Abstract

Background and Aim

Obstructive Sleep Apnoea (OSA) is a recognised contributor to driving impairment, yet its real-world impact remains underappreciated in clinical practice. Traditional severity measures like the Apnoea-Hypopnoea Index (AHI) and subjective sleepiness scores often fail to capture functional risk. This study sought to determine the prevalence of sleep-related driving impairment in OSA using multiple targeted questions and exploring associations with demographic and clinical factors, aiming to build a comprehensive understanding of how OSA affects driving.

Methods

Retrospective analysis from patients with OSA who attended sleep clinic between May and September 2023. Inclusion criteria consisted of a confirmed OSA diagnosis, a completed sleep clinic questionnaire and being a driver. Patients completed four questions on driving impairment (near-misses, accidents, head-nodding, and needing breaks while driving due to fatigue) as part of a standard clinical symptom questionnaire. A positive response to any of the four question items was deemed indicative of driving being affected. Deprivation deciles were assessed using the Index of Multiple Deprivation (IMD), based on patients’ postcodes. Subjective daytime sleepiness was assessed using the Epworth Sleepiness Scale (ESS). The relationships between reported driving impairment and clinical variables were evaluated.

Results:

162 patients met the study inclusion criteria with cohort characteristics shown in Table 1. In total, 47 (29.0%) drivers reported at least one feature of impaired driving, and 38% of this group reported more than one feature. However, the nature of driving impairment was not consistent in the responses. 30 (18.5%) patients reported head-nodding, 26 (16.0%) needing to stop for breaks, 12 (7.4%) reported near-misses and 3 (1.9%) having experienced road traffic accidents. Notably, there was no association between driving impairment and OSA severity, but ESS was found to be significant (p<0.001).

Conclusion

Driving impairment is frequently self-reported among individuals with OSA, affecting 29% in this study population but with no relationship with disease severity. However, greater ESS can be used as a predictor of driving impairment. Our findings highlight the importance of screening for driving impairment in all patients and the need for multi-question tools to identify risks more comprehensively.