1Lane Fox Respiratory Unit/Sleep Disorders Centre, Guy’s & St Thomas’ NHS Foundation Trust, London, UK;2King’s College London, Faculty of Life Sciences and Medicine, London, UK
Background: Excessive daytime sleepiness (EDS) is a contributing factor to road traffic accidents. It is usually assessed using self-administered questionnaires. These assessments are important information when discussing with the Driver and Vehicle Licensing Agency (DVLA) about fitness-to-drive. We hypothesised that patients may be confounded in their assessments after being informed about these potential implications.
Methods: This was a prospective single centre study. Patients attending clinics for sleep-disordered breathing were asked to fill in the Epworth Sleepiness Scale (ESS) and Stanford Sleepiness Scale (SSS). Following their consultation, patients were informed about EDS in the context of driving and that the DVLA might request information based on their self-assessed sleepiness. They were then asked to complete the questionnaires a 2nd time. Parameters recorded included age, gender, BMI, driving licence holder and collar size.
Results: One hundred and twenty-two subjects were studied [age 59.4 (15.15) years; 72 males; BMI 32.1 (8.3) kg/m2, driving licence held for 25.2 (20.6) years (n=94); collar size 42.7 (5.0) cm]. Seven patients (5.7%) changed their scores from “sleepy” to “non-sleepy”, and four patients (3.3%) from “non-sleepy” to “sleepy”. There was no difference in the ESS [8 (8) vs. 8 (8) points; P=0.289] or the SSS [2 (2.25) vs. 2 (2) points; P=0.320] between the two occasions.
Conclusions: Providing patients with information about the risk of driving in the context of sleepiness does not significantly change how they score using self-administered questionnaires, despite increased intra-occasional variability in about 1/10 of the patients.