Prevalence of cigarette smoking among college students in Iran: An updated systematic review and meta-analysis of observational studies.

Background: Cigarette smoking is known as a gateway drug for illicit drug use in youth. The objective of this study is to assess the prevalence of cigarette smoking in the college students in Iran. Methods: We searched electronic databases including Scopus, Medline/PubMed, Google Scholar and Web of Science, and national databases such as Magiran, Scientific Information Database, Iranmedex, Medlib, Irandoc, and IranPsych from 1946 to 21st July 2018 without any language restriction using a proper search strategy. We used a random effect model to calculate the pooled prevalence of cigarette smoking in college students in Iran. Chi-square test and I2 index were used to evaluate the heterogeneity between the studies. We used the meta-regression and subgroup analysis to assess the potential source of heterogeneity. Stata software, version 11 (StataCorp, TX) was used for all statistical analysis. Results: We included 60 eligible articles in our study. The pooled prevalence of cigarette smoking at least once in the lifetime was 19% (95%CI: 17-22). The I2 index indicated considerable between-study heterogeneity (I2 =98%, p<0.001). The pooled prevalence of cigarette smoking at least once in the lifetime in males and females was 28% (95% CI: 23-34) and 9% (95% CI: 6-13), respectively. In multivariable meta-regression, a significant association was shown between the year of study (β=-13.1, p=0.011) and sampling method (β=-12.8 p=0.017) and daily use in the last month. Conclusions: Increasing prevalence of smoking among Iranian university students is an important health priority. Increasing preventive and health education programs are recommended.