Does wearing helmets reduce motorcycle-related death? A global evaluation

Background: The high risk of injury and death of motorcycle riders is a major global health problem. This study aimed to evaluate the effect of helmet wearing on motorcycle riders' death rates on a global level. Methods: Data for motorcycle riders were collected from 70 countries. These data included motorcycle-related death rates per 100 000 population, helmet non-usage percentage, Gross National Income per capita (GNI), number of registered motorized 2-3 wheelers, the effectiveness of law enforcement in each country, and whether there was standards for helmets use or not. Correlations between studied variables were done using Pearson correlation. Multiple linear regression models were used to define factors affecting motorcycle-related death rates. Results: The correlation between motorcycle-related death rate and helmet non-usage, was almost significant (p = 0.056, r = 0.28). Helmet non-usage percentage was significantly correlated with GNI (p < 0.0001, r = -0.61) and effectiveness of the law (p < 0.0001, r = -0.73). A multiple linear regression model which was highly significant (adjusted R-squared = 0.3, F = 6.69, p < 0.001) has shown that helmet non-usage percentage (p = 0.003), motorcycle per person ratio (p = 0.01) and the presence of helmet standards (p = 0.05) were positively associated with motorcycle-related death rates. A simple linear regression model between helmet usage and road traffic death rate has shown that for each 10% increase in helmet usage, one life per 1 000 000 inhabitants can be saved per year. Conclusion: Helmet non-usage percentage was the most significant factor affecting motorcyclists' death rate. Wearing a motorcycle helmet reduces the risk of death from a motorcycle crash. Enforcement of motorcycle helmet laws should be effectively supported by motorcycle safety programs.