Systematic review and meta-analysis of the association between smoking and the incidence of frailty

Background and objective Cigarette smoking is one of the main causes of health problems in the world and can also lead to an increased risk of frailty. Our goal is to perform a systematic review and meta-analysis of the relationship between smoking and frailty. Methods Researchers searched PubMed, Scopus, Google Scholar and Research Gate by using keywords through December 2018. Eligible articles were merged and a meta-analysis was conducted using the random effects method. Finally an analysis was done based on smoking status, and publication bias was assessed as well. Results The population analyzed comprised 61,905 people. The risk ratio (RR) of frailty based on smoking was 1.22 with a confidence interval (CI) of 1.12-1.33 (p<0.001). In current smokers, the RR was 1.63 (p<0.001). No significant difference was found in former smokers. The results indicated a publication bias in the studies included into the meta-analysis. Discussion Smoking increases the risk of disability; therefore, the provision of cigarette smoking cessation treatment can reduce this risk. As the results also showed, former smokers are less likely to be frail.