Introduction: Respiratory effort-related arousals (RERA) are secondary to subtle obstructions of the upper airway during sleep and can appear in the absence of a predominance of apneas and hypopneas, causing excessive daytime sleepiness. Analyzing the possible consequences of these new respiratory events is of increasing interest. Habitually sleepy drivers are at high risk of having traffic accidents related to sleep disorders (apneas, hypopneas and RERA).
Objective: The aim of this study was to determine whether excess RERA alone is an independent risk factor among sleepy drivers.
Method: We studied 40 habitually sleepy drivers and 23 age- and sex-matched controls selected from a sample of 4,002 automobile drivers. We surveyed sleep habits, daytime sleepiness and traffic accidents. Sleep studies of esophageal pressure were performed.
Results: The sleepy drivers with apneas (apnea/hypopnea index > 10) had a higher 5-year accident rate (0.33 0.50) than did control drivers (0.004 0.21; p < 0.05). However, a high RERA index, but not sleep apnea, was an independent risk factor among the habitually sleepy drivers. The adjusted odds ratio (OR) for a RERA index > or = 10 was 7.6 (confidence interval [CI], 1.2 to 48); for a RERA index > or = 15, the OR was 17 (CI 1.5 to 91).
Conclusions: The high risk of traffic accidents among sleepy drivers is mainly determined by the presence of RERA rather than the presence of apneas and hypopneas. These findings verify the importance of identifying RERA in routine sleep laboratory studies.