Proceedings of The Physiological Society

Sleep Sleep and Circadian Rhythms (London, UK) (2018) Proc Physiol Soc 42, C12

Poster Communications

Can a Visual Analogue Scale (VAS) be used to measure sleepiness in patients diagnosed with Obstructive Sleep Apnoea (OSA)?

A. Dawidziuk2, Y. Alqurashi1, J. Moss1, M. Polkey1, M. J. Morrell1

1. National Heart and Lung Institute, Imperial College London, London, United Kingdom. 2. College of Medicine, Imperial College London, London, United Kingdom.


  • Figure 1. Bland-Altman plots of agreement between ESS and VAS results of healthy participants (n=32) and OSA patients (n=31) collected at visits 1 and 2.

Motivation: The Epworth Sleepiness Scale (ESS) is the most commonly used questionnaire for the assessment of sleepiness. However, it is variable between individuals, not applicable in all countries, and requires high level of literacy. Visual analogue scales have been validated in the assessment of chronic symptoms such as anxiety and pain. The aim of this study was to investigate the efficacy of a newly developed Visual Analogue Scale (VAS) for the measurement of sleepiness, compared to ESS, in patients with Obstructive Sleep Apnoea (OSA) and healthy participants. Methods: A prospective, observational study was carried out in patients with OSA and healthy participants. All of the participants completed 2 visits during which they filled in both ESS and VAS. Between visits 1 and 2 the patients diagnosed with OSA were treated with Continuous Positive Airway Pressure (CPAP). The agreement between the VAS and ESS results was assessed using Bland-Altman plots. Secondary outcomes were the ease of use (0-10 Likert scale) and the time taken in each measurements. Results: 32 patients diagnosed with OSA (age [Mean±SD] 55.80 ± 13.49 years) and 32 healthy participants (age: 36.74 ± 11.65 years) were recruited. Both ESS and VAS detected a reduction in sleepiness after CPAP treatment in patients with OSA (ESS: 11.16 ± 5.53 to 4.74 ± 5.01 a.u., p<0.001, VAS: 50.22 ± 30.08 to 21.90 ± 26.52 mm, p<0.001). There were no significant differences between visit 1 and visit 2 in healthy participants using both ESS and VAS (ESS: 3.91 ± 3.41 to 3.07 ± 3.27 a.u., p=0.31, VAS: 15.58 ± 21.21 to 9.12 ± 10.93 mm, P=0.138). The Bland-Altman agreement is shown in Figure 1. In patient with OSA, the time taken to complete the VAS (visit 1: 14.92 ± 13.76 seconds, Visit 2: 5.67 ± 3.39 seconds) was significantly less compared to ESS (visit 1: 38.75 ± 20.01 seconds, Visit 2: 31.33 ± 23.68, p=0.001). Conclusion: The findings of this study suggest that the new VAS is an effective measure of sleepiness in patients with OSA and healthy participants. The VAS is also able to detect changes in sleepiness in patients with OSA treated with CPAP.

Where applicable, experiments conform with Society ethical requirements