Many health researchers have looked at whether helmet laws result in lower injury rates for bicyclists and most have found that they work. Still, that conclusion is open to criticism because many of these are not well-designed studies, according to investigator Anneliese Spinks, a research fellow in the Griffith University School of Medicine in Queensland, Australia.

“We searched to find the highest-quality evidence and it shows that with bicycle helmet legislation, head injuries decreased. By relying only on the highest-quality evidence, we hope to reduce some of the controversy over the issue,” says Spinks, co-author of a new review of studies.

Some regions, including those in Australia, have established universal bike helmet laws, but legislation limited to children is more typical. The five studies included in the new review evaluated children-only bike-helmet laws.

The review appears in the current issue of The Cochrane Library, a publication of The Cochrane Collaboration, an international organization that evaluates research in all aspects of healthcare. Systematic reviews draw evidence-based conclusions about medical practice after considering both the content and quality of existing trials on a topic.

Spinks’ team looked for studies that included a comparison group to better gauge changes in an area where legislation was enacted versus an area where bike helmets were not required.

Three of the five studies were fielded in the United States, two in Canada. One of the largest studies examined hospital records of bike-related injuries in California over 10 years to assess that state’s child helmet law. The authors conclude that traumatic brain injury in youth cyclists dropped by more than 18 percent after the bike-helmet law was established.

A Canadian study of more than 9,700 bicycle-related hospital admissions compared injury rates in children in provinces throughout the country. Provinces that enacted helmet interventions saw childhood head injuries fall by 45 percent. There was a 27 percent decrease in provinces with no interventions in place.

Three studies also found that helmet laws, or helmet law enforcement, lead to significantly greater bike helmet use. The increases ranged from 45 percent to 84 percent.

Spinks says most scientists believe that bike helmets protect children and that legislation is effective in reducing injury rates. However, she believes bike-helmet laws will continue to be a hot debate topic because solid research remains scarce about some of the biggest objections.

Skeptics worry that the legislation will have unintended, adverse consequences. One big concern is that some people will give up cycling to avoid wearing a helmet, and lose out on cycling’s health benefits. But Spinks says, “There hasn’t been a well-designed study that looked at what effects helmet legislation has on bicycle riding.”

The argument also comes with some unlikely assumptions, says pediatrician Brent Hagel, a physician researcher with the Alberta Children’s Hospital in Canada.

“If you are going to make that kind of assertion, then you are going to have to assume that people are going to stop cycling and they are going to start watching TV and not do anything else, which in my opinion is fairly unlikely. They may take up in-line skating or they may do some other activity that is good for cardiovascular health,” Hagel says.

There is little evidence to support the theory, but other debates revolve around the notion that helmet legislation prompts cyclists to ride in riskier ways or bike under less-safe conditions.

Spinks’ review did not turn up good evidence to support or discount any adverse effects of bike helmet legislation. It is likely, therefore, that policy makers who propose bike helmet legislation will continue to face considerable uncertainty.

“It’s going to be tough for them. I’d encourage them to work with researchers. We need more evaluative studies and we’re looking for more evidence to really answer this question definitively,” Spinks says.

Source: Health Behavior News Service