Fig. 9
From: Association of electronic cigarette use and risk of COPD: a systematic review and meta-analysis

Funnel plot analysis of pooled OR showing the association between current e-cigarettes users and greater odds of having COPD.
From: Association of electronic cigarette use and risk of COPD: a systematic review and meta-analysis
Funnel plot analysis of pooled OR showing the association between current e-cigarettes users and greater odds of having COPD.