Objective: To establish the concurrent validity of the Health Assessment Questionnaire (HAQ) Disability Index in systemic sclerosis (SSc; scleroderma).
Methods: Eighty subjects with SSc completed the HAQ Disability Index questionnaire. An occupational therapist, who was blind to the subjects' responses, observed each subject's performance on 10 of the items.
Results: Paired t-tests showed significant differences between the observer and subjects' responses for tying shoes, buttoning, gripping, and walking. Intra-class correlations between observer and subjects ranged from 0.38 to 0.76.
Conclusion: The results support the validity of the HAQ Disability Index in patients with systemic sclerosis.