Translation and validation of the Malay version of Shiffman-Jarvik withdrawal scale and cessation self-efficacy questionnaire: a review of psychometric properties

BACKGROUND Smoking tobacco is a major concern in Malaysia, with 23.1% of Malaysian adults smoking tobacco in 2012. Withdrawal symptoms and self-efficacy to quit smoking have been shown to have significant effects on the outcomes of smoking cessation. The Shiffman-Jarvik Withdrawal Scale (Psychopharmacology, 50: 35-39, 1976) and the Cessation Self-Efficacy Questionnaire (Cognitive Ther Res 5: 175-187, 1981) are two questionnaires that have been widely used in various smoking cessation research. The short SJWS consists of 15 items with five subscales: physical symptoms, psychological symptoms, stimulation/sedation, appetite, and cravings. The CSEQ is a 12-item questionnaire that assesses participant's self-efficacy to avoid smoking in various situations described in each item. The aim of this study was to translate and validate the Malay language version of the SJWS and the CSEQ. METHODS The SJWS and CSEQ were translated into the Malay language based on the back translation method. A total of 146 participants (25.08 ± 5.19 years) answered the translated questionnaires. Psychometrics properties such as reliability (internal consistency and test-retest) and validity (content validity, construct validity and face validity) were examined. RESULTS Both questionnaires showed acceptable internal consistency; SJWS-M (α = 0.66) and CSEQ-M (α = 0.90) and good test-retest reliability; SJWS-M (r = 0.76) and the CSEQ-M (r = 0.80). SJWS-M (χ(2) = 15.964, GFI = 0.979, CFI = 1.000, RMSEA = 0.000, ChiSq/df = 0.939, AGFI = 0.933, TLI = 1.004, and NPI = 0.978) and CSEQ-M (of χ(2) = 35.16, GFI = 0.960, CFI = 0.999, RMSEA = 0.015, ChiSq/df = 1.034, AGFI = 0.908, TLI = 0.999, and NPI = 0.979) also showed good construct validity. Both questionnaires showed sufficient item to item convergent validity and item discriminant validity. Content validity was established (reassess) by experts in the field of psychology, culture and language whereas face validity was confirmed by smokers. CONCLUSIONS The translated Malay version of the CSEQ-M and the SJWS-M showed great reliability and validity evidences therefore is an adequate and useful instrument to evaluate Malaysian smokers. Future studies could investigate differences in self-esteem between long-term and short-term smokers and evaluate the usability of these questionnaires in local smoking research and other Malay speaking countries (Brunei and Indonesia).