Sleep Fragmentation and Risk of Automobile Accidents in Patients with Obstructive Sleep Apnea—Sleep Fragmentation and Automobile Accidents in OSA

Abstract

Objectives: Automobile accidents related to obstructive sleep apnea (OSA) represent an important public health concern. Frequent arousal response during sleep is responsible for the symptoms of daytime sleepiness and an increased risk of automobile accidents in patients with OSA. We therefore investigated the potential relationships between the intensity of arousal and occurrence of automobile accidents in OSA. Methods: We determined the incidence of automobile accidents in the past 5 years among 51 men with OSA (age, 58.5 ± 10.4 years) using a questionnaire. Daytime sleepiness was rated with the Epworth Sleepiness Scale (ESS). We calculated an automobile accident score, with two points per automobile accident causing damage and one point per near miss. Standard polysomnography was performed for all patients, and arousals were classified as electroencephalographic (EEG) arousal of an abrupt shift in EEG frequency alone and Movement arousal, which was defined as EEG arousal with increased electromyographic activity persisting for ≥3 s. The number of EEG or Movement arousals per hour (arousal index) was determined. Results: The Movement arousal index was significantly greater in the 27 patients who experienced at least one automobile accident causing damage than in the resting 24 patients who had no history of automobile accidents. Multiple regression analysis including age, body mass index, and sleep parameters revealed that the Movement arousal index was the most significant factor of risk for automobile accidents (β = 0.563, P = 0.017) as well as the ESS score (β = 0.417, P = 0.022). Conclusion: Movement arousal during sleep contributes to daytime sleepiness and the resulting frequent involvement of OSA patients in automobile accidents.