Psychometric evaluation of a Moroccan version of health assessment questionnaire for use in Moroccan patients with rheumatoid arthritis.

Objective of the study is to test the reliability and validity of a translated version of health assessment questionnaire (HAQ) on Moroccan patients with rheumatoid arthritis (RA). We led a prospective study from July 2004 to September 2005. A total of 100 Moroccan patients were recruited. After translation to dialect Arabic, back translation, expert committee review and pretesting of the questionnaire, it was administered to the selected patients and tested for construct validity, reliability and internal consistency. The construct validity was evaluated by correlating the yield of the questionnaire with other disease activity and severity parameters. The questionnaire was administered again after a time interval of between 2 and 10 days for evaluation of the reliability of this test. All the items were tested for their loyalty to the principal component. The adapted questionnaire showed a good internal consistency. Cronbach's alpha test was 0.994. The test-retest showed a strong reliability with a kappa test ranging from 0.70 to 0.92 for all domains. Intraclass correlation coefficient for the total score was 0.987. The Moroccan HAQ showed a strong validity. It correlates significantly with disease activity and severity parameters. The unidimentionality has been demonstrated. About 71.5% of all variabilities was accounted for by the first principal component. The Moroccan Arabic dialect version of HAQ is a reliable and valid instrument that can be self-administered by Moroccan RA patients to assess their functional disability.