Dr. Dan’s Food for Thought

Meet Dr. Dan Fishbein. An epidemiologist formerly with the CDC, he now is active in the South Coast cycling community. His love of data and familiarity with research publications mean he is a great filter for important data related to bike safety, infrastructure, and riding trends. Below are three articles about helmet use – food for thought in your protected head! He has been kind enough to provide a brief summary for each article.

Protective value of bicycle helmets re-affirmed (Hoye, A. Bicycle helmets – To wear or not to wear? A meta-analyses of the effects of bicycle helmets on injuries https://www.ncbi.nlm.nih.gov/pubmed/29677686)A meta-analysis has been conducted of the effects of bicycle helmets on serious head injury and other injuries among crash involved cyclists. 179 effect estimates from 55 studies from 1989-2017 are included in the meta-analysisThe use of bicycle helmets was found to reduce head injury by 48%, serious head injury by 60%, traumatic brain injury by 53%, face injury by 23%, and the total number of killed or seriously injured cyclists by 34%. Bicycle helmets were not found to have any statistically significant effect on cervical spine injury. The results do not indicate that bicycle helmet effects are different between adult cyclists and children. It is likely that bicycle helmets have larger effects among drunk cyclists than among sober cyclists, and larger effects in single bicycle crashes than in collisions with motor vehicles.

Helmet laws do not decrease ridership (Hoye, A. Recommend or mandate? A systematic review and meta-analysis of the effects of mandatory bicycle helmet legislation https://www.ncbi.nlm.nih.gov/pubmed/30173006). Mandatory bicycle helmet legislation can be expected to reduce head injury among crash involved cyclists. Some adverse effects may occur, but will not necessarily be large or long-lasting. People who may be deterred from cycling, are among those with the highest injury risk and the smallest health effects from cycling. If the overall goal is to improve safety for all cyclists and to increase cycling, mandatory bicycle helmet legislation should be supplemented by other measures, especially improved bicycle infrastructure.

Wearing a helmet does not lead riskier cycling (Risk compensation? The relationship between helmet use and cycling speed under naturalistic conditions. https://www.ncbi.nlm.nih.gov/pubmed/30553419):  One argument against recommending or mandating bicycle helmets is that cyclists might ride faster – and therefore increase the risk of injury – when they wear a helmet. This study we equipped both bicycles and cyclists with data acquisition systems to record speed and trip distance.  The authors found that trip length, bicycle type, and cyclist age increased risk, but helmets did not.