Objective: To construct a functional disability scale for the rheumatoid hand and to determine if this scale also assesses functional handicap.
Methods: Outpatients and inpatients with rheumatoid arthritis (RA) according to the ACR criteria answered a set of questions on their daily hand activities. Intrarater and interrater reliability were examined. Criterion referenced validity, and convergent and divergent validities were investigated. Factor analysis followed by varimax rotation was performed. Spearman's (rs) correlation coefficients between 2 quantitative variables were examined. The level of significance was p < 0.05.
Results: 96 patients with RA were recruited. The provisional scale had 41 questions. The elimination process left 18 hand activity questions with 6 levels of answers. The intrarater and interrater reliabilities of the scale were 0.97 and 0.96, respectively. Correlation of the scale's total score with visual analog scale (VAS) measure of functional handicap (rs = 0.78) showed good criterion referenced validity. The scale had good convergence with Revel's Functional Index (rs = 0.91) and a moderate relation to the Hand Functional Index (HFI) (rs = 0.58). The scale had a moderate, fair, or no relation to age, morning stiffness, pain measures, and hand swelling. The scale had 3 main factors by factor analysis. An English translation of the scale was validated.
Conclusion: We have developed a practical functional disability scale for rheumatoid hands that also assesses functional handicap. It has 18 hand activity questions and has been validated in a French population.