Evaluation of a smoke-free beaches intervention in Barcelona: A quasi-experimental study

Background We aim to assess the effect of a smoke-free beaches (SFB) intervention in Barcelona on smoking during the 2021 bathing season. Methods Quasi-experimental pre-post design (pre-intervention period: 15-28 May; post-intervention period: 29 May-12 September). Based on users' profiles and location, four beaches were assigned to the intervention group (IG) and five to the comparison group (CG). The intervention involved: a mayoral decree (29 May), a communication campaign and beach on-site information. We established two 3 m × 3 m transects per beach from the coastline to the promenade. Trained teams collected smoking-related information in the transects through observations and surveys to beach users. Outcomes are as follows: percentage of people reporting witnessing smoking behaviours the last fortnight and percentage of people observed smoking. We calculated and compared prevalence ratios (PRs) with adjusted Poisson regressions. Results 3751 interviews (1721 IG; 2030 CG) and 1108 observations (498 IG, 610 CG) were carried out. SFB were associated with a significant reduction in the percentage of people reporting witnessing smoking (IG (pre: 87.2%; post: 49.7%); CG (pre: 86.2%; post: 74.1%); PR (95% CI): 0.7 (0.6 to 0.8)); and in the users observed smoking in the beach (IG (pre: 3.8%; post: 3.0%); CG (pre: 2.3%; post: 9.9%); PR (95% CI): 0.3 (0.3 to 0.4)). Satisfaction scores were 8.3 (IG) and 8.1 (CG) out of 10. Conclusion An SFB intervention is an effective and well-accepted measure to reduce smoking and smokers' visibility. Smoke-free measures should be extended to beaches and other non-regulated outdoor areas.