Impact of a smoke-free policy on smoking prevalence on hospital grounds: A before-after study

INTRODUCTION: Studies on the impact of smoke-free policies (SFPs) on hospitals grounds on on-site smoking are scarce. On 1 October 2019, an SFP was implemented on the grounds of the Amsterdam UMC hospital in the Netherlands, including measures for sustained enforcement. This study assessed the impact of this SFP on smoking prevalence on hospital grounds up to 18 months after implementation. METHODS: Observations were systematically conducted 7 weeks before and after the SFP was implemented, and at 5 and 18 months afterwards. A total of 32 sites were included in the study, divided over two hospital locations. On each site, the number of smokers was systematically observed and categorized into staff, patient, student, or visitor. Smoking prevalence on hospital grounds was calculated by the number of observed smokers as a proportion of all people observed. Bubble maps were created to visualize changes in the geographical distribution of smokers. RESULTS: Smoking prevalence on hospital grounds decreased significantly from 17.4% before to 3.3% after implementation of the SFP. Following implementation, the largest decrease was observed in smoking among staff (-96.7%) and patients (-92.3%). The decrease in smoking prevalence was sustained 18 months after implementation (5.0%). The number of smokers decreased on nearly all sites. CONCLUSIONS: The substantial and sustained decrease in smoking prevalence found in this study highlights the potential of SFPs on hospital grounds to protect people from exposure to (secondhand) smoking. Continued enforcement of these SFPs seems essential to ensure ongoing compliance.