Concepts of capacity and performance in assessment of functioning amongst stroke survivors: A comparison of the Functional Independence Measure and the International Classification of Functioning, Disability and Health

To investigate the use of concepts of capacity and performance when assessing functioning of stroke survivors, measured with the Functional Independence Measure (FIM) and the International Classification of Functioning, Disability and Health (ICF). During an inpatient interdisciplinary rehabilitation programme for 62 subacute stroke survivors, limitations in speaking, walking, toileting and eating were assessed at admission and discharge with both the FIM and a scale based on the ICF Brief Core Set for stroke. Correlation between the results obtained with these 2 scales was assessed using Spearman's correlation coefficient. The level of restriction of functioning, defined as capacity or performance in terms of the ICF, correlated well with the results obtained with the FIM (0.47-0.87) . The only statistically significant difference was found in assessing limitations in eating, where assessment with the FIM had a higher correlation with the concept of capacity than performance (0.75 vs 0.55). The observed correlations were not associated with stroke severity. Even though the FIM and an ICF-based scale may describe limitation of functioning of stroke survivors similarly, ICF is probably more comprehensive in describing both capacity and performance.