EVALUATION OF A MENTAL TEST SCORE FOR ASSESSMENT OF MENTAL IMPAIRMENT IN THE ELDERLY

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1 Age and Ageing (1972) 1, 233 EVALUATION OF A MENTAL TEST SCORE FOR ASSESSMENT OF MENTAL IMPAIRMENT IN THE ELDERLY H. M. HODKINSON Northteick Park Hospital, Harrow, Middlesex Summary A mental test tcore consisting of 26 questions testing memory and orientation was used in a large inpatient study of mental impairment of the elderly. Analysis shows that the questions varied considerably in their discriminatory value. Deletion of the less effective questions results in an abbreviated test of ten questions with similar discriminatory powers to the full test. Shorter tests of this kind are recommended for further practical evaluation in geriatric departments. INTRODUCTION I A mental test' score (Appendix I) closely based on that of Blessed, Tomlinson & Roth (1) was used to assess mental impairment in an extensive multi-centre study of mental disorders in the elderly hospital inpatient (Hodkinson, 1972) conducted under the auspices of the Royal College of Physicians, London. A preliminary survey had shown that our version of the test gave a good practical separation between patients who were mentally normal and those with confusional states or dementia and that a score of from 25 to the maximum of 34 could be accepted as the normal range (Lloyd, 197). The test result was of no value in distinguishing mental impairment due to a confusional state from that due to dementia, the pattern of score loss being no different in the two groups, but serial use of the test helped in the recognition of confusional states by quantitating changes in mental performance (Hodkinson, 1972). MATERIAL AND METHODS Over 7 patients aged 65 and above received the test in the Royal College study. The test was administered serially but in the present analyses only the initial test, carried out within the first four days in hospital, has been considered. Drowsy or dysphasic patients were not studied and where deafness interfered with administration of the test, a large print visual presentation of the test was utilized. The analyses are of the combined dementia (scores -24) and mentally-normal (scores 25 34) groups of patients in the Royal College study. Downloaded from at Pennsylvania State University on February 1, 216 RESULTS Table I shows the percentage of correct answers scored for each question across the range of total scores. Patients have been grouped in score categories offivepoint range for this purpose but those scoring 34 were omitted as their score of per cent marks for all questions gives no information as to the relative performance of questions, this being the object of the analysis. The analysis shows that the questions vary considerably in their overall difficulty; question 1 is clearly the easiest and questions 7 and 21 the hardest For

2 234 H. M. Hodkinson TabU I Total score Question Name Age Time, to nearest hour Time of day Recall of address Day of week Date Month Year Type of place Name of hospital Name of ward Name of town Recognition of two persons Date of birth Place of birth School attended Former occupation Name of next of kin Date of First World War Date of Second World War Name of present Monarch Name of present Prime Minister Months of year backwards Counting 1-2 Counting 2-1 Whole questionaire % SCORE FH3 QUESTIONS % Downloaded from at Pennsylvania State University on February 1, MTS KH4-192O-24S-W3O-33 Fig. 1. Percentage score for three questions. MTS» Mental test score.

3 Evaluation of a Mental Test Score 235 many questions the degree of difficulty varies through the score range relative to other questions and three broad patterns of behaviour can be recognized. Fig. 1, showing the scoring patterns of questions 19, 14 and 21 graphically, exemplifies these three groups. Question 19 shows a pattern of score loss confined to the low scoring groups i.e. it has discriminant value only at low total scores. Question 14 shows a regular pattern of loss across the whole score range i.e. it discriminates throughout the range. Question 21 has negligible scores until the higher total scores are reached i.e. it has discriminant value only at the top of the score range. Fig. 2 contrasts the low-score-discriminator and highscore-discriminator groups of questions, whilst Fig. 3 illustrates the performance of questions showing discriminant value throughout the total score range. MTS Fig. 2. Comparison of low-score-discriminator and high-score-discriminator group* of questions. 9- to- 2,5.4,1.11, 12.13,14, t Downloaded from at Pennsylvania State University on February 1, 216 re MTS JO-33 Fig. 3. Performance of questions showing discriminant value throughout total score range.

4 236 H. M. Hodkmson The questions include several closely linked groups, e.g. questions 3 and 4 (time), 6-9 (date), 1-13 (place) and 19 (personal details). Many related questions show very closely similar patterns of loss and Fig. 4 illustrates this for two groups. Questions 3 and 4 and 1-13 behave similarly. loo-i MTS Fig. 4. Similarity of pattern* for two groups of related questions. DISCUSSION If a test can be shortened without appreciable loss of its discriminatory powers, this is obviously worth while to those using it Added to this is the question of acceptability of the test to the patients receiving it Although the present test proved a practicable one which was not unduly time-consuming, its length did appear to tax the concentration and patience of some demented old people. Experience in my own department using the present test and a somewhat similar one of about half its length (Denham & Jefferys, 1972) has shown that the shorter test achieves far more consistent cooperation from our patients. It would appear from the results of the analyses of the mental test score that the exclusion of all but one of each group or related questions which gave similar patterns of score loss would have little effect on the overall value of the test. Nine questions could be removed on this basis. Additional candidates for elimination are those in the groups which discriminate only at high or low total score. Question 1 which only drops marks among the patients scoring less than five could clearly be omitted with impunity. Question 25 could similarly go as being too easy whilst question 24 (months of the year backwards) might be omitted as it is perhaps too hard, it certainly appeared to be the question most likely to irritate or upset patients. Questions 21 and 23 might be deleted on the grounds of their pairings with rather similar questions (2 and 22 respectively) which are effective throughout the score range. This would give a test of only ten questions instead of 26. It might be advisable to abandon the score weightings for questions 5, 14 and 26 and in consequence of this it would be an advantage to simplify the name and address given for Downloaded from at Pennsylvania State University on February 1, 216

5 Evaluation of a Mental Test Score 237 recall. Appendix II illustrates a possible shortened form of the test based on these suggestions. A comparison of this abbreviated mental test score with the full test was carried out by rescoring from the recorded results of 21 tests from the Royal College of Physicians study (six for each score category, -34, of the full test). The correlation found is shown in Fig. 5 and is acceptably close to a linear relationship. Scatter of results is such that only two of the 21 results lie more than ± 1 abbreviated-test-point from the medians) for that full mental test score category. These findings indicate that the abbreviated test gives comparable results to the full mental test score and could replace it where the test is being used to recognize mental impairment. Scores below seven closely correspond to those Ur mil B 2 3 X FUU.tWTAl.irsT SCOW Fig. 5. Comparison of scores on abbreviated mental tett and full mental test. below the lower limit of 25 for the full test. The abbreviated test, with its coarser gradations, might prove less satisfactory for showing serial changes to assist in the recognition of confusional states. Further exploration of its use would be needed to elucidate this point. As the abbreviated test appears to have advantages over the full test for routine geriatric use further studies would seem to be worth while. ACKNOWLEDGEMENTS The author wishes to thank the Royal College of Physicians for his appointment as Hon. Anniversary Research Fellow, enabling him to carry out this work as a part of the Study of Mental Impairment in the Elderly and wishes again to record his thanks to the participating physicians and their staff who were responsible for the administration of the mental test score. REFERENCES BLESSED, G., TOMLINSON, B. E. & ROTH, M. (1). The association between qualitative measures of dementia and senile change in the cerebral grey matter of elderly subjects. Br. J. Psycktat. 114, 797. DENHAM, M. J. & JEFFEHYS, P. M. (1972). Routine mental assessment in elderly patients. Modern Geriatrics, 2, 27S. HODKINSON, H. M. (1972). Mental impairment in the elderly. A study in 21 geriatric departments, sponsored by the Royal College of Physicians of London. Awaiting publication. LLOYD, C. M. (197). Royal College of Physicians' Study of mental impairment in the elderly. Report of findings of pilot study. London: Royal College of Physicians. 22 Downloaded from at Pennsylvania State University on February 1, 216

6 23 H,M- Hodkxnson APPENDIX I MENTAL TEST SCORE Name Age Time (to nearest hour) Time of day Name and address for five minutes recall, this should be repeated by the patient to ensure it has been heard correctly. Mr John Brown 42 West Street Gateshead Day of week Date (correct day of month) Month Year Place: Type of place (i.e. Hospital) Name of hospital Name of ward Name of town Recognition of two persons (doctor, nurse, etc.) Date of birth (day and month sufficient) Place of birth (town) School attended Former occupation Name of wife, sib or next of kin Date of First World War (year sufficient) Date of Second World War (date sufficient) Nams of present Monarch Name of present Prime Minister Months of year backwards Count 1-2 Count 2-1 Total APPENDIX II ABBREVIATED MENTAL TEST SCORE (Each question scores one mark) Score /1 /1 /1 /1 /1/2 /1/2 /1 /1 /1 /1 /1 /1 /1 /1 /1/2 /1 /1 /1 /1 /1 /1 /1/2 /1/2 /1/2 (34) 1. Age 2. Time (to nearest hour) 3. Address for recall at end of test this should be repeated by the patient to ensure it has been heard correctly: 42 West Street 4. Year 5. Name of hospital 6. Recognition of two persons (doctor, nurse, etc.) 7. Date of birth. Year of First World War 9. Name of present Monarch 1. Count backwards 2-1 Downloaded from at Pennsylvania State University on February 1, 216