Obstructive sleep apnoea syndrome as a cause of road traffic accidents

Several studies have demonstrated that obstructive sleep apnoea syndrome (OSAS) patients have a higher rate of road traffic accidents. Our study aimed to analyse any differences in OSAS patients between those who reported having had road traffic accidents and/or near misses and those who did not.

We studied 163 patients with OSAS (apnoea- hypopnoea index (AHI)>10/h) diagnosed using nocturnal polysomnography (NPSG), all drivers, 18.4% of whom drove for a living. Patients were asked at their first clinical interview to self-report road traffic accidents and/or near misses over the past 3 years which had been caused by abnormal daytime drowsiness. This allowed patients to be divided into two groups, those who had had road traffic accidents and/or near misses and those who had not. Both were compared as to age, body mass index (BMI), Epworth Sleepiness Scale (ESS), daytime PaO2 and PaCO2, Functional Outcomes of Sleep Questionnaire (FOSQ) test and NPSG data. This latter was total sleep time (TTS), sleep efficiency, sleep stages, arousal index (ARI), AHI, minimal and average SaO2, % of time with SaO2 < 90% (T90), desaturation index (ODI), total duration of apnoea-hypopnoea (TDAH) (T test).

Group I (no road traffic accidents) No=89 patients; group II (road traffic accidents) No=74 patients. Age (years) was 57.6+/-11.8 vs. 54.7+/-10.9 (ns); male gender, 75% vs. 78.4%; ESS, 12.3+/-5.4 vs. 17.6+/-4.3 (p<0.001); BMI, (Kg/m2) 36.2+/-8.1 vs. 35.6+/-6.3 (ns); PaO2 (mmHg), 76.1+/-11.4 vs. 78.5+/-12.6 (ns); PaCO2 (mmHg), 42.6+/-5.1 vs. 42.2+/-4.7 (ns); FOSQ, 15.1+/-3.1 vs. 12.9+/-3.4 (p<0.001). NPSG data revealed differences only in AHI: 45.0+/-21.6 vs. 56.2+/-29.7 (p=0.01) and in TDAH (minutes), 98.5+/-63.7 vs. 133.3+/-83.2 (p=0,005).

In our experience patients who had road traffic accidents and/or near misses had a more severe OSAS, with higher AHI, excessive daytime sleepiness and lower quality of life.