual field loss on reading, and to screen for alexia.
• Telling time

Body scheme (4 items)

• Body parts self: The client is asked to identify his/her own body parts.
• Body parts therapist: The client is asked to identify the examiner’s body parts.
• Left/right discrimination: The client is requested to differentiate sides (left and right).
• Directions/position in space: The client is asked to move colored blocks to different positions in relation to each other (e.g. ‘on top of’ or ‘behind’), or to describe the color or point to the block that is ‘furthest away’ from and ‘nearest’ to him/her on the tabletop.

Constructional skills (3 items):

• Graphic constructional skills: The client is asked to draw a clock and place its hands at a designated time. They must also copy a house.
• Two-dimensional construction: The client is asked to reproduce colored block patterns in two-dimensional planes by copying a model provided.
• Three-dimensional construction: Three-dimensional models rather than pictures of these models are copied.

Apraxia (6 items):

• Smile command and copy
• Wave right hand-command and copy
• Wave left hand-command and copy
• Stapler hold command and copy
• Pen use for writing
• Writing

Acalculia (1 item):

• The client is asked to perform simple one- and two-digit addition and subtraction calculations that are set at a grade two level.

Functional skills (5 items):

• Reading
• Writing
• Calculations: The client must complete simple mathematical calculations.
• Telling time
• Use of stapler

Futher observations of the client’s performance of other activitiesAs defined by the International Classification of Functioning, Disability and Health, activity is the performance of a task or action by an individual. Activity limitations are difficulties in performance of activities. These are also referred to as function.
of daily living such as dressing and grooming, in addition to performing a kitchen task are recommended but are not formally included in the OT-APST.

Other:

The length of time taken to complete the OT-APST in its entirety is recorded as a general indicator of the information-processing speed of the client and to reflect the client’s perceptual processing ability.

Scoring:

Scores for items in each construct or subtest area are summed to allow interpretation of patterns of impairments and to compare with normative data, but not to produce a total score for the OT-APST.

The table below outlines the subtest total scores and individual item scores of the OT-APST:

(Cooke, McKenna, Fleming, & Darnell, 2005a)

Cooke, McKenna, Fleming, and Darnell (2006c) examined the impact of age, education, and gender on OT-APST scoring based on the performance of 356 healthy Australian adults aged 16-97 years. When mean scores were compared for each subscaleMany measurement instruments are multidimensional and are designed to measure more than one construct or more than one domain of a single construct. In such instances subscales can be constructed in which the various items from a scale are grouped into subscales. Although a subscale could consist of a single item, in most cases subscales consist of multiple individual items that have been combined into a composite score (National Multiple Sclerosis Society).
, the most significant differences were observed with age. Gender and level of education did not significantly impact on OT-APST performance of the healthy participants. Increasing age was significantly associated with reduced performance on all subscales but the Acalculia and Body scheme subscales. The age at which the most significant differences in OT-APST performance occurred was at age 75 years and above.

The tables below provides the cutoff scores indicating impairment for each of the subscales of the OT-APST, stratified by age group:

(Cooke, McKenna, Fleming, & Darnell, 2006c)

Time:

The OT-APST can be administered within 20 to 25 minutes (Cooke, McKenna, & Fleming, 2005a).

Subscales:

The OT-APST has 7 subscales: Agnosia; Visuospatial Relations – Unilateral neglect and Body scheme -; Constructional skills; Apraxia; Acalculia; Functional Skills.

Equipment:

All of the equipment required for completion of the OT-APST is provided in the assessment kit that can be purchased online at: http://www.functionforlife.com.au/images/OT-APSTorderformA4.pdf

Training:

No formal training is required for the OT-APST. The manual provides standard directions for the administration and scoring of the measure.

Alternative forms of the OT-APST

None.

Client suitability

Can be used with:

• Patients with strokeAlso called a "brain attack" and happens when brain cells die because of inadequate blood flow. 20% of cases are a hemorrhage in the brain caused by a rupture or leakage from a blood vessel. 80% of cases are also know as a "schemic stroke", or the formation of a blood clot in a vessel supplying blood to the brain..

Should not be used with:

• Completion of the OT-APST requires adequate comprehension of simple verbal instructions.
• It is not suitable for individuals with severe auditory comprehension problems.
• It is not suitable for individuals who are unable to use either hand for task completion.
• The OT-APST is not suitable for individuals whose level of arousal or attentional capacity precludes participationAs defined by the International Classification of Functioning, Disability and Health, participation is an individual's involvement in life situations in relation to health conditions, body functions or structures, activities, and contextual factors. Participation restrictions are problems an individual may have in the manner or extent of involvement in life situations. for the necessary time required for task completion.
• The OT-APST is not suitable for individuals with receptive language problems, however, alternative methods of test administration are included for clients with expressive language problems.

In what languages is the measure available?

To our knowledge based on a review of the scientific literature, the OT-APST has not been formally translated and validated in other languages.

Summary

Psychometric Properties

Overview

We conducted a literature search to identify all relevant publications on the psychometric properties of the OT-APST. To our knowledge, the creators of the OT-APST have personally gathered the majority of psychometric data that are currently published on the scale.

Reliability

Internal consistencyA method of measuring reliability . Internal consistency reflects the extent to which items of a test measure various aspects of the same characteristic and nothing else. Internal consistency coefficients can take on values from 0 to 1. Higher values represent higher levels of internal consistency.:
Cooke, McKenna, Fleming, Darnell (2006a) examined the internal consistencyA method of measuring reliability . Internal consistency reflects the extent to which items of a test measure various aspects of the same characteristic and nothing else. Internal consistency coefficients can take on values from 0 to 1. Higher values represent higher levels of internal consistency. of the OT-APST subscales Agnosia, Body scheme, Neglect, and Constructional skills in 208 participants with strokeAlso called a "brain attack" and happens when brain cells die because of inadequate blood flow. 20% of cases are a hemorrhage in the brain caused by a rupture or leakage from a blood vessel. 80% of cases are also know as a "schemic stroke", or the formation of a blood clot in a vessel supplying blood to the brain.. The internal consistencyA method of measuring reliability . Internal consistency reflects the extent to which items of a test measure various aspects of the same characteristic and nothing else. Internal consistency coefficients can take on values from 0 to 1. Higher values represent higher levels of internal consistency. alpha coefficients for these subscales ranged between 0.71 and 0.83, indicating adequate to excellent levels of internal consistencyA method of measuring reliability . Internal consistency reflects the extent to which items of a test measure various aspects of the same characteristic and nothing else. Internal consistency coefficients can take on values from 0 to 1. Higher values represent higher levels of internal consistency..

Test-retest:
Cooke, McKenna, Fleming, and Darnell (2005b) examined the test-retest reliabilityA way of estimating the reliability of a scale in which individuals are administered the same scale on two different occasions and then the two scores are assessed for consistency. This method of evaluating reliability is appropriate only if the phenomenon that the scale measures is known to be stable over the interval between assessments. If the phenomenon being measured fluctuates substantially over time, then the test-retest paradigm may significantly underestimate reliability. In using test-retest reliability, the investigator needs to take into account the possibility of practice effects, which can artificially inflate the estimate of reliability (National Multiple Sclerosis Society).
of the OT-APST by having one rater administer and score the OT-APST to 15 patients with strokeAlso called a "brain attack" and happens when brain cells die because of inadequate blood flow. 20% of cases are a hemorrhage in the brain caused by a rupture or leakage from a blood vessel. 80% of cases are also know as a "schemic stroke", or the formation of a blood clot in a vessel supplying blood to the brain. and videotape their performance. The same rater then assessed the same patients at the same time of day, 2 weeks later. On 14 of the 25 items, there was 100% agreement between the first and second assessments. For the 11 remaining items, the percentage agreement ranged between 70% and 90%, with the exception of one item, Two-dimensional Constructional skills, which had only 20% agreement. Intraclass correlationThe extent to which two or more variables are associated with one another. A correlation can be positive (as one variable increases, the other also increases - for example height and weight typically represent a positive correlation) or negative (as one variable increases, the other decreases - for example as the cost of gasoline goes higher, the number of miles driven decreases. There are a wide variety of methods for measuring correlation including: intraclass correlation coefficients (ICC), the Pearson product-moment correlation coefficient, and the Spearman rank-order correlation.
coefficients (ICCs) were calculated for 6 of the 13 items, where the percentage agreement was less than 100% and the scale of the item was appropriate for this form of correlation calculation. The ICCs were considered excellent, ranging from 0.76 to 0.95.

Intra-rater:
Cooke, McKenna, Fleming, and Darnell (2005b) examined the intra-rater reliabilityThis is a type of reliability assessment in which the same assessment is completed by the same rater on two or more occasions. These different ratings are then compared, generally by means of correlation. Since the same individual is completing both assessments, the rater's subsequent ratings are contaminated by knowledge of earlier ratings.
of the OT-APST by having 9 occupational therapy raters each score 5 patients with strokeAlso called a "brain attack" and happens when brain cells die because of inadequate blood flow. 20% of cases are a hemorrhage in the brain caused by a rupture or leakage from a blood vessel. 80% of cases are also know as a "schemic stroke", or the formation of a blood clot in a vessel supplying blood to the brain. from video recordings. Following a time delay of 2 weeks, all of the raters viewed the videos again and scored the same five participants in a different randomized order. On 12 of the 25 items, there was 100% agreement between the scores for the first and second video scoring sessions. On the other 13 items, the percentage agreement for raters between the first and second scoring sessions ranged from 83% to 98%. ICCs ranged from adequate (ICC = 0.64) to excellent (ICC = 1.0).

Inter-rater:
Cooke, McKenna, Fleming, and Darnell (2005b) examined the inter-rater reliabilityA method of measuring reliability . Inter-rater reliability determines the extent to which two or more raters obtain the same result when using the same instrument to measure a concept.
of the OT-APST by having one rater administer and score the OT-APST to 15 patients with stroke and videotape their performance. Nine raters were then allocated to score 5 patients. Each video was scored by three separate raters and presented in random order to each rater. Intraclass correlationThe extent to which two or more variables are associated with one another. A correlation can be positive (as one variable increases, the other also increases - for example height and weight typically represent a positive correlation) or negative (as one variable increases, the other decreases - for example as the cost of gasoline goes higher, the number of miles driven decreases. There are a wide variety of methods for measuring correlation including: intraclass correlation coefficients (ICC), the Pearson product-moment correlation coefficient, and the Spearman rank-order correlation.
coefficients (ICCs) ranged from adequate (ICC = 0.66 for the Clock item) to excellent (ICC = 1.00 for the items Wave left hand-command and copy, and Two-dimensional Constructional skills). On 12 of the 25 items, there was 100% agreement between all raters and the original ratings given by one rater on 15 patients. On the other 13 items, the proportion of agreement between all raters and the original rater ranged between 83% and 99%.

Validity

Criterion:
Concurrent:
Cooke, McKenna, Fleming, Darnell (2006b) examined the concurrent validityTo validate a new measure, the results of the measure are compared to the results of the gold standard obtained at approximately the same point in time (concurrently), so they both reflect the same construct. This approach is useful in situations when a new or untested tool is potentially more efficient, easier to administer, more practical, or safer than another more established method and is being proposed as an alternative instrument. See also "gold standard."
of the OT-APST in 208 patients with strokeAlso called a "brain attack" and happens when brain cells die because of inadequate blood flow. 20% of cases are a hemorrhage in the brain caused by a rupture or leakage from a blood vessel. 80% of cases are also know as a "schemic stroke", or the formation of a blood clot in a vessel supplying blood to the brain. by comparing patient performance on the OT-APST with their performance on the Loewenstein Occupational Therapy Cognitive Assessment (LOTCA) and the LOTCA-Geriatric version (LOTCA-G). Somer’s d was used to calculate correlations between the measures. The OT-APST was found to have a poor to excellent correlationThe extent to which two or more variables are associated with one another. A correlation can be positive (as one variable increases, the other also increases - for example height and weight typically represent a positive correlation) or negative (as one variable increases, the other decreases - for example as the cost of gasoline goes higher, the number of miles driven decreases. There are a wide variety of methods for measuring correlation including: intraclass correlation coefficients (ICC), the Pearson product-moment correlation coefficient, and the Spearman rank-order correlation.
with the LOTCA (0.27-0.64) and with the LOTCA-G (0.25-0.80).

Construct:
Convergent:
Cooke, McKenna, Fleming, Darnell (2006a) examined the convergent validityA type of validity that is determined by hypothesizing and examining the overlap between two or more tests that presumably measure the same construct. In other words, convergent validity is used to evaluate the degree to which two or more measures that theoretically should be related to each other are, in fact, observed to be related to each other.
of the OT-APST by comparing the subscales of the OT-APST to the corresponding subscaleMany measurement instruments are multidimensional and are designed to measure more than one construct or more than one domain of a single construct. In such instances subscales can be constructed in which the various items from a scale are grouped into subscales. Although a subscale could consist of a single item, in most cases subscales consist of multiple individual items that have been combined into a composite score (National Multiple Sclerosis Society).
of the Loewenstein Occupational Therapy Cognitive Assessment (LOTCA) or the LOTCA-Geriatric version (LOTCA-G) using Spearman’s rho correlations. Statistically significant correlations were found between each subscaleMany measurement instruments are multidimensional and are designed to measure more than one construct or more than one domain of a single construct. In such instances subscales can be constructed in which the various items from a scale are grouped into subscales. Although a subscale could consist of a single item, in most cases subscales consist of multiple individual items that have been combined into a composite score (National Multiple Sclerosis Society).
of the OT-APST and the corresponding subscaleMany measurement instruments are multidimensional and are designed to measure more than one construct or more than one domain of a single construct. In such instances subscales can be constructed in which the various items from a scale are grouped into subscales. Although a subscale could consist of a single item, in most cases subscales consist of multiple individual items that have been combined into a composite score (National Multiple Sclerosis Society).
of the LOTCA or LOTCA-G. The highest correlations occurred for the subscales of Constructional skills and Neglect, with more moderate correlations occurring for subscales assessing Agnosia, Body scheme, and Apraxia. Correlations ranged from poor (0.33 for Apraxia) to excellent (0.80 for Constructional skills).

Similar to the study by Cooke et al. (2006a), Itzkovich, Elazar, Averbuch and Katz (2000) examined the convergent validityA type of validity that is determined by hypothesizing and examining the overlap between two or more tests that presumably measure the same construct. In other words, convergent validity is used to evaluate the degree to which two or more measures that theoretically should be related to each other are, in fact, observed to be related to each other.
of the OT-APST with the Loewenstein Occupational Therapy Cognitive Assessment (LOTCA) in 208 people with stroke who were younger than 70 years of age. Adequate to excellent correlations were found between the OT-APST and on five of the related subscales of the reference tool of the LOTCA (r = 0.36 to r = 0.70).

Elazar, Itzkovich , and Katz (1996) examined the convergent validityA type of validity that is determined by hypothesizing and examining the overlap between two or more tests that presumably measure the same construct. In other words, convergent validity is used to evaluate the degree to which two or more measures that theoretically should be related to each other are, in fact, observed to be related to each other.
of the OT-APST with the Loewenstein Occupational Therapy Cognitive Assessment-Geriatric (LOTCA-G) version for those 70 years and over and found adequate to excellent correlations between the performance of elderly patients with strokeAlso called a "brain attack" and happens when brain cells die because of inadequate blood flow. 20% of cases are a hemorrhage in the brain caused by a rupture or leakage from a blood vessel. 80% of cases are also know as a "schemic stroke", or the formation of a blood clot in a vessel supplying blood to the brain. on the OT-APST and on the LOTCA-G (r = 0.33 to r = 0.80).

Cooke, McKenna, Fleming, Darnell (2006a) examined whether the OT-APST correlated with the Functional Independence Measure (FIM). Significant correlations were observed between six of the seven OT-APST subscales and FIM motor scores. Spearman’s correlations ranged from poor to adequate (r = 0.26 to r = 0.41). Significant correlations were found between all seven OT-APST subscales and the FIM cognitive scores. Spearman’s correlations were adequate (r = 0.36 to r = 0.50). Significant negative correlations were also observed between the time taken by participants to complete the OT-APST and both FIM scores, indicating that more severe functional disability was associated with greater length of time to complete the OT-APST. Body scheme was the only OT-APST subscaleMany measurement instruments are multidimensional and are designed to measure more than one construct or more than one domain of a single construct. In such instances subscales can be constructed in which the various items from a scale are grouped into subscales. Although a subscale could consist of a single item, in most cases subscales consist of multiple individual items that have been combined into a composite score (National Multiple Sclerosis Society).
score not significantly correlated with FIM motor scores.

Known groups:
Cooke, McKenna, Fleming, Darnell (2006a) examined whether the OT-APST was able to discriminate between patients with stroke and healthy control participants. The patients with strokeAlso called a "brain attack" and happens when brain cells die because of inadequate blood flow. 20% of cases are a hemorrhage in the brain caused by a rupture or leakage from a blood vessel. 80% of cases are also know as a "schemic stroke", or the formation of a blood clot in a vessel supplying blood to the brain. performed significantly worse than the healthy participants on all 7 subscales of the OT-APST, and took significantly longer to complete the test. All t-tests and Mann-Whitney U tests comparing the two groups were significant at p < 0.001. The OT-APST was found to correctly predict membership of the healthy group for 94.1% of the healthy participants, and correctly predicted membership of the strokeAlso called a "brain attack" and happens when brain cells die because of inadequate blood flow. 20% of cases are a hemorrhage in the brain caused by a rupture or leakage from a blood vessel. 80% of cases are also know as a "schemic stroke", or the formation of a blood clot in a vessel supplying blood to the brain. participant group for 56.7% of participants with strokeAlso called a "brain attack" and happens when brain cells die because of inadequate blood flow. 20% of cases are a hemorrhage in the brain caused by a rupture or leakage from a blood vessel. 80% of cases are also know as a "schemic stroke", or the formation of a blood clot in a vessel supplying blood to the brain.. The inverse figures for these comparisons are that 5.9% of the healthy participants were predicted to be members of the strokeAlso called a "brain attack" and happens when brain cells die because of inadequate blood flow. 20% of cases are a hemorrhage in the brain caused by a rupture or leakage from a blood vessel. 80% of cases are also know as a "schemic stroke", or the formation of a blood clot in a vessel supplying blood to the brain. group (predicted to have perceptual impairments), and 43.3% of participants following strokeAlso called a "brain attack" and happens when brain cells die because of inadequate blood flow. 20% of cases are a hemorrhage in the brain caused by a rupture or leakage from a blood vessel. 80% of cases are also know as a "schemic stroke", or the formation of a blood clot in a vessel supplying blood to the brain. were predicted to be members of the healthy group (no perceptual impairments).

Responsiveness

Not applicable.

References

• Cooke, D. (1993). Development and standardization of an apraxia assessment and perceptual screening test for the elderly. In: Australian Association of Occupational Therapists 17th National Conference Proceedings, 1993.
• Cooke, D. M., McKenna, K., Fleming, J. (2005a). Development of a standardized occupational therapy screening tool for visual perception in adults. Scandinavian Journal of Occupational Therapy, 12, 59-71.
• Cooke, D. M., McKenna, K., Fleming, J., Darnell, R. (2005b). The reliability of the Occupational Therapy Adult Perceptual Screening Test (OT-APST). British Journal of Occupational Therapy, 68(11), 509-517.
• Cooke, D. M., McKenna, K., Fleming, J., Darnell, R. (2006a). Construct and ecological validity of the Occupational Therapy Adult Perceptual Screening Test (OT-APST). Scandinavian Journal of Occupational Therapy. 13, 49- 61.
• Cooke, D. M., McKenna, K., Fleming, J., Darnell, R. (2006b). Criterion validity of the Occupational Therapy Adult Perceptual Screening Test (OT-APST). Scandinavian Journal of Occupational Therapy. 13, 38-48.
• Cooke, D. M., McKenna, K., Fleming, J., Darnell, R. (2006c). Australian normative data for the Occupational Therapy Adult Perceptual Screening Test. Australian Occupational Therapy, 53, 325-336.
• Itzkovich, M., Elazar, B., Averbuch, S., Katz, N.(2000). LOTCA manual (2nd ed.). Pequannock, NJ: Maddak Inc.
• Elazar, B., Itzkovich, M., Katz, N. (1996).Geriatric version: Loewenstein Occupational Therapy Cognitive Assessment (LOTCA-G) battery. Pequannock, NJ: Maddak Inc.

See the measure

How to obtain the OT-APST?

The OT-APST Assessment Kit and forms can be purchased from OT Australia Qld by visiting the following website: http://www.functionforlife.com.au/.

Purpose

The Ontario Society of Occupational Therapists (OSOT) Perceptual Evaluation was designed to assist in the detection of perceptual impairment in adults who have experienced brain damage caused by traumatic brain injury or stroke. The OSOT assesses perceptual dysfunction in areas related to basic living skills. The measure is also used to determine the degree of impairment, to monitor change, and to measure the effects of treatment and/or spontaneous recovery. The OSOT has been standardized for use with individuals aged 40-69 years.

In-Depth Review

Purpose of the measure

The Ontario Society of Occupational Therapists (OSOT) Perceptual Evaluation was designed to assist in the detection of perceptual impairment in adults who have experienced brain damage caused by traumatic brain injury or strokeAlso called a "brain attack" and happens when brain cells die because of inadequate blood flow. 20% of cases are a hemorrhage in the brain caused by a rupture or leakage from a blood vessel. 80% of cases are also know as a "schemic stroke", or the formation of a blood clot in a vessel supplying blood to the brain.. The OSOT assesses perceptual dysfunction in areas related to basic living skills. The measure is also used to determine the degree of impairment, to monitor change, and to measure the effects of treatment and/or spontaneous recovery. The OSOT has been standardized for use with individuals aged 40-69 years.

Available versions

The OSOT was created in 1972, by a study group formed in Toronto to discuss perceptual dysfunction in adults with brain damage. However, Boys, Fisher, Holzberg, and Reid (1988) were the first to standardize the OSOT.

Features of the measure

Items:

The original OSOT:

This evaluation consists of 28 subtests that evaluate 6 domains:

(Source: Boys et al., 1988)

Note: All test items have been recoded into the 4-point format. Only the test item Tactile suppression, which falls under the Sensation domain, is scored in a bivariate form of either 4 = present or 1 = absent.

The revised OSOT:

This evaluation consists of 18 subtests that evaluate 6 domains:

• Sensation
• Scanning
• Apraxia
• Body awareness
• Spatial relations
• Visual agnosia

In order to give the patient precise instructions, the evaluator must state the instructions verbatim prior to administering the OSOT. These instructions can only be repeated once. The evaluator must record all patient responses before offering help.

Scoring:

The OSOT uses a 5-point Likert scaleLikert scaling is one type of response to items in a questionnaire or tool. For example, Likert scaling would have you rate an item such as "I am satisfied with the care I received" on a scale using a 1-to-5 response scale where:
• 1 = strongly disagree
• 2 = disagree
• 3 = undecided
• 4 = agree
• 5 = strongly agree
You will find various options and scaling methods for the number of response choices (1-to-7, 1-to-9, 0-to-4). Odd-numbered scales usually have a middle value that is labelled Neutral or Undecided. Some tools used forced-choice Likert scaling with an even number of responses and no middle neutral or undecided choice. for each of the subtests, ranging from 0 = an inability to do what is asked of the patient, to 4 = normal performance. The scores obtained for each task are added to establish a total score. In the original OSOT, the maximum score that can be obtained is 112. Below is a breakdown of the scores. Each interval corresponds to a degree of severity of the global perceptual impairment:

(Source: Boys et al., 1988)

In the revised OSOT, the maximum score that can be obtained is 72. Below is a breakdown of the scores. Each interval corresponds to a degree of severity of the global perceptual impairment:

(Source: Boys et al., 1991)

Time:

There is no information published regarding the time it takes to complete the original OSOT, but it is anticipated that it would take longer than the revised OSOT which takes approximately 90 minutes to complete (Tremblay, Savard, Casimiro, & Tremblay, 2004).

Subscales:

The OSOT has 6 subscales or ‘domains’: Sensation; Scanning; Apraxia; Body awareness; Spatial relations; Visual agnosia.

Equipment:

• Instruction manual
• Evaluation material
• Pencil
• Chronometer
• 5″x11″ piece of paper
• Subtests and equipment for each subtest (e.g. a clock, 6 circles out of various sized cardboard, etc).

Training:

The OSOT was created to be used by occupational therapists. An adequate understanding of the instructions and procedures is needed before using the OSOT.

Alternative forms of the OSOT

The revised version of the OSOT (Boys, Fisher, & Holzberg, 1991).

In the revised version of the OSOT, 10 subtests have been eliminated from the 28 found in the original version of the measure.

Client suitability

Can be used with:

• Patients with strokeAlso called a "brain attack" and happens when brain cells die because of inadequate blood flow. 20% of cases are a hemorrhage in the brain caused by a rupture or leakage from a blood vessel. 80% of cases are also know as a "schemic stroke", or the formation of a blood clot in a vessel supplying blood to the brain..

Should not be used with:

• The OSOT has not been examined for use for patients with An alternative test is the Motor-Free Visual Perception Test, which can sometimes be used to examine the presence of visual perception impairments in patients with expressive aphasiaAphasia is an acquired disorder caused by an injury to the brain and affects a person's ability to communicate. It is most often the result of stroke or head injury.
  An individual with aphasia may experience difficulty expressing themselves when speaking, difficulty understanding the speech of others, and difficulty reading and writing. Sadly, aphasia can mask a person's intelligence and ability to communicate feelings, thoughts and emotions. (The Aphasia Institute, Canada) if they are able to understand simple verbal or non-verbal instructions and the various subscaleMany measurement instruments are multidimensional and are designed to measure more than one construct or more than one domain of a single construct. In such instances subscales can be constructed in which the various items from a scale are grouped into subscales. Although a subscale could consist of a single item, in most cases subscales consist of multiple individual items that have been combined into a composite score (National Multiple Sclerosis Society).
  requirements.

In what languages is the measure available?

Validated in French (Desrosiers, Mercier, & Rochette, 1999).

Summary

Psychometric Properties

Overview

The OSOT has not been well studied. To our knowledge, the creators of the OSOT have personally gathered the majority of psychometric data that are currently published on the scale. The psychometric properties of the original version of the OSOT were based on a study by Boys et al. (1988) of 80 patients with brain damage (experienced a strokeAlso called a "brain attack" and happens when brain cells die because of inadequate blood flow. 20% of cases are a hemorrhage in the brain caused by a rupture or leakage from a blood vessel. 80% of cases are also know as a "schemic stroke", or the formation of a blood clot in a vessel supplying blood to the brain., tumor, normopressure hydrocephalus, or anoxia), and a group of 70 neurologically intact participants. The psychometric properties of the revised version of the OSOT were based on a study by Boys et al. in 1991.

Further investigation on the reliability, validityThe degree to which an assessment measures what it is supposed to measure.
, and sensitivitySensitivity refers to the probability that a diagnostic technique will detect a particular disease or condition when it does indeed exist in a patient (National Multiple Sclerosis Society). See also "Specificity."
of the OSOT is required with larger numbers of subjects. For the purposes of this review, we conducted a literature search to identify all relevant publications on the psychometric properties of the OSOT.

Reliability

Internal consistencyA method of measuring reliability . Internal consistency reflects the extent to which items of a test measure various aspects of the same characteristic and nothing else. Internal consistency coefficients can take on values from 0 to 1. Higher values represent higher levels of internal consistency.:
Original OSOT:
Boys et al. (1988) examined the internal consistencyA method of measuring reliability . Internal consistency reflects the extent to which items of a test measure various aspects of the same characteristic and nothing else. Internal consistency coefficients can take on values from 0 to 1. Higher values represent higher levels of internal consistency. of the original OSOT and reported alpha coefficients ranging from poor (Body Awareness – Parts recognition, alpha = 0.23) to excellent (Sensory Function – Localization, alpha = 0.95).

Revised OSOT:
Boys et al. (1991) examined the internal consistencyA method of measuring reliability . Internal consistency reflects the extent to which items of a test measure various aspects of the same characteristic and nothing else. Internal consistency coefficients can take on values from 0 to 1. Higher values represent higher levels of internal consistency. of the revised OSOT and reported that this version of the OSOT has an excellent internal consistencyA method of measuring reliability . Internal consistency reflects the extent to which items of a test measure various aspects of the same characteristic and nothing else. Internal consistency coefficients can take on values from 0 to 1. Higher values represent higher levels of internal consistency. (Cronbachs alpha = 0.90).

Inter-rater:
Original OSOT:
Boys et al. (1988) examined the inter-rater reliabilityA method of measuring reliability . Inter-rater reliability determines the extent to which two or more raters obtain the same result when using the same instrument to measure a concept.
of the OSOT by having both the attending therapist and one of the investigators score the performance of 46 patients independently, on separate score sheets. Agreement for this study was very high (93.1%) across items for all subjects.

Validity

Criterion:

Concurrent:
Boyd and Dawson (2000) examined the relationship between perceptual impairment and independence in basic and instrumental activitiesAs defined by the International Classification of Functioning, Disability and Health, activity is the performance of a task or action by an individual. Activity limitations are difficulties in performance of activities. These are also referred to as function.
of daily living in a sample of older adults living in an institution or in the community. In this study, the OSOT correlated adequately with the Physical Self-Maintenance Scale (PSMS) (Lawton, & Brody, 1969) (r = 0.44), the Instrumental ActivitiesAs defined by the International Classification of Functioning, Disability and Health, activity is the performance of a task or action by an individual. Activity limitations are difficulties in performance of activities. These are also referred to as function.
of Daily Living Scale (r = 0.44), and with the Mini-Mental State Evaluation (MMSE) (Folstein, Folstein, & McHugh, 1975) (r = 0.43). The results of this study suggest that perceptual impairment is related to activitiesAs defined by the International Classification of Functioning, Disability and Health, activity is the performance of a task or action by an individual. Activity limitations are difficulties in performance of activities. These are also referred to as function.
of daily living status.

Construct:

Boys et al. (1988) reported that the moderate correlations observed between scores obtained for each of the 6 domains of the original OSOT demonstrates that each domain measures different concepts, which together give a global perceptual deficit score.

Known groups:
Both the original OSOT and the revised OSOT have been shown to discriminate between patients with acquired brain injury and healthy controls (Boys et al., 1991; Boys et al.,1988). When the performance of patients and control participants were compared in the study by Boys et al. (1988), statistically significant differences were observed for all tests except for Ideational Apraxia.

Sensitivity and specificity:

Boys et al. (1988) reported that the total score of the original version of the OSOT can differentiate between individuals with neurological impairment from neurologically normal control participants. At a total score cutoff of 110, the OSOT can differentiate between individuals with functional impairment and a control group without neurological impairment with a sensitivitySensitivity refers to the probability that a diagnostic technique will detect a particular disease or condition when it does indeed exist in a patient (National Multiple Sclerosis Society). See also "Specificity."
of 100% and a specificitySpecificity refers to the probability that a diagnostic technique will indicate a negative test result when the condition is absent (true negative).
of only 40%. At a cutoff of 100, the sensitivitySensitivity refers to the probability that a diagnostic technique will detect a particular disease or condition when it does indeed exist in a patient (National Multiple Sclerosis Society). See also "Specificity."
was 63.7% and the specificitySpecificity refers to the probability that a diagnostic technique will indicate a negative test result when the condition is absent (true negative).
was 100%.

Boys et al. (1991) reported that the total score of the revised version of the OSOT can also differentiate between individuals with brain damage from neurologically normal control participants. The sensitivitySensitivity refers to the probability that a diagnostic technique will detect a particular disease or condition when it does indeed exist in a patient (National Multiple Sclerosis Society). See also "Specificity."
was 100% with a cutoff score of 70 and over, and of 58% with a cutoff of 60. The specificitySpecificity refers to the probability that a diagnostic technique will indicate a negative test result when the condition is absent (true negative).
was 40% with a cutoff score of 70 and under, and 100% with a cutoff of 60.

References

• Boyd, A., Dawson, D. R. (2000). The relationship between perceptual impairment and self-care status in a sample of elderly persons. Physical & Occupational Therapy in Geriatrics, 17(4), 1-16.
• Boys, M., Fisher, P., & Holzberg, C. (1991). The OSOT Perceptual Evaluation Manual: Revised. Scarborough, Ont.: Nelson Canada.
• Boys, M., Fisher, P., Holzberg, C., & Reid, D. (1988). The OSOT Perceptual Evaluation: A research perspective. American Journal of Occupational Therapy. 42, 92-98.
• Desrosiers, J.,Mercier, L.,Rochette, A. (1999).Test-retest and inter-rater reliability of the French version of the Ontario Society of Occupational Therapy (OSOT)Perceptual Evaluation. Can J Occup Therapy, 66(3), 134 -139.
• Folstein, M., Folstein, S., McHugh, P. (1975). Mini-mental State: A practical method for grading the cognitive state of patients for the clinician. Journal of Psychiatric Research, 12,189-198.
• Lawton, M. P., Brody, E. M. (1969). Assessment of older people: self-maintaining and instrumental activities of daily living. Gerontologist, 9, 179-186.
• Temblay, L. E., Savard, J., Casimiro, L., Tremblay, M. (2004). Répertoire des Outils d’Évaluation en Français pour la Réadaptation (pp406-408). Ottawa, ON: Regroupement des intervenantes et intervenants francophones en santé et en services sociaux de l’Ontario: Université d’Ottawa: CFORP.

See the measure

The OSOT can be purchased from the publisher:

Publisher address:
Nelson, A Thomson Company
1120 Birchmount Road,
Toronto, Ontario M1K 5G4, Canada
Telephone: 416-752-9448 or 1 800 268-2222
Fax: 416-752-8101 or 1 800 430-4445
E-mail: inquire@nelson.com
Website: http://www.assess.nelson.com/pdf/assessmentcatalogue/cn-19.pdf

Cost: (price is subject to change)
Perceptual evaluation kit (version 2, with English manual): $859
English manual: $75
French manual: $31.80