The road to danger: The comparative risks of driving while sleepy

Objectives/Hypothesis: A large sector of the population of the United State s has sleep deprivation directly leading to excessive daytime sleepiness. T he prevalence of excessive daytime sleepiness in this population ranges fro m 0.3% to 13.3%, The consequences of even 1 to 2 hours of sleep loss nightl y may result in decrements in daytime functions resulting in human error, a ccidents, and catastrophic events. The magnitude of risks in the workplace or on the highways resulting from sleepiness is not fully understood or app reciated by the general population. Hence, to more clearly emphasize the ma gnitude of these risks, we question whether mild sleep deprivation may have the same effect as alcohol on reaction times and driving performance. Stud y Design: Nonrandomized prospective cohort investigation, Methods: Sixteen healthy matched adult subjects (50% women) were stratified into two groups, sleep deprived and alcohol challenged, The sleep deprived group was furthe r subdivided into acute tone night without sleep) and chronic (2 h less sle ep nightly for 7 d) sleep deprivation, Each group underwent baseline reacti on time testing and then drove on a closed course set up to test performanc e. Seven days later, the group repeated this sequence after either sleep de privation or alcohol intake. Results: There were no significant between-gro up differences (sleep deprivation or alcohol challenged) in the changes bef ore and after intervention for all 11 reaction time test metrics. Moreover, with few exceptions, the magnitude of change was nearly identical in the t wo groups, despite a mean blood alcohol concentration of 0.089 g/dL in the alcohol-challenged group. On-track driving performances were similar (P =.7 24) when change scores (hits and errors) between groups were compared (base line minus final driving trial). Conclusion: This comparative model suggest s that the potential risks of driving while sleepy are at least as dangerou s as the risks of driving illegally under the influence of alcohol.