title: Driving simulator performance remains impaired in patients with severe OSA after CPAP treatment.
abstract: OBJECTIVE
  To assess the effectiveness of CPAP treatment in improving 90-minute driving simulator performance in severe OSA patients compared to age/gender matched controls.
  
  
  METHODS
  Driving simulator performance was assessed at baseline and 3 months later, with OSA patients treated with CPAP during the interval.
  
  
  METHODS
  University Teaching Hospital.
  
  
  METHODS
  Patients with severe OSA (n = 11) and control subjects without OSA (n = 9).
  
  
  METHODS
  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 deviation 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 growing 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 driving simulator impairment and to determine whether this is associated with persistent elevated real-life accident risk.
  
  
  BACKGROUND
  Data presented in this manuscript was collected as part of a clinical trial "Experimental Investigations of Driving Impairment in Obstructive Sleep Apnoea" ACTRN12610000009011, http://www.anzctr.org.au/trial_view.aspx?ID=334979
authors.affiliation: Adelaide Institute for Sleep Health, Repatriation General Hospital, Adelaide, Australia. andrew.vakulin@health.sa.gov.au
authors.forename: Andrew
authors.initials: A
authors.lastname: Vakulin
authors.forename: Stuart D
authors.initials: SD
authors.lastname: Baulk
authors.forename: Peter G
authors.initials: PG
authors.lastname: Catcheside
authors.forename: Nick A
authors.initials: NA
authors.lastname: Antic
authors.forename: Cameron J
authors.initials: CJ
authors.lastname: van den Heuvel
authors.forename: Jillian
authors.initials: J
authors.lastname: Dorrian
authors.forename: R Doug
authors.initials: RD
authors.lastname: McEvoy
mesh_terms: D000063:Accidents, Traffic / Q000706:statistics & numerical data; D001334:Automobile Driving / Q000706:statistics & numerical data*; D045422:Continuous Positive Airway Pressure / Q000379:methods*; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D011597:Psychomotor Performance; D011930:Reaction Time; D020181:Sleep Apnea, Obstructive / Q000503:physiopathology* / Q000628:therapy*; D016896:Treatment Outcome