- Email: [email protected]
Clock drawing in the screening assessment of cognitive impairment in an ambulatory care setting: A preliminary report
Clock Drawing in the Screening Assessment of Cognitive Impairment in an Ambulatory Care Setting: A Preliminary Report James A. Huntzinger, M.D., Richard B. Rosse, M.D., Barbara L. Schwartz, Ph.D., Louis A. Ross, M.D., and Stephen I. Deutsch, M.D., Ph.D. Abstract: In an exploratory study to assess the utility of clock drawing as a screeningtest for cognitive impairment in medicall surgical outpatients, clock drawing and the 6-item OrientationMemory-Concentration Test (OMCTJ were administered to over 400 randomly selected ambulatory patients over the age of 55 in a busy inner-cify hospital. The clock drawing test was completed by 431 patients, and 471 completed the OMCT. Clock drawing errors suggestive ofmoderate-to-severe cognitive impairment were found in 42.7% of patients; OMCT errors suggestive of moderate-to-severe cognitive impairment were found in 35.4% of the population tested. The clock drawing test migkt represent a quick-screen for cognitive impairment in an older general medical/surgical outpatient population, and migkt kelp identify patients not otherwise recognized as QOtentially unable to fully understand treatment recommendations.
Introduction Epidemiological surveys suggest that cognitive impairment is unrecognized in a significant number of elderly persons over the age of 65 years [l-4]. It is of considerable importance to current systems of health care that such impairment be recognized so that the special needs of these patients can be met. There are currently a number of screening tests that are used to assess cognitive impairment, From the Psychiatry Service, VA Medical Center, Washington D.C. and Georgetown University School of Medicine Washington D.C. Address reprint requests to: Stephen I. Deutsch, M.D., Ph.D., Chief, Psychiatry Service (116A), Department of Veterans Affairs Medical Center, 50 Irving St., NW, Washington, DC 20422.
142 ISSN 0163-8343/921$5.00
such as the Mini-Mental State Examination (MMSE), Cognitive Capacity Screening Examination (CCSE), Hand-Held Tachistoscope [5], and the Neurobehavioral Cognitive Status Examination [6]. The advantage of some of these cognitive screening batteries such as the MMSE is that multiple cognitive abilities can be briefly assessed (e.g, orientation, attention, memory, reading, writing, receptive and expressive speech, calculation, and construction). However, to administer most of these tests, the health care worker needs a copy of the test to ensure proper questioning, as well as special equipment, such as a hand-held tachistoscope [5]. By contrast, the Clock Drawing Test (a measure of visuospatial skills [7-91) can be administered rapidly with great ease in a busy ambulatory health care environment (e.g., approximately 1 minute for the Clock Drawing Test, vs about 5 minutes for the MMSE or CCSE 151). Moreover, the results of the Clock Drawing Test are often surprising and dramatic and can serve to usefully communicate to the health care worker the presence of some cognitive impairment in a seemingly intact individual [9]. We conducted a pilot study to assess the utility of clock drawing [7-91 in detecting previously unrecognized cognitive impairment in outpatients aged 55 years and older in a general medical ambulatory care setting, comprised of specialty and subspecialty medical and surgical clinics in an inner-city Department of Veterans Affairs Medical Center. In the present study, we also used the General HospiM Psychiatry 14, 142-144, 1992 0 1992 Elsevier Science Publishing Co., Inc. 655 Avenue of the Americas, New York, NY 10010
Clock Drawing in Cognitive
6-item Orientation-Memory-Concentration Test (OMCT) [lo] which is a shortened version of the Information-Memory-Concentration Mental Status Test devised by Blessed et al. [ll]. In this sample, we obtained information concerning the number of patients with moderate-to-severe cognitive impairment, as measured by the Clock Drawing Test and OMCT, who were unaccompanied to their outpatient appointment.
Method In a 4-month period, 500 veterans, aged 55-95 years (mean = 67.1, SD = 6.93), were approached randomly by a senior attending psychiatrist and asked to complete the OMCT and the Clock Drawing Test. These patients were solicited for entry into the study while they were waiting to be seen for their scheduled appointments in a variety of medical and surgical clinics, which did not include clinics in neurology or psychiatry. After the psychiatrist inquired about demographic information, he administered to the patients the OMCT followed by the Clock Drawing Test. The OMCT was administered and scored according to the instructions by Katzman et al. [lo], with scores ranging from 0 to 28 errors. The following ranges were used as cutoff values reflecting degree of cognitive impairment: O-8 errors (normal/mild) [lo], 9-16 errors (moderate), and 17-28 errors (severe). In the Clock Drawing Test, patients were given a blank sheet of paper and were asked to “draw a clock with all the numbers on it and set the hands at 2:45.” Two raters came to a consensus score for the Clock Drawing Test using the criteria proposed by Sunderland et al. [7]. These raters were unaware of the patient’s performance on the OMCT. The scores on the Clock Drawing Test range from 10 (“perfect”) to 0 (lowest). The range of scores reflecting degree of cognitive impairment in this test were S10 (normal/mild), 5-7 (moderate), and less than 5 (severe).
Results There were 478 patients (95.6%) who agreed to participate in this study. Of those who participated, 471 completed the OMCT. The percentage of patients who scored within each level of cognitive impairment on the OMCT was 64.53% in the normal/mild range, 29.29% in the moderate range, and 6.14% in the severe range. The number of patients who completed the Clock Drawing Test was 431.
Assessment
The percentage of patients who scored within each level of impairment on this test was 57.31% in the normal/mild range, 10.91% in the moderate range, and 31.79% in the severe range. A comparison of the relative sensitivity of the two screening tests showed that the OMCT did not identify 7% of the patients who had moderate-tosevere impairment on the Clock Drawing Test, namely, a moderate-to-severe impairment in a visuospatial skill. Moreover, there tended to be only a moderate, albeit significant, correlation between performance on these two tests (Pearson’s r = -0.30, p < 0.001). These results suggest that although there was some degree of overlap in performance between the two tests, administration of both the OMCT and the Clock Drawing Test gave a more complete picture of cognitive impairment in our sample. In a sample of 375 patients who performed the Clock Drawing Test, 324 patients came to their clinic appointment unaccompanied, without spouse or caregiver. Interestingly, of these 324 patients, 31% performed in the severely impaired range of the Clock Drawing Test.
Discussion The primary focus of this study was to ascertain the possible utility of clock drawing as an easily administered screening evaluation for cognitive impairment. Errors on the clock drawing test suggestive of moderate-to-severe cognitive impairment were found in 42.7% of the subjects tested. Errors on the OMCT suggestive of such impairment was found in 35.43% of this population. More thorough and formal neuropsychological and cognitive assessment would be needed to validate the levels of impairment suggested by the cognitive screening tests used in this study. Nevertheless, based on the results of this study, the Clock Drawing Test might represent a useful screening test for cognitive impairment that would be readily accepted and utilized by health care workers in ambulatory medical care settings. However, because there does not appear to be a higher correlation between clock drawing and OMCT performance, the clinician should not assume that all forms of cognitive impairment will be detected by a simple Clock Drawing Test. Unfortunately, more extensive neuropsychological testing in this population is expensive and time-consuming for hospital staff and taxing for patients [12], and in this era of cost containment in health care, it would seem impor143
J. A. Huntzinger et al.
tant to be able to establish ways to economically and reliably identify patients with cognitive impairment who are at risk of inefficient utilization of health care system recommendations. Though we did not formally study our patients’ abilities to understand treatment recommendations, we wonder about the ability of patients who scored in the moderate-to-severe range on the Clock Drawing Test to comprehend and comply with their physicians’ recommendations. It was of further concern that 31% of the patients who performed in the severe range on clock drawing came to the clinic unaccompanied by someone to whom health care instructions could have been provided to augment the chances of more successful treatment compliance . It would be vitally important that the presence of crippling conditions such as arthritis or visual impairment be understood as potential explanations of poor clock drawing performance. Indeed, infirmity due to a wide variety of physical illnesses could explain clock drawing impairments. Future studies will need to explore the influence of such confounding variables on clock drawing performance. To tease out the effect of nonbrain impairments on clock drawing, patients with Clock Drawing Test results possibly tainted by nonbrain impairments could receive more thorough cognitive testing. Impaired clock drawing is not necessarily specific to central nervous system (CNS) disturbances, nor is it specific to particular CNS etiologies of cognitive impairment; any acute or chronic brain condition can cause impaired clock drawing. Future research should also compare the Clock Drawing Test to such popular screening tests as the MMSE in terms of patient and health care worker acceptance, convenience, rates of falsepositives and negatives, and utility in anticipating patient compliance problems related to cognitive impairment. In this study there was no follow-up neuropsychological and other diagnostic testing to help us better assess rates of false-positives and negatives with the Clock Drawing Test; such future work would be important. Nevertheless, our in-
144
creasingly busy general medical/surgical outpatient areas need to have a quick, easily administered cognitive screening test to detect potential cognitive impairment and treatment compliance problems that might stem from such impairment, especially for geriatric patients. Clock drawing might represent such a test.
References 1. Evans DA, Funkenstein HH, Albert MS, et al: Prevalence of Alzheimer’s disease in a community population of older persons. AMA 262:2551-2556, 1989 2. Schoenberg BS, Kokmen E, Okazaki H: Alzheimer’s disease and other dementing illnesses in a defined United States population: incidence rates and clinical features. Ann Neurol22:724-729, 1987 3. Kay DWK, Beamish P, Roth M: Old age mental disorders in Newcastle upon Tyne. Br J Psychiatxy 110: 146-158, 1964 4. Mortimer JA, Schuman LM, French LR: Epidemiology of dementing illness. In Mortimer JA, Schuman LM (eds), The Epidemiology of Dementia. New York, Oxford University Press, 1981 5. Strain JJ, Fulop G, Lebovits A, et al. Screening devices for diminished cognitive capacity. Gen Hosp Psychiatry 10:16-23, 1988 6. Kieman RJ, Mueller J, Langston JW, Van Dyke C: The Neurobehavioral Cognitive Status Examination: a brief but differentiated approach to cognitive assessment. Ann Intern Med 107:481-485, 1987 7. Sunderland T, Hill JL, Mellow AM, et al: Clock drawing in Alzheimer’s disease. J Am Geriatr Sot 37:725729, 1989 8. Wolf-Klein GP, Silverstone FA, Levy Al’, et al.: Screening for Alzheimer’s disease by clock drawing. J Am Geriatr Sot 37~730-734, 1989 9. Wise M: Delirium. In Hales RE, Yudofsky SC (eds), Textbook of Neuropsychiatry. Washington DC, American Psychiatric Press, 1987, pp 89-105 10. Katzman R, Brown T, Fuld P, et al: Validation of a short orientation-memory-concentration test of cognitive impairment. Am J Psychiatry 140:734-739, 1983 11. Blessed G., Tomlinson BE, Roth M: The association between quantitative measures of dementia and of senile change in the cerebral grey matter of elderly subjects. Br J Psychiatry 114:797-811, 1968 12. Fulop G, Strain JJ: Diagnosis and treatment of psychiatric disorders in medically ill inpatients. Hosp Community Psychiatry 42:389-394, 1991
Introduction Epidemiological surveys suggest that cognitive impairment is unrecognized in a significant number of elderly persons over the age of 65 years [l-4]. It is of considerable importance to current systems of health care that such impairment be recognized so that the special needs of these patients can be met. There are currently a number of screening tests that are used to assess cognitive impairment, From the Psychiatry Service, VA Medical Center, Washington D.C. and Georgetown University School of Medicine Washington D.C. Address reprint requests to: Stephen I. Deutsch, M.D., Ph.D., Chief, Psychiatry Service (116A), Department of Veterans Affairs Medical Center, 50 Irving St., NW, Washington, DC 20422.
142 ISSN 0163-8343/921$5.00
such as the Mini-Mental State Examination (MMSE), Cognitive Capacity Screening Examination (CCSE), Hand-Held Tachistoscope [5], and the Neurobehavioral Cognitive Status Examination [6]. The advantage of some of these cognitive screening batteries such as the MMSE is that multiple cognitive abilities can be briefly assessed (e.g, orientation, attention, memory, reading, writing, receptive and expressive speech, calculation, and construction). However, to administer most of these tests, the health care worker needs a copy of the test to ensure proper questioning, as well as special equipment, such as a hand-held tachistoscope [5]. By contrast, the Clock Drawing Test (a measure of visuospatial skills [7-91) can be administered rapidly with great ease in a busy ambulatory health care environment (e.g., approximately 1 minute for the Clock Drawing Test, vs about 5 minutes for the MMSE or CCSE 151). Moreover, the results of the Clock Drawing Test are often surprising and dramatic and can serve to usefully communicate to the health care worker the presence of some cognitive impairment in a seemingly intact individual [9]. We conducted a pilot study to assess the utility of clock drawing [7-91 in detecting previously unrecognized cognitive impairment in outpatients aged 55 years and older in a general medical ambulatory care setting, comprised of specialty and subspecialty medical and surgical clinics in an inner-city Department of Veterans Affairs Medical Center. In the present study, we also used the General HospiM Psychiatry 14, 142-144, 1992 0 1992 Elsevier Science Publishing Co., Inc. 655 Avenue of the Americas, New York, NY 10010
Clock Drawing in Cognitive
6-item Orientation-Memory-Concentration Test (OMCT) [lo] which is a shortened version of the Information-Memory-Concentration Mental Status Test devised by Blessed et al. [ll]. In this sample, we obtained information concerning the number of patients with moderate-to-severe cognitive impairment, as measured by the Clock Drawing Test and OMCT, who were unaccompanied to their outpatient appointment.
Method In a 4-month period, 500 veterans, aged 55-95 years (mean = 67.1, SD = 6.93), were approached randomly by a senior attending psychiatrist and asked to complete the OMCT and the Clock Drawing Test. These patients were solicited for entry into the study while they were waiting to be seen for their scheduled appointments in a variety of medical and surgical clinics, which did not include clinics in neurology or psychiatry. After the psychiatrist inquired about demographic information, he administered to the patients the OMCT followed by the Clock Drawing Test. The OMCT was administered and scored according to the instructions by Katzman et al. [lo], with scores ranging from 0 to 28 errors. The following ranges were used as cutoff values reflecting degree of cognitive impairment: O-8 errors (normal/mild) [lo], 9-16 errors (moderate), and 17-28 errors (severe). In the Clock Drawing Test, patients were given a blank sheet of paper and were asked to “draw a clock with all the numbers on it and set the hands at 2:45.” Two raters came to a consensus score for the Clock Drawing Test using the criteria proposed by Sunderland et al. [7]. These raters were unaware of the patient’s performance on the OMCT. The scores on the Clock Drawing Test range from 10 (“perfect”) to 0 (lowest). The range of scores reflecting degree of cognitive impairment in this test were S10 (normal/mild), 5-7 (moderate), and less than 5 (severe).
Results There were 478 patients (95.6%) who agreed to participate in this study. Of those who participated, 471 completed the OMCT. The percentage of patients who scored within each level of cognitive impairment on the OMCT was 64.53% in the normal/mild range, 29.29% in the moderate range, and 6.14% in the severe range. The number of patients who completed the Clock Drawing Test was 431.
Assessment
The percentage of patients who scored within each level of impairment on this test was 57.31% in the normal/mild range, 10.91% in the moderate range, and 31.79% in the severe range. A comparison of the relative sensitivity of the two screening tests showed that the OMCT did not identify 7% of the patients who had moderate-tosevere impairment on the Clock Drawing Test, namely, a moderate-to-severe impairment in a visuospatial skill. Moreover, there tended to be only a moderate, albeit significant, correlation between performance on these two tests (Pearson’s r = -0.30, p < 0.001). These results suggest that although there was some degree of overlap in performance between the two tests, administration of both the OMCT and the Clock Drawing Test gave a more complete picture of cognitive impairment in our sample. In a sample of 375 patients who performed the Clock Drawing Test, 324 patients came to their clinic appointment unaccompanied, without spouse or caregiver. Interestingly, of these 324 patients, 31% performed in the severely impaired range of the Clock Drawing Test.
Discussion The primary focus of this study was to ascertain the possible utility of clock drawing as an easily administered screening evaluation for cognitive impairment. Errors on the clock drawing test suggestive of moderate-to-severe cognitive impairment were found in 42.7% of the subjects tested. Errors on the OMCT suggestive of such impairment was found in 35.43% of this population. More thorough and formal neuropsychological and cognitive assessment would be needed to validate the levels of impairment suggested by the cognitive screening tests used in this study. Nevertheless, based on the results of this study, the Clock Drawing Test might represent a useful screening test for cognitive impairment that would be readily accepted and utilized by health care workers in ambulatory medical care settings. However, because there does not appear to be a higher correlation between clock drawing and OMCT performance, the clinician should not assume that all forms of cognitive impairment will be detected by a simple Clock Drawing Test. Unfortunately, more extensive neuropsychological testing in this population is expensive and time-consuming for hospital staff and taxing for patients [12], and in this era of cost containment in health care, it would seem impor143
J. A. Huntzinger et al.
tant to be able to establish ways to economically and reliably identify patients with cognitive impairment who are at risk of inefficient utilization of health care system recommendations. Though we did not formally study our patients’ abilities to understand treatment recommendations, we wonder about the ability of patients who scored in the moderate-to-severe range on the Clock Drawing Test to comprehend and comply with their physicians’ recommendations. It was of further concern that 31% of the patients who performed in the severe range on clock drawing came to the clinic unaccompanied by someone to whom health care instructions could have been provided to augment the chances of more successful treatment compliance . It would be vitally important that the presence of crippling conditions such as arthritis or visual impairment be understood as potential explanations of poor clock drawing performance. Indeed, infirmity due to a wide variety of physical illnesses could explain clock drawing impairments. Future studies will need to explore the influence of such confounding variables on clock drawing performance. To tease out the effect of nonbrain impairments on clock drawing, patients with Clock Drawing Test results possibly tainted by nonbrain impairments could receive more thorough cognitive testing. Impaired clock drawing is not necessarily specific to central nervous system (CNS) disturbances, nor is it specific to particular CNS etiologies of cognitive impairment; any acute or chronic brain condition can cause impaired clock drawing. Future research should also compare the Clock Drawing Test to such popular screening tests as the MMSE in terms of patient and health care worker acceptance, convenience, rates of falsepositives and negatives, and utility in anticipating patient compliance problems related to cognitive impairment. In this study there was no follow-up neuropsychological and other diagnostic testing to help us better assess rates of false-positives and negatives with the Clock Drawing Test; such future work would be important. Nevertheless, our in-
144
creasingly busy general medical/surgical outpatient areas need to have a quick, easily administered cognitive screening test to detect potential cognitive impairment and treatment compliance problems that might stem from such impairment, especially for geriatric patients. Clock drawing might represent such a test.
References 1. Evans DA, Funkenstein HH, Albert MS, et al: Prevalence of Alzheimer’s disease in a community population of older persons. AMA 262:2551-2556, 1989 2. Schoenberg BS, Kokmen E, Okazaki H: Alzheimer’s disease and other dementing illnesses in a defined United States population: incidence rates and clinical features. Ann Neurol22:724-729, 1987 3. Kay DWK, Beamish P, Roth M: Old age mental disorders in Newcastle upon Tyne. Br J Psychiatxy 110: 146-158, 1964 4. Mortimer JA, Schuman LM, French LR: Epidemiology of dementing illness. In Mortimer JA, Schuman LM (eds), The Epidemiology of Dementia. New York, Oxford University Press, 1981 5. Strain JJ, Fulop G, Lebovits A, et al. Screening devices for diminished cognitive capacity. Gen Hosp Psychiatry 10:16-23, 1988 6. Kieman RJ, Mueller J, Langston JW, Van Dyke C: The Neurobehavioral Cognitive Status Examination: a brief but differentiated approach to cognitive assessment. Ann Intern Med 107:481-485, 1987 7. Sunderland T, Hill JL, Mellow AM, et al: Clock drawing in Alzheimer’s disease. J Am Geriatr Sot 37:725729, 1989 8. Wolf-Klein GP, Silverstone FA, Levy Al’, et al.: Screening for Alzheimer’s disease by clock drawing. J Am Geriatr Sot 37~730-734, 1989 9. Wise M: Delirium. In Hales RE, Yudofsky SC (eds), Textbook of Neuropsychiatry. Washington DC, American Psychiatric Press, 1987, pp 89-105 10. Katzman R, Brown T, Fuld P, et al: Validation of a short orientation-memory-concentration test of cognitive impairment. Am J Psychiatry 140:734-739, 1983 11. Blessed G., Tomlinson BE, Roth M: The association between quantitative measures of dementia and of senile change in the cerebral grey matter of elderly subjects. Br J Psychiatry 114:797-811, 1968 12. Fulop G, Strain JJ: Diagnosis and treatment of psychiatric disorders in medically ill inpatients. Hosp Community Psychiatry 42:389-394, 1991