Smoking and Idiopathic Pulmonary Fibrosis: A Meta-analysis

Abstract Introduction In this study, we aimed to systematically explore the relationship between smoking and idiopathic pulmonary fibrosis (IPF). Aims and Methods The PubMed, Web of Science, and Embase databases were searched to systematically identify eligible studies. The Newcastle‒Ottawa Quality Assessment Scale (NOS) was used to evaluate the quality of the selected studies. The pooled odds ratio (OR) and survival hazard ratio (HR) were calculated with a random effects model using Stata 16.0 software. Results Thirty studies were enrolled. All of the included studies were considered to have intermediate or high quality. Nine studies were suitable for meta-analysis of ORs, and 21 studies were suitable for meta-analysis of survival HR. The pooled analysis revealed a significant difference in the risk of IPF between the smoking group and the never-smoking group (OR 1.71, 95% CI: 1.27 to 2.30, p