Impact of smoke-free legislation on stroke risk: A systematic review and meta-analysis.

Purpose: Secondhand smoke significantly increases the risk of cerebrovascular diseases, prompting recent public smoking bans. We aimed to ascertain the effects of smoke-free legislation on stroke incidence and mortality.

Methods: We systematically searched Medline, Embase, Cochrane Library, and Scopus up to August 13, 2023, for studies reporting changes in stroke incidence following partial or comprehensive smoking bans. A random-effects meta-analysis was conducted on hospital admissions and mortality for stroke, stratified based on comprehensiveness of the ban ((i) workplaces-only, (ii) workplaces and restaurants, (iii) workplaces, restaurants and bars). The effect of post-ban follow-up duration was assessed visually by a forest plot, while meta-regression was employed to evaluate for any dose-response relationship between ban comprehensiveness and stroke risk.

Findings: Of 3987 records identified, 15 studies analysing bans across a median follow-up time of 24 months (range: 3-67) were included. WRB bans were associated with reductions in the rates of hospital admissions for stroke (nine studies; RR, 0.918; 95% CI, 0.872-0.967) and stroke mortality (three studies; RR, 0.987; 95% CI, 0.952-1.022), although the latter did not reach statistical significance. There was no significant difference in the risk of stroke admissions for studies with increased ban comprehensiveness and no minimum duration for significant post-ban effects to be observed.

Discussion and conclusion: Legislative smoking bans were associated with significant reductions in stroke-related hospital admissions, providing evidence for its utility as a public health intervention.