How to measure health status in rheumatoid arthritis in non-English speaking patients: validation of a Spanish version of the Health Assessment Questionnaire Disability Index (Spanish HAQ-DI).

The HAQ-Disability Index (HAQ-DI) is a useful instrument to measure health status in rheumatoid arthritis (RA) patients. Translation into another language requires a validation process, however. We have translated the HAQ-DI to be used on Spanish-speaking populations. We administered the questionnaire to 97 RA patients during the course of routine medical care. Reliability, measured by a test-retest with a one-month interval, was high (Spearman's rho = 0.89). Convergent and construct validity was obtained for all comparisons (Pearson's r > 0.4). The instrument was sensitive in detecting clinical improvement. We conclude that the Spanish HAQ-DI retains the characteristics of the original index and can be used to assess outcome in Spanish-speaking patients with RA. The procedure described may be used to translate the instrument into other languages either directly from English or from the Spanish version presented here.