Clock drawing task, mini-mental state examination and cognitive-functional independence measure: Relation to functional outcome of stroke patients

The use of reliable and valid brief cognitive screening instrument for selecting the appropriate candidates for stroke rehabilitation is crucial. Clinicians often face the question which test should be preferred, that will best correlate with functional outcome. The objective of this study was to compare the clock drawing task with other cognitive tests used for the evaluation of discharge functional outcome in elderly stroke patients. We conducted a retrospective chart study including 151 consecutive patients, admitted for inpatient comprehensive rehabilitation following acute stroke. The clock drawing task (CDT), mini-mental state examination (MMSE) and the cognitive-functional independence measure (cognFIM) were used to assess the cognitive status. Functional status outcome was evaluated by the functional independence measure (FIM), using absolute and relative parameters of efficacy and efficiency. Correlation coefficients (Pearson correlation) between the three cognitive tests resulted in r-values ranging from 0.51 to 0.59 (P<0.001). All three tests correlated significantly with motor outcomes. MMSE did not confer additive value to CDT. It is concluded that CDT is similar to mini-mental and both are somewhat better than cognFIM with respect to the evaluation of functional status outcome following stroke. The correlations between the tests as well as the simplicity of administration favor the use of either CDT or MMSE in the initial assessment of elderly stroke patients.