I. Evaluation of the functional capacity of stroke patients through an activity index.

An evaluation instrument, the Activity Index (AI), has been constructed for measuring the functional capacity of stroke patients from the acute phase of the disease onwards. The Index consists of 16 variables divided into three main parts: mental capacity, motor activity, and ADL function. The maximum score is 92. In a group of 112 stroke patients the Cronbach alpha reliability coefficient for the total AI was 0.94, indicating a high degree of homogeneity of the test. The Spearman rank correlation coefficient between the AI and the Rankin disability scale was -0.94. The results of a bivariate linear regression analysis between the values of the Activity Index on admission (about 48 hours after the stroke) and the scoring on later test occasions, grouped as dead, low score, medium score, high score, respectively, indicated the instrument's high predictive validity. The AI can be used by different categories of trained staff in clinical practice or clinical research.