Rheumatoid arthritis is a chronic systemic disease that causes joint damage. A variety of methods have been used to evaluate the general health status of these patients but few have specifically evaluated the hands. The objective of this study was to translate, perform cultural adaptation and assess the validity of the Michigan Hand Outcomes Questionnaire for Brazil.
Validation study conducted at a university hospital in Curitiba, Brazil.
Firstly, the questionnaire was translated into Brazilian Portuguese and back-translated into English. The Portuguese version was tested on 30 patients with rheumatoid arthritis and proved to be understandable and culturally adapted. After that, 30 patients with rheumatoid arthritis were evaluated three times. On the first occasion, two evaluators applied the questionnaire to check inter-rater reproducibility. After 15 days, one of the evaluators reassessed the patients to verify intra rater reproducibility. To check the construct validity at the first assessment, one of the evaluators also applied other similar instruments.
There were strong inter and intra rater correlations in all the domains of the Michigan Hand Outcomes Questionnaire. Cronbach's alpha was higher than 0.90 for all the domains of the questionnaire, thus indicating excellent internal validity. Almost all domains of the questionnaire presented moderate or strong correlation with other instruments, thereby showing good construct validity.
The Brazilian Portuguese version of the Michigan Hand Outcomes Questionnaire was translated and culturally adapted successfully, and it showed excellent internal consistency, reproducibility and construct validity.