Validity and responsiveness of the Rehabilitation Activities Profile (RAP) in patients with rheumatoid arthritis

Abstract

Objective: To investigate the internal consistency, validity and responsiveness of the Rehabilitation Activities Profile (RAP; a rehabilitation tool structuring the multidisciplinary team care process) in patients with rheumatoid arthritis. Methods: In 85 rheumatoid arthritis patients admitted to a rheumatology clinic the RAP was applied at admission, at discharge, and six weeks thereafter. Additional assessments included measures of physical and psychological functioning, disease activity and quality of life. The internal consistency of the RAP was determined with Cronbach's alpha. Associations between the RAP and other outcome measures were determined by Spearman rank correlation coefficients. Responsiveness measures included the standardized response mean (SRM), effect size (ES) and responsiveness ratio (RR). Results: Cronbach's alpha of the RAP total score was 0.78. The RAP total score correlated significantly with all other outcome measures. The mean RAP total score improved from 15.2 to 13.2 at discharge (change -2.0; 95% confidence interval (CI) -3.4 to -0.7) and to 11.5 (change -3.7; 95% CI -3.9 to -1.5) six weeks thereafter. The responsiveness of the RAP total score was low (standardized response mean -0.34, effect size -0.30) to high (responsiveness ratio -0.87) at discharge and moderate (standardized response mean -0.54, effect size -0.55) to high (responsiveness ratio -1.56) six weeks thereafter. Conclusions: The RAP appeared to be an internally consistent, valid and responsive measure to reflect limitations on the level of activities and participation in patients with rheumatoid arthritis admitted for multidisciplinary team care.