Driving simulator performance remains impaired in patients with severe OSA after CPAP treatment

Abstract

Study Objectives: To assess the effectiveness of CPAP treat¬ment in improving 90-minute driving simulator performance in severe OSA patients compared to age/gender matched con¬trols. Design: Driving simulator performance was assessed at base-line and 3 months later, with OSA patients treated with CPAP during the interval. Setting: University Teaching Hospital. Participants: Patients with severe OSA (n = 11) and control subjects without OSA (n = 9). Interventions: CPAP Measurements and Results: Simulator driving parameters of steering deviation, braking reaction time and crashes were measured at baseline and ~3 months follow-up. At baseline, OSA subjects demonstrated significantly greater steering de¬viation compared to controls (mean [95% CI], OSA group, 49.9 cm [43.7 to 56.0 cm] vs control group, 34.9 cm [28.1 to 41.7 cm], p = 0.003). Following ~3 months of CPAP treatment (mean ± SD 6.0 ± 1.4 h/night), steering deviation in OSA subjects improved by an average of 3.1 cm (CI, 1.4 to 4.9), p < 0.001, while no significant steering changes were observed in the control group. Despite the improvement, steering deviation in the OSA group remained significantly higher than in controls (OSA group, 46.7 cm [CI, 40.6 to 52.8 cm] vs control group, 36.1 cm [CI, 29.3 to 42.9 cm], p = 0.025). Conclusions: While driving simulator performance improved after ~3 months of CPAP treatment with high adherence in patients with severe OSA, performance remained impaired compared to control subjects. These results add to the grow¬ing body of evidence that some neurobehavioral deficits in patients with severe OSA are not fully reversed by treatment. Further studies are needed to assess causes of residual driv¬ing simulator impairment and to determine whether this is as¬sociated with persistent elevated real-life accident risk.