DISABILITY OF THE ARM, SHOULDER AND HAND QUESTIONNAIRE IN SWEDISH PATIENTS WITH RHEUMATOID ARTHRITIS: A VALIDITY STUDY

Objective: The aim of this study was to assess the reliability and validity of the Disability of the Arm, Shoulder and Hand (DASH) questionnaire in a Swedish rheumatoid arthritis population. Methods.: To investigate the concurrent and convergent validity, 67 patients with rheumatoid arthritis completed the DASH, the Health Assessment Questionnaire Disability Index (HAQ) and activity-induced pain. Active shoulder-arm motion, handgrip force and disease activity (Disease Activity Score in 28 joints; DAS28) were assessed. The test-retest reliability was investigated in 26 patients. Face validity was also investigated. Results: Spearman's correlation coefficient revealed a significant association (p<0.00I) between the DASH score and HAQ index (r(s) 0.80), confirming satisfactory concurrent validity. A significant association (p <= 0.02) was found between the DASH score and active shoulder-arm motion (r(s) -0.38 to -0.50), handgrip force (r(s) -0.46 to -0.59), activity-induced pain (r(s) 0.66) and DAS28 (r(s) 0.63), confirming satisfactory convergent validity for the DASH questionnaire. Satisfactory test-retest reliability (intraclass correlation coefficient 0.99, 95% confidence interval 0.98-0.99) and face validity of the questionnaire were confirmed. Conclusion: The DASH questionnaire showed satisfactory test-retest reliability, concurrent-, convergent-, and face validity for patients with rheumatoid arthritis and can be recommended for use in rheumatoid arthritis populations.