DETERMINANTS OF SLEEPINESS IN AUTOMOBILE DRIVERS

Governmental agencies do not systematically investigate the presence o f daytime sleepiness as a determinant of driving accidents. We surveye d automobile drivers traveling on summer vacations and driving long di stances on a European highway. We evaluated their subjective daytime s leepiness while driving and any sleep deprivation just prior to depart ure. Five-hundred sixty-seven automobile drivers (mean age 37.7 +/- 11 years) were interviewed at a roadside rest-stop. Questions covered th e sleep/wake schedule during the year, sleep habits, and the presence of symptoms frequently associated with sleep-disordered breathing. Sle ep behavior just prior to departure was compared to the usual sleep sc hedule during the year. Fifty percent of the responders had a sleep re striction just prior to departure (mean -203 minutes) compared to usua l total sleep time during the year; 10% had no nocturnal sleep prior t o departure. Drivers younger than 30 years were significantly more acu tely sleep deprived than other drivers. Economic migrants (subjects wi th low economic status) also experienced significant acute sleep restr iction.