Association of presence and severity of Obstructive sleep apnea syndrome with accident risk in city bus drivers

Objective: To determine the relationship between frequency of traffic accidents and presence and severity of the disease in bus drivers who are at risk of having obstructive sleep apnea syndrome (OSAS). Method: In the present study, polysomnography (PSG) was applied on 162 city bus drivers directed to the sleep laboratory from a total of 1450 drivers after being determined as risky with regard to OSAS symptoms according to the questionnaire results. Their demographic characteristics, health status and accidents were compiled. Statistical analyses were made for those diagnosed with OSAS according to the PSG result and those with a traffic accident after which comparisons were made. Results: Obstructive sleep apnea syndrome was detected in 127 out of the 162 drivers determined to be risky with regard to OSAS based on the Berlin questionnaire result. While 35% of the drivers were normal according to the polysomnography (PSG) results in the study, 39 (24.1%) were determined as light OSAS, 35 (21.6%) as moderate OSAS and 53 (32.7%) as severe OSAS. While 105 (64.8%) of the cases had no accident, 37 (22.8%) were almost involved in an accident due to sleepiness and 20 (12.3%) were actually involved in an accident. A statistically significant relationship was determined between accident rates and OSAS severity (p:0.009; p<0.05). Conclusion: It was concluded that presence and increased severity of OSAS is an important risk factor for being almost or directly involved in an accident among city bus drivers, even though they were not driving for long distances.