The impact of aging on driving performance in patients with untreated obstructive sleep apnea.

Objective: To determine the influence of age on sleepiness-related driving performance in individuals with obstructive sleep apnea (OSA).

Design: Extended wakefulness protocol comparing simulated driving performance in younger and older individuals with OSA.

Participants: Fifty-two individuals with OSA (15 female) were median split into younger (≤55 years, n = 26) and older (>55 years, n = 26) groups.

Measurements: Participants underwent polysomnography to derive sleep parameters and confirm OSA diagnosis. One-to-2 weeks following polysomnography, participants completed a 60-minute driving simulation 4 hours prior to their habitual bedtime. Participants remained awake to 3 hours post habitual bedtime before repeating the task.

Results: Median age was 44.5 years (25th, 75th centiles = 37.0, 48.0) for the younger group and 64.5 years (60.0, 70.0) for the older group. When comparing the performance change between baseline and extended wakefulness, the younger patients had greater deterioration on all driving simulator parameters (crashes, standard deviation of lateral position, speed deviation and braking reaction time, all p < .05), compared to the older group. Linear regression found a 10-year age increase was associated with an a ∼30%-41% reduction in crash occurrence when accounting for covariates (p = .023). Age also predicted standard deviation of lateral position deviation, but not when sleep efficiency and self-reported sleepiness were included as covariates.

Conclusion: Older participants with OSA were less vulnerable than younger participants to sleepiness-related driving simulator impairment when assessed at night-time following extended wakefulness. Future work should assess naturalistic on-road driving to determine if this extends to a variety of challenging driving scenarios.