Mass media campaigns to increase the use of bicycle helmets: A systematic review and meta-analysis

Background: Bicycle helmets protect against serious brain injuries caused by bicycle accidents. One strategy to increase helmet use is via mass media campaigns. This study systematically reviewed the effectiveness of mass media campaigns which aimed to increase bicycle helmet use. Methods: The following electronic databases were systematically searched between January 2000 and February 2022: PubMed/Medline, Scopus, Web of Science (WOS), and others including the Transportation Research Information Service and International Transport Research Documentation. Inter-study heterogeneity was assessed using Chi-Squared and I2 tests and a random effects model was applied to pool the Odd Ratios (ORs). Findings: Only eight articles were found to be eligible for this meta-analysis. Using a random effects model, the pooled results showed statistically significant increases in helmet use among bicyclists (OR = 3.77, 95% CI: 1.16-12.20, P < 0.001; I2: 99.9%, p < 0.001). Although there was significant heterogeneity, in sensitivity analysis, based on alternative levels of I2 = 25%, we found no significant change in the pooled result (OR = 10.70, 95% CI: 10.19-11.22, P < 0.001). Conclusions: In conclusion, our research found that mass media campaigns may boost the usage of helmets among cyclists, particularly among those under the age of 18 and in campaigns without enforcement activities. Therefore, we suggest that these campaigns focus on children and adolescents. It is also recommended to use this type of campaign that can change the behavior of cyclists without coercion and activities.