Caffeine May Boost Driver Safety
The researchers interviewed all the drivers, gathering information about various health and lifestyle issues, including caffeine consumption over the past month. The study was published online in BMJ.
After adjusting for age, driver experience, distance driven, hours of sleep, naps, night driving and other factors, they found that drivers who consumed caffeine were 63 percent less likely to be involved in a crash.
Results Forty three percent of drivers reported consuming substances containing caffeine, such as tea, coffee, caffeine tablets, or energy drinks for the express purpose of staying awake. Only 3% reported using illegal stimulants such as amphetamine ("speed"); 3,4 methylenedioxymethamphetamine (ecstasy); and cocaine. After adjustment for potential confounders, drivers who consumed caffeinated substances for this purpose had a 63% reduced likelihood of crashing (odds ratio 0.37, 95% confidence interval 0.27 to 0.50) compared with drivers who did not take caffeinated substances.
According to the lead author, Lisa N. Sharwood, a research fellow at the George Institute for Global Health in Sydney, Australia, this does not mean that caffeinated drinks are the answer for road safety.
Censored data alert:
By excluding those who were involved in the most serious crashes, one misses the possibility that caffeine use might not be associated positively and might, in fact, be associated negatively, or that, while being associated positively in terms of the number of crashes, is associated negatively with the seriousness of crashes.From the report: "Potential case participants were excluded if there was a fatality associated with the crash, the driver of the commercial vehicle was seriously injured (defined as being admitted to hospital for two weeks or more or losing consciousness as a consequence of the crash),...."
Use of caffeinated substances and risk of crashes in long distance drivers of commercial vehicles: case-control study
BMJ 2013; 346 doi: http://dx.doi.org/10.1136/bmj.f1140 (Published 19 March 2013)
Cite this as: BMJ 2013;346:f1140