Development of a measure of functioning for stroke recovery: the functional recovery measure.

Abstract

To develop a parsimonious measure of functioning for persons after stroke. A sub-set of 206 community-dwelling subjects with a first stroke from a larger cohort was interviewed within 9 months using 39 items from five indices assessing functioning. Information was collected on influencing variables: age, stroke type and severity, and previous health. Two statistical methods, factor analysis and Rasch analysis, confirmed the item structure, hierarchy and dimensionality of the measure. Statistics confirmed fit to the model; internal consistency was also assessed. Items were deleted iteratively based on fit and relationship to the construct. The subjects were predominately male (63%) aged on average 68-years-old. A 12-item unidimensional functioning measure was developed. All items and persons fit the Rasch model with stable item-person reliability indices of 0.98 and 0.91, respectively. Item precision (standard errors) ranged from 0.14-0.37 logits. Gaps in measurement occurred at the extremes of the measure and there was a small ceiling effect. A 12-item measure captured the concept of functioning that could be used as a prototype to quantify recovery post-stroke. These items could form the basis for a measure of functioning.