Modified Reasons for Smoking Scale: translation to Portuguese, cross-cultural adaptation for use in Brazil and evaluation of test-retest reliability.

OBJECTIVE To translate the Modified Reasons for Smoking Scale (MRSS) to Portuguese, to submit it to cross-cultural adaptation for use in Brazil and to evaluate the test-retest reliability of the translated version. METHODS An English-language version of the MRSS was translated to Portuguese by Brazilian doctors who have thorough knowledge of the English language. A consensus version was produced by a multidisciplinary group including two pulmonologists, a psychiatrist and a psychologist. This version was back-translated to English by an American translator. Cross-cultural adaptation of the final version was evaluated in a sample of 20 healthy smokers. Test-retest reliability was evaluated by applying the translated version of the scale in 54 healthy smokers on two distinct occasions, 15 days apart. RESULTS This translated version of the MRSS was well understood by 95% of the smokers, indicating excellent cross-cultural equivalence. The degree of reliability of the answers in two different occasions was almost perfect for two questions, substantial for ten questions, moderate for eight questions, and low for one question. The intraclass correlation coefficients of the motivational factors obtained on the two different occasions, calculated according to previously published theoretical models, were higher than 0.7 for six of the seven subscales. CONCLUSIONS The Portuguese-language version of the MRSS shows satisfactory cross-cultural equivalence and test-retest reliability. It can be a useful tool in the evaluation and treatment of smokers in Brazil.