Association of anxiety disorders with the risk of smoking behaviors: a meta-analysis of prospective observational studies.

OBJECTIVE: Published articles reported controversial results about the association of anxiety disorders with the risk of smoking behaviors. A meta-analysis was performed to assess this association between anxiety disorders and smoking behaviors. METHODS: A comprehensive search was performed to identify prospective observational studies (from January, 1990 to March, 2014) of the aforementioned association. The Q test and I(2) statistic were used to examine between-study heterogeneity. Fixed or random effect model was selected based on heterogeneity test among studies. Meta-regression and the "leave one out" sensitive analysis were used to explore potential sources of between-study heterogeneity. Publication bias was estimated using Egger's regression asymmetry test. RESULTS: Fifteen articles were included. After excluding studies that were the key contributors to between-study heterogeneity, the meta-analysis showed a significant association of anxiety disorders with increased risk of regular smoking (OR = 1.41, 95% CI: 1.23-1.62) and nicotine dependence (OR = 1.58, 95% CI: 1.45-1.73). No significant influence and publication bias were observed both before and after excluding the key contributors to heterogeneity. CONCLUSION: This meta-analysis suggested that anxiety disorders had significant positive effect on the risk of smoking behaviors. This association needs to be confirmed by further studies.