Cambridge Cognition Examination (CAMCOG)

Purpose

The Cambridge Cognition Examination (CAMCOG) is the cognitive and self-contained part of the Cambridge Examination for Mental Disorders of the Elderly (CAMDEX). The CAMCOG is a standardized instrument used to measure the extent of dementia, and to assess the level of cognitive impairment. The measure assesses orientation, language, memory, praxis, attention, abstract thinking, perception and calculation (Roth, Tym, Mountjoy, Huppert, Hendrie, Verma, et al., 1986).

In-Depth Review

Purpose of the measure

The Cambridge Cognition Examination (CAMCOG) is the cognitive and self-contained part of the Cambridge Examination for Mental Disorders of the Elderly (CAMDEX). The CAMCOG is a standardized instrument used to measure the extent of dementia, and to assess the level of cognitive impairment. The measure assesses orientation, language, memory, praxis, attention, abstract thinking, perception and calculation (Roth, Tym, Mountjoy, Huppert, Hendrie, Verma, et al., 1986).

Available versions

The CAMCOG was developed in 1986 by Roth, Tym, Mountjov, Huppert, Hendrie, Verma and Godddard. In 1999, Roth, Huppert, Mountjoy and Tym reviewed it and then published the CAMCOG-R. In 2000, de Koning, Dippel, van Kooten and Koudstall shortened the 67 items of the CAMCOG to 25 items, known as the Rotterdam CAMCOG (R-CAMCOG).

Features of the measure

Items:

The CAMCOG consists of 67 items, including the 19 items from the Mini Mental State Examination (MMSE) (Folstein, Folstein, & McHugh, 1975). It is divided into 8 subscales: orientation, language (comprehension and expression), memory (remote, recent and learning), attention, praxis, calculation, abstraction and perception (de Koning, van Kooten, Dippel, van Harskramp, Grobbee, Kluft, et al. 1998).

The orientation 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).
is comprised of 10 items taken from the MMSE. In the language 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).
, comprehension is assessed through nonverbal and verbal responses to spoken and written questions, and expression is assessed through tests of naming, repetition, fluency and definitions. The memory 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).
assesses remote memory (famous events and people), recent memory (news items, prime minister, etc.), and learning (the recall and recognition of non-verbal and pictorial information learned incidentally as well as intentionally). Attention is assessed by serial sevens and counting backwards from 20. Praxis is assessed by copying, drawing, and writing as well as carrying out instructions. In the calculation 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 client is asked to perform an addition and a subtraction question involving money. For the abstraction 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 client is asked about similarities between an apple and a banana, a shirt and a dress, a chair and a table, and a plant and an animal. In the perception 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 client is asked to identify photographs of famous people and familiar objects from unusual angles, in addition to the tactile recognition of coins (Huppert, Jorm, Brayne, Girling, Barkley, Bearsdall et al., 1996).

The number of scored items 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).
is as follows (de Koning et al., 1998; Huppert et al., 1996).

CAMCOG subscales	Number of scored items
Orientation	10
Language Comprehension Expression	9 8
Memory Learning Recent Remote	3 4 6
Concentration	2
Praxis	8
Calculation	2
Perception	3
Abstraction	4
Number of scored items	59

Items related to 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) or upper extremity paresis may not be tested in all clients and depend on 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. More severity.

Detailed administration guidelines are in the CAMCOG manual that can be obtained from the Cambridge University Department of Psychiatry.

Scoring:

The CAMCOG total score ranges from 0 to 107. Scores lower than 80 are considered indicative of dementia (de Koning et al., 1998; Roth et al., 1986). Among the 67 CAMCOG items, 39 are scored as ‘right’ or ‘wrong’; 11 are scored on a 3-point scale with ‘wrong’, ‘right to a certain degree’ or ‘completely right’ as response options; 9 items encompass questions or commands, and the score for each item is the sum of the correct answers; and finally 8 items are not scored. Five of the non-scored items are from the MMSE and they are not included in the total score because they are assessed in more detail by other CAMCOG items. The remaining 3 items are optional during the examination (de Koning, Dippel, van Kooten, & Koudstall, 2000; Huppert et al.,1996).

The maximum score per 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).
is as follows (Huppert et al., 1996):

CAMCOG subscales	Number of scored items
Orientation	10
Language Comprehension Expression	9 21
Memory Learning Recent Remote	17 4 6
Concentration	4
Praxis	12
Calculation	5
Perception	11
Abstraction	8
Maximum Total Score	107

Time:

The CAMCOG takes 20 to 30 to administer and the R-CAMCOG takes 10 to 15 minutes to administer (de Koning et al, 1998; de Koning et al., 2000; Huppert et al., 1996).

Subscales:

The CAMCOG is comprised of 8 subscales:

• Orientation
• Language: subdivided into comprehensive and expressive language
• Memory: subdivided into remote, recent and learning memory
• Attention
• Praxis
• Calculation
• Abstraction
• Perception

Equipment:

The CAMCOG requires no specialized equipment. Only the test and a pencil are needed to complete the assessment.

The CAMCOG requires specialized equipment that are enclosed within its manual. The manual can be purchased from the Cambridge University Department of Psychiatry.

Alternative forms of the CAMCOG

• Revised CAMCOG (CAMCOG-R): Published in 1999 by Roth, Huppert, Mountjoy and Tym, the CAMCOG-R improved the ability of the measure to detect certain types of dementia and to make clinical diagnoses based on the ICD-10 and DSM-IV. This version includes updated items from the remote memory 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).
  and the addition of items to assess executive function (Leeds, Meara, Woods & Hobson, 2001; Roth, Huppert, Mountjoy & Tym, 1999).
• Rotterdam CAMCOG (R-CAMCOG): Published in 2000, the R-CAMCOG is a shortened version of the CAMCOG with 25 items. It takes 10 to 15 minutes to administer and is as accurate as the CAMCOG in screeningTesting for disease in people without symptoms.
  for post-stroke dementia (de Koning et al., 2000).
• General Practitioner Assessment of Cognition (GPCOG): Published in 2002 to be used in primary care settings, the GPCOG contains 9 cognitive and 6 informant items that were derived from the Cambridge Cognitive Examination, the Psychogeriatric Assessment Scale (Jorm, Mackinnon, Henderson, Scott, Christensen, Korten et al. 1995) and 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 (Lawton & Brody, 1969). The GPCOG takes 4 to 5 minutes to administer and appears to have a diagnostic accuracy similar to the Mini-Mental State Examination (Folstein, Folstein, & McHugh, 1975) in detecting dementia (Brodaty, Pond, Kemp, Luscombe, Harding, Berman et al., 2002).

Client suitability

Can be used with:

• Clients 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. More
• Clients with different types of dementia

Should not be used with:

• The CAMCOG should not be used with clients with severe cognitive impairment.
• Items related to 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) and upper extremity paresis might not be tested on all clients and appropriate use depends on 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. More severity.

In what languages is the measure available?

English and Dutch (de Koning et al., 2000).

Summary

What does the tool measure?	The CAMCOG is a standardized instrument for diagnosis and grading of dementia.
What types of clients can the tool be used for?	The CAMCOG can be used with, but is not limited to clients 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. More.
Is this a screeningTesting for disease in people without symptoms. or assessment tool?	Assessment
Time to administer	The CAMCOG takes 20 to 30 minutes to administer.
Versions	Revised CAMCOG (CAMCOG-R); Rotterdam-CAMCOG (R-CAMCOG); General Practitioner Assessment of Cognition (GPCOG)
Other Languages	English; Dutch
Measurement Properties
ReliabilityReliability can be defined in a variety of ways. It is generally understood to be the extent to which a measure is stable or consistent and produces similar results when administered repeatedly. A more technical definition of reliability is that it is the proportion of “true” variation in scores derived from a particular measure. The total variation in any given score may be thought of as consisting of true variation (the variation of interest) and error variation (which includes random error as well as systematic error). True variation is that variation which actually reflects differences in the construct under study, e.g., the actual severity of neurological impairment. Random error refers to “noise” in the scores due to chance factors, e.g., a loud noise distracts a patient thus affecting his performance, which, in turn, affects the score. Systematic error refers to bias that influences scores in a specific direction in a fairly consistent way, e.g., one neurologist in a group tends to rate all patients as being more disabled than do other neurologists in the group. There are many variations on the measurement of reliability including alternate-forms, internal consistency , inter-rater agreement , intra-rater agreement , and test-retest .	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. More: No studies have 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. More of the CAMCOG in clients 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. More.
ValidityThe degree to which an assessment measures what it is supposed to measure.	Content: – No studies have examined the content validityRefers to the extent to which a measure represents all aspects of a given social concept. Example: A depression scale may lack content validity if it only assesses the affective dimension of depression but fails to take into account the behavioral dimension. of the CAMCOG in clients 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. More. – One study examined the content validityRefers to the extent to which a measure represents all aspects of a given social concept. Example: A depression scale may lack content validity if it only assesses the affective dimension of depression but fails to take into account the behavioral dimension. of the R-CAMCOG by reporting the steps for generating the shortened version of the CAMCOG. Criterion: Concurrent: No studies have 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 CAMCOG. Predictive: Six studies 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 CAMCOG and reported that the CAMCOG can be predicted by age, the R-CAMCOG, the Mini-Mental State Examination and cognitive and emotional impairments. Additionally, the CAMCOG was an excellent predictor of dementia 3 to 9 months post-stroke. However, the CAMCOG was not able to predict QOL in clients 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. More and is not predicted by the Functional Independence Measure. Construct: Convergent: – One study 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 CAMCOG in clients 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. More and reported excellent correlations between the CAMCOG and the R-CAMCOG and the Mini-Mental State Examination shortly after and 1 year post-stroke. Correlations between the CAMCOG and the Functional Independence Measure range from adequate 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. More to poor at 1 year post-stroke. – One study 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 CAMCOG-R and reported excellent correlations between the CAMCOG-R and the Raven Test and the Weigl Test and poor correlations between the CAMCOG-R and the Geriatric DepressionIllness involving the body, mood, and thoughts, that affects the way a person eats and sleeps, the way one feels about oneself, and the way one thinks about things. A depressive disorder is not the same as a passing blue mood or a sign of personal weakness or a condition that can be wished away. People with a depressive disease cannot merely “pull themselves together” and get better. Without treatment, symptoms can last for weeks, months, or years. Appropriate treatment, however, can help most people with depression. Scale and the Barthel Index 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. . Known Groups: Two studies using student t-test examined known groups validityKnown groups validity is a form of construct validation in which the validity is determined by the degree to which an instrument can demonstate different scores for groups know to vary on the variables being measured. of the CAMCOG and reported that the CAMCOG is able to distinguish between clients with or without dementia as well as 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) severity in clients 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. More.
Floor and 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.” More	One study examined the floor / ceiling effects of the CAMCOG in clients 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. More and reported that 14 items showed ceiling effects but no floor effects
Does the tool detect change in patients?	– No studies have examined the responsivenessThe ability of an instrument to detect clinically important change over time. of the CAMCOG in clients 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. More. – One study examined the responsivenessThe ability of an instrument to detect clinically important change over time. of the CAMCOG-R and reported that at follow-up scores changes were all statistically significant (p<0.01).
Acceptability	Items related to 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) and upper extremity paresis might not be tested on all clients due to 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. More severity.
Feasibility	The instructions for administration and coding must be followed closely (Ruchinskas and Curyto, 2003).
How to obtain the tool?	The CAMCOG can be obtained by purchasing the entire CAMDEX from the Cambridge University Department of Psychiatry

Psychometric Properties

Overview

We conducted a literature search to identify all relevant publications on the psychometric properties of the Cambridge Cognition Examination (CAMCOG) in individuals 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. More. We identified 6 studies on the CAMCOG, 1 on the CAMCOG-R and 1 on the R-CAMCOG.

Floor/Ceiling Effects

de Koning, Dippel, van Kooten and Koudstaal (2000) analyzed the floor and ceiling effects of the CAMCOG in 300 clients 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. More. 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." More was found in 2 out of 10 orientation items, 8 out 17 language items, 2 out of 13 memory items, 1 out of 8 praxis items, and 1 out of 3 perception items, with more than 20% of participants scoring the maximum score. No floor effectThe floor effect is when data cannot take on a value lower than some particular number. Thus, it represents a subsample for whom clinical decline may not register as a change in score, even if there is worsening of function/behavior etc. because there are no items or scaling within the test that measure decline from the lowest possible score. See also "ceiling effect."
was observed in the CAMCOG.

Reliability

No studies have examined the reliabilityReliability can be defined in a variety of ways. It is generally understood to be the extent to which a measure is stable or consistent and produces similar results when administered repeatedly. A more technical definition of reliability is that it is the proportion of "true" variation in scores derived from a particular measure. The total variation in any given score may be thought of as consisting of true variation (the variation of interest) and error variation (which includes random error as well as systematic error). True variation is that variation which actually reflects differences in the construct under study, e.g., the actual severity of neurological impairment. Random error refers to "noise" in the scores due to chance factors, e.g., a loud noise distracts a patient thus affecting his performance, which, in turn, affects the score. Systematic error refers to bias that influences scores in a specific direction in a fairly consistent way, e.g., one neurologist in a group tends to rate all patients as being more disabled than do other neurologists in the group. There are many variations on the measurement of reliability including alternate-forms, internal consistency , inter-rater agreement , intra-rater agreement , and test-retest .
of the CAMCOG in clients 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. More.

Validity

Content:

No studies have examined the content validityRefers to the extent to which a measure represents all aspects of a given social concept. Example: A depression scale may lack content validity if it only assesses the affective dimension of depression but fails to take into account the behavioral dimension.
of the CAMCOG in clients 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. More.

de Koning et al. (2000) analyzed CAMCOG scores from 300 clients 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. More and reduced the 59 items of the CAMCOG to the 25 items of the R-CAMCOG. Initially, item reduction was performed by removing 14 items with ceiling effects on the CAMCOG. Next, the language, attention, praxis, and calculation subscales were eliminated due to their low diagnostic accuracy. Finally, items with a very low or very high inter-item 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.
were removed.

Criterion:

Concurrent:
No studies have 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 CAMCOG in clients 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. More.

Predictive:
Kwa, Limburg, Voogel, Teunisse, Derix and Hijdra (1996a) examined whether age, educational level, side and volume of the infarct, 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) severity, and motor function predicted CAMCOG scores at 3 months 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. More in 129 clients. A cut-off of 80 was used to discriminate between normal and abnormal cognitive function. Based on regression analysis with these above-mentioned variables included, age appeared to be the best predictor of CAMCOG scores 3 months post-stroke.
Note: The timeline for the baseline measurements were not reported in the study.

Kwa, Limburg and de Haan (1996b) verified the ability of the CAMCOG, the Rankin Scale (Rankin, 1957), the Barthel Index (Mahoney & Barthel, 1965), the Motricity Index (Colin & Wade, 1990), 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) severity, age, educational level, volume and side of the infarct to predict quality of life in 97 clients 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. More. Linear regression analysis indicated that quality of life is best predicted by the Rankin Scale, volume of infarct and 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) severity.
Note: The timeline for all the measurements were not reported in the study.

de Koning, van kooten, Dippel, van Harskamp, Grobbee, Kluft, et al. (1998) analyzed the ability of the CAMCOG and the Mini-Mental State Examination (MMSE – Folstein, Folstein, & McHugh, 1975) measured shortly 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. More to predict dementia measured 3 to 9 months later in 300 clients 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. More. 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.
was calculated by use of c-statistics to calculate the area under the Receiver Operating Characteristic (ROC) curve. The ability of the CAMCOG (AUC = 0.95) and the MMSE (AUC = 0.90) to predict dementia 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. More were both considered excellent. These results suggest that the percentage of patients correctly classified according to their dementia level at 3 to 9 months post-stroke is only slightly higher when using the CAMCOG over the MMSE.

de Koning et al. (2000) examined whether the CAMCOG and the R-CAMCOG, measured at hospital admission predicted dementia at 3 to 9 months post-stroke in 300 clients. 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.
, as calculated using c-statistics to estimate the area under the Receiver Operating Characteristic (ROC) curve, were all excellent for the CAMCOG (AUC = 0.95) and the CAMCOG-R (AUC = 0.95). These results suggest that the percentage of patients correctly classified according to their dementia level at 3 to 9 months post-stroke is the same when using the CAMCOG and the R-CAMCOG. Additionally, when using a cut-off of 77 for the CAMCOG and 33 for the R-CAMCOG, both measures showed 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 91% 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 88% and 90%, respectively.

van Heugten, Rasquin, Winkens, Beusmans, and Verhey (2007) estimated the ability of a checklist of cognitive and emotional impairments measured 6 months post-stroke to predict the CAMCOG and the Mini-Mental State Examination (MMSE – Folstein, Folstein, & McHugh, 1975) scores at 12 months in 69 clients. Regression analysis showed that cognitive and emotional impairments explained 31% of the variance on the MMSE and 22% of the variance on the CAMCOG. These results suggest that cognitive and emotional impairments were able to predict the scores of both measures.

Winkel-Witlox, Post, Visser-Meily, and Lindeman (2008) analyzed the ability of the R-CAMCOG, the Mini-Mental State Examination (MMSE – Folstein, Folstein, & McHugh, 1975) and the Functional Independence Measure (FIM – Keith, Granger, Hamilton, & Sherwin, 1987) to predict the CAMCOG in 169 clients. All four outcomes measures were collected shortly after and 1 year post-stroke. Regression analysis showed that 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. More the R-CAMCOG explained 83% of variance on the CAMCOG, the MMSE explained 53% and the FIM 11%. At 1 year post-stroke the R-CAMCOG explained 82% of variance on the CAMCOG, the MMSE explained 57% and the FIM only 04%. These results suggest that the R-CAMCOG is the best predictor of the CAMCOG among these independent variables.

Construct:

Convergent/Discriminant:
Winkel-Witlox et al. (2008) 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 CAMCOG by comparing it to R-CAMCOG, the Mini-Mental State Examination (MMSE – Folstein, Folstein, & McHugh, 1975) and the Functional Independence Measure (FIM – Keith, Granger, Hamilton, & Sherwin, 1987) in 169 clients 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. More. Shortly after and at 1 year post-stroke correlations between the CAMCOG and the R-CAMCOG and the MMSE were all excellent (rho1 = 0.92; 066, rho2 = 0.92; 069, respectively). Correlations between the CAMCOG and the FIM was adequate shortly 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. More (rho1 = 0.35) and poor after 1 year (rho2 = 0.27).

Leeds, Meara, Woods and Hobson (2001) analyzed 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 CAMCOG-R by comparing it to the Raven Test (Raven, 1982), the Weigl Test (Grewal, Haward, & Davies, 1986), the Geriatric DepressionIllness involving the body, mood, and thoughts, that affects the way a person eats and sleeps, the way one feels about oneself, and the way one thinks about things. A depressive disorder is not the same as a passing blue mood or a sign of personal weakness or a condition that can be wished away. People with a depressive disease cannot merely “pull themselves together” and get better. Without treatment, symptoms can last for weeks, months, or years. Appropriate treatment, however, can help most people with depression.
Scale (Sheikh & Yesavage, 1986) and the Barthel Index (Mahoney & Barthel, 1965) in 83 clients 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. More. Correlations as calculated using Pearson correlations were excellent between the CAMCOG-R and the Raven Test (r = 0.75) and the Weigl Test (r = 0.70). Correlations between the CAMCOG-R and the Geriatric DepressionIllness involving the body, mood, and thoughts, that affects the way a person eats and sleeps, the way one feels about oneself, and the way one thinks about things. A depressive disorder is not the same as a passing blue mood or a sign of personal weakness or a condition that can be wished away. People with a depressive disease cannot merely “pull themselves together” and get better. Without treatment, symptoms can last for weeks, months, or years. Appropriate treatment, however, can help most people with depression.
Scale (r = -0.30) and the Barthel Index (r = 0.20) were poor.

Known groups.
de Koning et al. (1998) analyzed whether the CAMCOG is able to distinguish between individuals with dementia from those without dementia in 300 clients 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. More. Known groups validityKnown groups validity is a form of construct validation in which the validity is determined by the degree to which an instrument can demonstate different scores for groups know to vary on the variables being measured.
, as calculated using student t-test, showed that the CAMCOG was able to discriminate clients with dementia from those without dementia. These results demonstrated that clients with dementia have statistically significant lower scores on the CAMCOG.

Kwa et al. (1996a) verified the ability of the CAMCOG to discriminate between clients without 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) and those with severe 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) in 129 clients 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. More. Known groups validityKnown groups validity is a form of construct validation in which the validity is determined by the degree to which an instrument can demonstate different scores for groups know to vary on the variables being measured.
, as calculated using the student t-test, showed that the CAMCOG was able to differentiate between 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) severity.

Responsiveness

No studies have examined the responsivenessThe ability of an instrument to detect clinically important change over time.
of the CAMCOG in clients 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. More.

Leeds et al. (2001) examined the responsivenessThe ability of an instrument to detect clinically important change over time.
of the CAMCOG-R in 83 clients 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. More. Participants were assessed at baseline and 63 days later. At follow-up, changes on the CAMCOG-R scores were all statistically significant (p<0.01). These results suggest that the CAMCOG-R appears sensitive to change in cognitive status of clients 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. More.

References

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• Collin, C. & Wade, D. (1990). Assessing motor impairment after stroke: A pilot reliability study. J Neurology Neurosurg Psychiatry, 53, 576-579.
• de Koning, I., Dippel, D.W.J., van Kooten, F. & Koudstaal, P.J. (2000). A short screening instrument for poststroke dementia: The R-CAMCOG. Stroke, 31, 1502-1508.
• de Koning, I., van Kooten, F., Dippel, D.W.J., van Harskamp, F., Grobbee, D.E., Kluft, C. & Koudstaal, P.J. (1998). The CAMCOG: A useful screening instrument for dementia in stroke patients. Stroke, 29, 2080-2086.
• Folstein, M.F., Folstein, S. E. & McHugh, P. R. (1975). “Mini-mental state”. A practical method for grading the cognitive state of patients for the clinician. J Psychiatr Res, 12(3), 189-198.
• Grewal, B., Haward, L. & Davies, I. (1986). Color and form stimulus values in a test of dementia. IRCS Med Sci, 14, 693-694.
• Huppert, F.A., Jorm, A.F., Brayne, C., Girling, D.M., Barkeley, C., Bearsdall, et al. (1996). Psychometric properties of the CAMCOG and its efficacy in the diagnosis of dementia. Aging, Neuropsychology, and Cognition, 3, 201-214.
• Jorm, A.F., Mackinnon, A.J., Henderson, A.S., Scott, H., Christensen, H., Korten, A.E., et al. (1995). The Psychogeriatric Assessment Scales: A multidimensional alternative to categorical diagnoses of dementia and depression in the elderly. Psychol Med, 25, 447-460.
• Keith, R.A., Granger, C.V., Hamilton, B.B., & Sherwin, F.S. (1987). The functional independence measure: A new tool for rehabilitation. Adv Clin Rehabil, 1, 6-18.
• Kwa, V.I.H., Limburg, M. & de Haan, R.J. (1996b). The role of cognitive impairment in the quality of life after ischaemic stroke. J Neurol, 243, 599-604.
• Kwa, V.I.H., Limburg, M., Voogel, A.J., Teunisse, S., Derix, M.M.A. & Hijdra, A. (1996a). Feasibility of cognitive screening of patients with ischaemic stroke using the CAMCOG: a hospital based study. J Neurol, 243, 405-409.
• Lawton, M.P. & Brody, E.M. (1969). Assessment of older people: Self-maintaining and instrumental activities of daily living. Gerontologist, 9, 179-186.
• Leeds, L., Meare, R.J., Woods, R. & Hobson, J.P. (2001). A comparison of the new executive functioning domains of the CAMCOG-R with existing tests of executive function in elderly stroke survivors. Age and Ageing, 30, 251-254.
• Mahoney, F. & Barthel, D. (1965). Functional evaluation: The Barthel Index. MD State J, 14, 61-65.
• Rankin, J. (1957). Cerebral vascular accidents in patients over the age of 60. Scott Med J, 2, 200-215.
• Raven, J.C. (1982). Revised manual for Raven’s Coloured Progressive Matrices. Windsor, UK: NFER-Nelson.
• Roth, M., Huppert, F., Mountjoy, C., & Tym, E. (1999). The Cambridge Examination for Mental Disorders of the Elderly – Revised. Cambridge: Cambridge University Press.
• Roth, M., Tym, E., Mountjoy, C., Huppert, F.A., Hendrie, H., Verma, S. et al. (1986). CAMDEX: A standardized instrument for the diagnosis of mental disorder in the elderly with special reference to the early detection of dementia. British Journal of Psychiatry, 149, 698-709.
• Ruchinskas, R.A. & Curyto, K. (2003). Cognitive screening in geriatric rehabilitation. Rehabilitation Psychology, 48(1), 14-22.
• Sheikh, J.A. & Yesavage, J.A. (1986). Geriatric depression scale (GDS): Recent findings and development of a shorter version. Clinical Gerontologist, 5, 165-172.
• Winkel-Witlox, A.C.M.Te, Post, M.W.M., Visser-Meily, J.M.A., & Linderman, E. (2008). Efficient screening of cognitive dysfunction in stroke patients: Comparison between the CAMCOG and the R-CAMCOG, Mini-Mental State Examination and Functional Independence Measure-cognition score. Disability and Rehabilitation, 30(18), 1386-1391.
• van Heugten, C., Rasquin, S., Winkens, I., Beusmans, G., & Verhey, F. (2007). Checklist for cognitive and emotional consequences following stroke (CLCE-24): Development, usability and quality of the self-report version. Clinical Neurology and Neurosurgery, 109, 257-262.

See the measure

How to obtain the CAMCOG

The CAMCOG can be obtained by purchasing the entire CAMDEX from the Cambridge University Department of Psychiatry.