3.2. Instruments and Measures
A self-administered questionnaire, the health-promoting lifestyle profile II (HPLP II) questionnaire, and five standard instruments regarding Pender models’ constructs, including perceived health status, perceived benefits, perceived barriers, social support, and self-efficacy, were used to collect data. All instruments were first translated by the primary investigator and then a bilingual person translated them back to English; all differences were improved. The translated instruments were reviewed by a group of Iranian health education experts, and minor amendments were made to them. Prior to data collection, the questionnaires were tested for reliability in a sample of 50 chemical veterans. In this study, all questionnaires were reliable and the ranges of Cronbach’s alpha coefficients were 0.82 (perceived health status)–0.92 (HPLP II).
The self-administered questionnaire queried age, gender, occupation, disability, type of injury, and militancy type.
The HPLP II included 52 questions, and all items are scored using a Likert scale ranging from 1 (never) to 4 (always). Therefore, the total questionnaire score ranges between 52 and 208. This standard questionnaire for measuring health-promoting behaviors includes six dimensions, namely, health responsibility, physical activity, nutrition, spiritual growth, interpersonal relations, and stress management. Higher scores indicate more favorable conditions in veterans in terms of health-promoting behaviors. Walker and collogues reported Cronbach’s alpha of 0.94 for this instrument (13-15). In this study, for this instrument, we obtained Cronbach’s alpha of 0.92, and content validity index (CVI) values in terms of simplicity, precision, and specificity were 0.91, 0.97, and 0.91, respectively.
The perceived health status questionnaire is a 12-item scale covering physical and mental health. Response categories for items vary from 2- to 6- point scales, and raw scores for items range from 1 to 6. Physical domain scores range from 6 to 20, and mental domain scores range from 6 to 27. Montazeri et al. reported Cronbach’s alpha of 0.73 for the physical health subscale and 0.72 for the mental health subscale in Iranian people. Furthermore, explanatory factor analysis (16) and confirmatory factor analysis (CFA) indicated good fit validity for this tool (17). Given these previous evaluations of this questionnaire in Iran, we did not validate it in the present study.
The standard multidimensional scale of perceived social support contains 12 items and assesses three subscales, namely, family, friends, and other significant individuals’ support. The items are scored on a 7-point Likert scale ranging from strongly disagree (1 point) to strongly agree (7 points), and the total questionnaire score ranges from 12 to 84. Psychometric studies have indicated good reliability (α = 0.91). Moreover, Cronbach’s alpha coefficient of this scale was 0.94, which indicates good internal consistency (18). In this study, the CVI values for simplicity, precision, and specificity were 0.93, 0.96, 0.91, respectively, and Cronbach’s alpha was 0.87, for this instrument.
The scales regarding perceived benefits of and perceived barriers to health-promoting behaviors comprised 26 and 18 questions, respectively. The items of these questionnaires were evaluated on a 3-point Likert scale. Cronbach’s alpha for the benefits and barriers scales were 0.82 and 0.60, respectively (10). The CVI values for simplicity, precision, and specificity for the perceived benefits questionnaire were 0.99, 0.96, and 0.99, respectively, while those for the perceived barriers questionnaire were 0.98, 0.98, and 0.91. Furthermore, the reliability scores of the benefits and barriers scales were 0.91 and 0.88, respectively, in this study.
Perceived self- efficacy has been defined as people’s judgments on their own possibilities for indulging in health-promoting behaviors. Becker et al. designed this scale for measuring six dimensions of health-promoting behaviors. The 26 items comprising this questionnaire are scored on a 4- point Likert scale from never (1 point) to always (4 points) with the total score ranging from 26 to 104. This scale had a Cronbach’s alpha of 0.92 (19). Its CVI values for simplicity, precision, and specificity were 0.99, 0.98, and 0.98, respectively, which indicate its appropriateness of content validity. The reliability score of this scale was obtained as 0.90.