First Stage; Translation/back-translation process

In this section the English version of the questionnaire was translated into Persian by two mastered translators and was translated back to English after consulting with some professors and a third person who had total experience of both languages. To finalize the adaptation, item clarity, content validity, and length of the questionnaire, a pilot study was carried out with the translated and revised tools that consisted of two steps: at first, tools were submitted by ten academic experts who were specialist in the internal diseases, psychology, behavior change, health education and promotion. The experts rated relevance of each question on a Likert type ordinal scale (1 = not relevant to 4 = very relevant). In this section, the minimum value for content validity index (CVI) and content validity ratio (CVR) were considered 0.79 and 0.62, respectively (Knapp and Brown, 1995). Then pilot study was done among 20 subjects who were similar to study population to assess respondent comprehension and the feasibility of the instruments. The measurement of item impact indicator concerning all the sentences was lower than 1.5 and none of the options were excluded.