This cross-sectional descriptive-analytic study was done during year 2014 on tenth-, eleventh- and twelfth-year high school students residing in Birjand, Iran. As a similar study on the relationship between social capital and lifestyle in Iran could not be found, a pilot study was done and the results were used for sample size calculation. Consequently, 400 students were found to be needed for the study (α = 0.05; δ = 10.64; and d = 0.1 δ). Students were selected via stratified random sampling. Accordingly, Birjand city was divided to 4 geographical regions, namely north, east, south, and west. Then, a boys’ and a girls’ high school were randomly selected from each region. Afterwards, a predetermined proportion of students were randomly selected from each educational grade. Students were recruited if they were willing to participate, gave informed consent for participation, and lived with both of their parents.
Study data were collected via a demographic questionnaire, the social capital index, and the adherence to a healthy lifestyle questionnaire. The demographic questionnaire included items such as age, gender, educational grade, and parents’ educational status and income.
Social capital index (SCI) was developed during year 2014 by Beilmann et al. (
19). It includes 26 items in 4 main dimensions, namely parental acceptance-rejection (10 items), intimacy with parents (3 items), admiration by parents (3 items), and peer acceptance (10 items). The items of the first dimension are scored from 1 (Never) to 4 (Always), while the items of the second and the third dimensions are scored from 1 (Never) to 5 (Always). Finally, the items of the fourth dimension are scored from 1 (completely disagree) to 5 (completely agree). Thus, the total SCI score would be 26 to 120, which was interpreted in the present study as follows; 26 to 57: poor social capital; 58 to 90: moderate social capital; and 91 to 120: good social capital. For the purposes of the present study, SCI was initially translated from English to Persian by 2 independent translators. Then, the 2 translations were compared and a single Persian translation was generated. After that, the Persian SCI was back-translated to English by another translator. The English SCI and the original SCI were compared, discrepancies were resolved, and necessary amendments were made to the Persian SCI. The content validity of the Persian SCI was assessed through content validity index (CVI) calculation. Accordingly, 6 experts were asked to comment on the relevance of each SCI item on a 4-point scale as follows: “Irrelevant”: 1; “somehow relevant”: 2; “relevant”: 3; and “completely relevant”: 4. Then, the CVI of each item was calculated via dividing the number of experts, who rated that item as either 3 or 4, by the total number of all experts, i.e. 6. As indicated by previous studies, when the number of experts was 6 or more, the minimum acceptable CVI was 0.78 (
20,
21). The CVI values in the present study were 0.83 to 1. Moreover, the total CVI value was 0.93. The reliability of SCI was assessed using the test-retest stability technique. Consequently, thirty students, who were not included in the study yet met the inclusion criteria, were asked to complete SCI twice with a 2-week interval. The test-retest Pearson correlation coefficient was 0.91, denoting acceptable SCI stability. The Cronbach’s alpha of SCI and its dimensions were 0.83 and 0.66 to 0.90, respectively.
Adolescent healthy lifestyle questionnaire (AHLQ) was developed in 2012 by Taymoori et al. (
22) based on the items of the existing questionnaires in the area of lifestyle and health-promoting behaviors, such as the health-promoting lifestyle profile II (
23). The AHLQ consists of 36 items, which are scored from 1 (Never) to 5 (Always). The 6 dimensions of AHLQ include nutrition (6 items), physical activity (6 items), health responsibility (8 items), stress management (4 items), social support (5 items), spiritual growth and self-actualization (7 items). The total score of AHLQ could range from 36 to 180 and is interpreted as unhealthy (a score of 36 to 84), moderately healthy (a score of 85 to 133), and healthy (a score of 134 to 180) lifestyle (
24). Taymoori et al. (2012) used AHLQ to assess the health-promoting lifestyle of a group of Iranian adolescents and reported a Cronbach’s alpha of 0.82 (
22).
This study was approved by the institutional review board and the research ethics committee of Birjand University of Medical Sciences, Birjand, Iran, with codes of 53.93 and IR.BUMS.REC.1394.401, respectively. Before referring to the study settings, necessary permissions were obtained from the institutional review board of the university, Birjand department of education, and the administrators of the high schools. The reserachers then referred to the selected high schools, recruited eligible students, and asked them to complete the data collection tools. Students were informed that participation was voluntary and the data would be managed confidentially. Data collection lasted for 2 weeks.
The data were entered in the SPSS software (v. 16). Normality testing was performed using the Kolmogorov-Smirnov test. The results of the test showed that the scores of AHLQ and its health responsibility and physical activity dimensions were distributed normally (P > 0.05). However, the scores of the other 4 dimensions, i.e. spiritual growth and self-actualization, social support, nutrition, and stress management, as well as the scores of SCI and all its dimensions were distributed non-normally (P < 0.05). Descriptive statistics measures, such as frequency, mean, and standard deviation, were used to describe the data. Moreover, statistical tests and methods, such as Pearson and Spearman correlation analyses, one-way analysis of variance, and independent-sample t, Mann-Whitney U, and Kruskal-Wallis tests were performed for data analysis. Stepwise multiple linear regression analysis was done to predict lifestyle, based on social capital and demographic characteristics. The level of significance was less than 0.05.