The Rheumatoid Arthritis Quality of Life (RAQoL) for Sweden: adaptation and validation.

OBJECTIVE: To produce and evaluate the official Swedish language version of the Rheumatoid Arthritis Quality of Life instrument (RAQoL).
METHODS: The UK RAQoL was translated into Swedish by a bilingual translation panel. A separate lay panel was conducted to consider the appropriateness and comprehensibility of the items in Swedish. Interviews were conducted with 15 Swedish RA patients to assess face and content validity. Responses to a postal survey were used to calculate reproducibility and construct validity.
RESULTS: Few difficulties arose in the translation process and the new language version was well received by the lay panel and field-test participants. One hundred and sixty-five RA patients participated in the postal survey (69% female; mean age 62.7 years, SD 11.3, RA duration range 1-62 years). Cronbach's alpha for the Swedish RAQoL was 0.91 and test-retest reliability was 0.95, indicating that the instrument has adequate inter-relatedness of items and very low inherent random measurement error. A high correlation with the Health Assessment Questionnaire (HAQ) was observed; this was expected because RA has significant physical manifestations that are in turn a significant determinant of QoL. The Swedish RAQoL was able to distinguish between patients who differed according to their self-perceived RA severity, general health, and rating of their RA today, in addition to whether or not the patient was experiencing a flare of RA.
CONCLUSIONS: The official Swedish RAQoL was well received by RA patients. The psychometric quality of the adapted questionnaire means that it is suitable for inclusion in clinical trials involving patients with RA.