Comb and Razor Test

Purpose

The Comb and Razor Test screens for unilateral spatial neglect (USN) in the client’s personal space by assessing their performance in functional 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.
, such as using a comb or applying makeup.

In-Depth Review

Purpose of the measure

The Comb and Razor Test screens for unilateral spatial neglect (USN) in the client’s personal space by assessing their performance in functional 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.
, such as using a comb or applying makeup.

Available versions

The Comb and Razor Test was published by Beschin and Robertson in 1997 and was developed from a test by Zoccolotti and Judica (1991) (Beschin & Robertson, 1997), which comprised of three tasks: hair combing, pretend shaving (men) or facial compact use (women) and putting on glasses.

Features of the measure

Items:
There are no actual items for the Comb and Razor Test. The patient is asked to demonstrate the use of two common objects for 30 seconds each: 1. comb and 2. razor or powder compact case. Each object is placed at the patient’s midline.

Comb (Males and Females)

• Examiner sits opposite to the patient and holds the comb up saying: “I would like you to comb your hair, and continue combing until I tell you to stop. Do you understand that? O.K., now begin”.
• Examiner activates the stopwatch as soon as the patient takes the comb.
• Examiner observes and records the number of moves on the left side and right side of the head. Any moves that are difficult to categorize are classified as ambiguous.
• At the end of 30 seconds, the examiner asks the patient to stop, and takes the comb from him or her.

Razor (Males)

• Examiner sits opposite to the patient and holds the razor up saying: “I am going to give you a razor, and I want you to pretend that you are shaving (razor with shield). I want you to continue shaving until I say stop. Do you understand?”
• Examiner activates the stopwatch as soon as the patient takes the razor.
• Examiner observes and records the number of moves on the left side and right side of the head. Any moves that are difficult to categorize are classified as ambiguous.
• At the end of 30 seconds, the examiner asks the patient to stop, and takes the razor from him.

Powder Compact Case (Females)

• Examiner sits opposite to the patient and holds the open powder compact case up saying: “I am going to give you a powder compact case and I want you to pretend that you are putting powder on your face. I want you to continue putting powder until I say stop. Do you understand?”
• Examiner activates the stopwatch as soon as the patient takes the powder compact case.
• Examiner observes and records the number of touches on the left side and right side of the head. Any touches that are difficult to categorize are classified as ambiguous.
• At the end of 30 seconds, the examiner asks the patient to stop, and takes the powder compact case from her.

Scoring:
There are two scoring methods available, the original Beschin and Robertson (1997) method and the preferred reformulated McIntosh et al. (2000) scoring method:

Beschin and Robertson (1997) scoring method:

The number of moves with the razor, comb or powder compact that are made to the left, right or ambiguously are recorded to calculate an average percentage for all three categories.

% left = (left moves) / (left + ambiguous + right moves)

The % left is calculated for the comb and razor/powder compact case, and the scores are combined in the formula below as the index for left personal neglect:

(razor/compact case % left) + (comb % left) / 2

A score < 0.35 indicates the presence of left personal neglect. A score > 0.35 indicates the absence of left personal neglect.

McIntosh et al. (2000) scoring method:

McIntosh, Brodie, Beschin, and Robertson (2000) developed a reformulated scoring method for the Comb and Razor Test, which is considered the preferred method:

% bias = (left – right moves) / (left + ambiguous + right moves)

The % bias formula yields a score between -1 (total left neglect) and +1 (total right neglect), with symmetrical performance at 0.

Time:
The Comb and Razor Test takes around 5 minutes to complete.

Training:
No training required.

Subscales:
None.

Equipment:

• One comb
• One razor with shield
• One powder compact case
• Stopwatch

Alternative forms of the Comb and Razor Test

Reformulated Comb and Razor Test (McIntosh, Brodie, Beschin, & Robertson, 2000).

McIntosh et al. (2000) examined a new method for scoring the Comb and Razor Test, which characterizes personal neglect as a lateral bias of behavior without further assumptions about the direction of bias, rather than as a lateralized deficit. The original % left formula of Beschin and Robertson (1997) (see scoring), characterizes personal grooming behavior according to the proportion of the total activity that is directed to the left side of the body. Conversely, the proposed %bias formula of McIntosh et al. (2000) yields a score between -1 (total left neglect) and +1 (total right neglect), with symmetrical performance at 0. The reformulated version of the Comb and Razor Test was able to discriminate between 17 right brain damaged 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. More and extra personal neglect from 14 right brain damaged 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. More without extra personal neglect as well as both of these groups from left brain damaged 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. More and healthy controls. This version was also found to be more sensitive to the behavioral abnormalities of patients with brain damage than the original. In the %left index, 11 patients performed below cut-off, however with the %bias cut-off, 20 patients performed below cut-off. Further, all cases of personal neglect that were diagnosed using the %left index were also diagnosed using the %bias index. 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).
for 40 patients tested twice was excellent (r = 0.95).

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. More.

Should not be used with:

• Patients who do not have unilateral voluntary movement and control of the shoulder, elbow, and fingers.
• Need to rule out the presence of apraxia, given that this may impact the validityThe degree to which an assessment measures what it is supposed to measure.
  of testing results.

In what languages is the measure available?

Not applicable.

Summary

What does the tool measure?	Unilateral Spatial Neglect (USN) in personal space
What types of clients can the tool be used for?	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. More
Is this a screeningTesting for disease in people without symptoms. or assessment tool?	ScreeningTesting for disease in people without symptoms. .
Time to administer	Less than 5 minutes.
Versions	Reformulated Comb and Razor Test
Other Languages	Not applicable.
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 Comb and Razor Test. Test-retest: Two studies have 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 Comb and Razor Test and both studies reported excellent test-retest. Inter-rater: No studies have 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 Comb and Razor Test.
ValidityThe degree to which an assessment measures what it is supposed to measure.	Construct: Known groups: The Comb and Razor Test is able to discriminate between different groups of subjects (i.e. patients with right brain 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, with or without extra personal neglect, patients with left brain 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, as well as healthy individuals).
Does the tool detect change in patients?	Not applicable.
Acceptability	The Comb and Razor Test should be used as a screeningTesting for disease in people without symptoms. tool rather than for clinical diagnosis of USN. Apraxia must be ruled out as this may affect the validityThe degree to which an assessment measures what it is supposed to measure. of test results. This test cannot be completed by proxy. Patients who do not have unilateral voluntary movement and control of the shoulder, elbow, and fingers cannot complete the test.
Feasibility	The Comb and Razor Test requires no specialized training to administer and only simple equipment is required (a razor with shield, a compact case, a comb, and a stopwatch). The test is fairly simple to score and interpret, calculated using a mathematical equation. Cutoff scores for the presence of left or right neglect are provided.
How to obtain the tool?	Not applicable. To conduct the Comb and Razor Test, the clinician asks the patient to demonstrate the use of two common objects for 30 seconds each: 1. comb and 2. razor or powder compact case. Each object is placed at the patient’s midline. A dialogue has been created for administering the Comb and Razor Test. See Features of the measures in the in-depth review section.

Psychometric Properties

Overview

For the purposes of this review, we conducted a literature search to identify all relevant publications on the psychometric properties of the Comb and Razor Test as a measure of USN. Although easy to use, this tool has only minimal evidence of 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 .
and validityThe degree to which an assessment measures what it is supposed to measure.
(Menon & Korner-Bitensky, 2004). Further studies examining the psychometric properties of the test have had small sample sizes. More testing is required prior to clinical use.

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. 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 Comb and Razor Test.

Test-retest:
Beschin and Robertson (1997) 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 Comb and Razor Test. Forty-three 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. More were assessed twice. In this study, 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 Comb and Razor Test was excellent (r = 0.94).

McIntosh et al. (2000) 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 a reformulated version of the Comb and Razor Test and compared it to the original version by Beschin and Robertson (1997). Forty patients who were administered the test were reassessed at a later time. The original Comb and Razor Test had excellent 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).
(r = 0.94).

Inter-rater:
No studies have 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 Comb and Razor Test.

Validity

Construct:
Known groups:
Beschin and Robertson (1997) examined the psychometric properties of the Comb and Razor Test in 17 patients with right brain 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 extra personal neglect, 14 without unilateral extra personal neglect, 13 patients with left brain 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 17 age-matched controls. An analysis of variance (ANOVA) by group shows that the four samples of subjects significantly differed in their performance [F (3, 57) = 18.0; p < 0.0001]. A series of Fisher’s post hoc exact tests showed significant differences between all the pairs of groups, with the exception of the left brain damage group who did not differ significantly from the control group. Therefore, this tool is able to discriminate between different groups of subjects (i.e. patients with right brain 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, with or without extra personal neglect, patients with left brain 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, as well as healthy individuals).

McIntosh et al. (2000) examined the validityThe degree to which an assessment measures what it is supposed to measure.
of a reformulated version of the Comb and Razor Test in 88 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. More: 17 with right brain damage and extra personal neglect, 14 with right brain damage and no extra personal neglect, 13 with left brain damage, and 44 age-matched controls. Mean scores for each group were as follows: patients with right brain damage and extra personal neglect scored 0.25, patients with right brain damage and no extra personal neglect scored 0.37, patients with left brain damage scored 0.46, and controls scored 0.43. An ANOVA by group performed upon the % left scores was highly significant [F (3, 84) = 27.54; p < 0.0001] and Fisher’s post-hoc exact tests found significant differences between all pairs of groups. Therefore, this tool is able to discriminate between different groups of subjects (i.e. patients with right brain 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, with or without extra personal neglect, patients with left brain 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, as well as healthy individuals).

Criterion;
No studies have examined the criterion validityExamines the extent to which a measure provides results that are consistent with a gold standard . It is typically divided into concurrent validity and predictive validity .
of the Comb and Razor Test.

Responsiveness

No studies have examined the responsivenessThe ability of an instrument to detect clinically important change over time.
of the Comb and Razor Test.

References

• Beschin, N., Robertson, I. H. (1997). Personal versusextrapersonal neglect: a group study of their dissociation using areliable clinical test. Cortex. 33, 379-384.
• McIntosh, R. D., Brodie, E. E., Beschin, N., et al. (2000). Improving the clinical diagnosis of personal neglect: a reformulated comb and razor test. Cortex, 36,
  289-292.
• Menon, A., Korner-Bitensky, N. (2004). Evaluating unilateral spatial neglect post stroke: Working your way through the maze of assessment choices. Topics in Stroke Rehabilitation, 11(3), 41-66.
• Zoccolotti, P., Judica, A. (1991). Functional evaluation of hemineglect by means of a semistructured scale: Personal extrapersonal differentiation. Neuropsychological Rehabilitation, 1, 33-34.
• Zoccolotti, P., Antonucci, G., Judica, A. (1992). Psychometric characteristics of two semi-structured scales for the functional evaluation of hemi-inattention in extrapersonal and personal Space. Neuropsychological Rehabil, 2, 179-191.

See the measure

To complete the comb and razor test, one simply requires a comb, razor, and powder compact case.