Adaptation and validation of the rheumatoid arthritis quality of life scale for use in Canada.
OBJECTIVE
The Rheumatoid Arthritis Quality of Life questionnaire (RAQoL) was developed simultaneously in the UK and the Netherlands to measure quality of life in patients with RA. We adapted and validated the RAQoL for the English-Canadian and French-Canadian languages and culture.


METHODS
The UK RAQoL was translated into French-Canadian by a bilingual translation panel. Separate lay panels were then used to ensure that this and the English-Canadian instruments were appropriate for use with Canadian patients. Interviews were conducted with 15 French-Canadian and 15 English-Canadian patients with RA to determine the content validity. Reliability and construct validity were established by means of test-retest mail surveys conducted with 92 French-Canadian and 87 English-Canadian RA patients. The survey consisted of the adapted RAQoL, the Health Assessment Questionnaire (HAQ), and a demographic questionnaire.


RESULTS
The RAQoL was successfully adapted for both the French and English-Canadian cultures. Field testing showed both versions to be well received by respondents. Of the French-Canadian patients included in the postal survey, 52 responded at Time 1 and 50 at Time 2. For the English-Canadian sample, 54 responded at both time points. Missing data rates for the RAQoL were low and floor and ceiling effects were minimal. Test-retest reliability was good for both versions: 0.87 for the French-Canadian and 0.95 for the English-Canadian. Alpha coefficients (0.92 for the French-Canadian, 0.93 for the English-Canadian) showed the items to be adequately interrelated and scores on the measure showed moderate to high correlations with the HAQ, confirming construct validity. Both versions of the RAQoL were also able to distinguish patient groups that differed according to perceived health status and perceived severity of RA. In addition, the French-Canadian version was able to distinguish patients who rated today as bad or very bad from those who rated today as good or very good.


CONCLUSIONS
The new versions of the RAQoL were well received by both French and English speaking Canadians. The psychometric quality of the adapted questionnaires means they are suitable for inclusion in clinical trials involving patients with RA.
Neville
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C
Division of Clinical Epidemiology, McGill University Health Centre, Montreal, Quebec, Canada.
Whalley
D
D
McKenna
S
S
Le Comte
M
M
Fortin
P R
PR
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001172:Arthritis, Rheumatoid / Q000523:psychology*; D002170:Canada; D005260:Female; D006304:Health Status; D006306:Health Surveys; D006801:Humans; D008297:Male; D008875:Middle Aged; D019303:Multilingualism; D011788:Quality of Life; D015203:Reproducibility of Results