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.

Keywords: Smoking cessation; Scales; Translations; Validation studies.

Objective: To develop a new scale aimed at evaluating smoking motivation by incorporating questions and domains from the 68-item Wisconsin Inventory of Smoking Dependence Motives (WISDM-68) into the Modified Reasons for Smoking Scale (MRSS). Methods: Nine WISDM-68 questions regarding affiliative attachment, cue exposure/associative processes, and weight control were added to the 21 questions of the MRSS. The new scale, together with the Fagerström Test for Nicotine Dependence (FTND), was administered to 311 smokers (214 males; mean age = 37.6 ± 10.8 years; mean number of cigarettes smoked per day = 15.0 ± 9.2), who also provided additional information. We used exploratory factor analysis in order to determine the factor structure of the scale. The influence that certain clinical features had on the scores of the final factor solution was also analyzed. Results: The factor analysis revealed a 21-question solution grouped into nine factors: addiction, pleasure from smoking, tension reduction, stimulation, automatism, handling, social smoking, weight control, and affiliative attachment. For the overall scale, the Cronbach's alpha coefficient was 0.83. Females scored significantly higher for addiction, tension reduction, handling, weight control, and affiliative attachment than did males. The FTND score correlated positively with addiction, tension reduction, stimulation, automatism, social smoking, and affiliative attachment. The number of cigarettes smoked per day was associated with addiction, tension reduction, stimulation, automatism, affiliative attachment, and handling. The level of exhaled CO correlated positively with addiction, automatism, and affiliative attachment. Conclusions: The new scale provides an acceptable framework of motivational factors for smoking, with satisfactory psychometric properties and reliability.

Keywords: Smoking; Validation studies; Tobacco use cessation.