Linguistic validation and cultural adaptation of an English version of the Evaluation of Daily Activity Questionnaire in rheumatoid arthritis

BACKGROUND: To linguistically validate and culturally adapt the Evaluation of Daily Activity Questionnaire (EDAQ) for use in rheumatoid arthritis (RA) from Swedish to British English. The EDAQ is a patient reported outcome measure of daily activity ability. It includes 11 activity domains (Eating and Drinking; Personal Care; Dressing; Bathing; Cooking; Moving Indoors; House Cleaning; Laundry; Moving and Transfers; Communication; Moving Outdoors) and was developed for use in rheumatoid arthritis (RA). METHODS: The EDAQ was translated from Swedish to English using standard methods. Activity diaries, cognitive debriefing interviews and focus groups were completed with people with RA to: generate new culturally applicable items; identify important items in the Swedish version to retain in the English version; and develop the English EDAQ based on their views of content and layout. Content validity was established by linking the EDAQ to the International Classification of Functioning RA Core Set. RESULTS: The English EDAQ translation was harmonized with the Swedish version to ensure equivalence of meaning. Sixty-one people with RA participated. 156 activities were identified from 31 activity diaries and included in a draft English EDAQ. Following interviews (n = 20) and four focus groups, 138 activities were retained and three additional domains added (Gardening/Household Maintenance; Caring; and Leisure/Social Activities). Most ICF RA Core Set activities are in the EDAQ. CONCLUSIONS: The English EDAQ is a detailed self-report measure of ability in RA with good content validity. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s12955-014-0143-y) contains supplementary material, which is available to authorized users.