Sleep disorders, sleepiness, and near-miss accidents among long-distance highway drivers in the summertime.

OBJECTIVE: We aimed to investigate sleepiness, sleep hygiene, sleep disorders, and driving risk among highway drivers. METHODS: We collected data using cross-sectional surveys, including the Epworth Sleepiness Scale (ESS) questionnaire, Basic Nordic Sleep Questionnaire (BNSQ), and a travel questionnaire; we also obtained sleep data from the past 24 h and information on usual sleep schedules. Police officers invited automobile drivers to participate. RESULTS: There were 3051 drivers (mean age, 46±13 y; 75% men) who completed the survey (80% participation rate). Eighty-seven (2.9%) drivers reported near-miss sleepy accidents (NMSA) during the trip; 8.5% of NMSA occurred during the past year and 2.3% reported sleepiness-related accidents occurring in the past year. Mean driving time was 181±109 min and mean sleep duration in the past 24 h was 480±104 min; mean sleep duration during workweeks was 468±74 min. Significant risk factors for NMSA during the trip were NMSA in the past year, nonrestorative sleep and snoring in the past 3 months, and sleepiness during the interview. Neither sleep time in the past 24 h nor acute sleep debt (sleep time difference between workweeks and the past 24 h) correlated with the occurrence of near misses. CONCLUSIONS: Unlike previous studies, acute sleep loss no longer explains sleepiness at the wheel. Sleep-related breathing disorders or nonrestorative sleep help to explain NMSA more adequately than acute sleep loss.