The development of pictorial tools for obstructive sleep apnoea syndrome

Abstract

Introduction: Obstructive sleep apnoea syndrome (OSAS) is common but remains underdiagnosed and is linked with several disease states and increased risk of mortality. The key symptom, excessive daytime sleepiness, is commonly measured with the Epworth Sleepiness Scale which is not always easily completed by patients. The aim of this thesis is to develop pictorial material for assessing sleepiness and risk of OSAS.

Methods: Health literacy was measured in a sample sleep population and the Epworth Sleepiness Scale was investigated for ease of use. Images were developed to translate the Epworth into pictures and the response to pictures of ‘driving while sleepy’ was investigated in detail. A new tool, the pictorial Sleepiness and Sleep Apnoea Scale, was devised by adding four sleepiness images from the pictorial Epworth to four new images representing ‘risk of OSAS’. Evaluations were made in two populations of the tool’s potential in predicting those at risk of OSAS.

Results: Poor or impaired health literacy was found in 16% of patients attending the sleep clinic. Evaluation of the Epworth Sleepiness Scale found that a third of new patients made quantifiable errors. A preference for the pictorial Epworth Sleepiness Scale was reported by 55% of users and a kappa statistic indicated good agreement between the pictorial and traditional Epworth Sleepiness Scale. Drivers were more inclined to record feeling sleepy if the image in Q8 depicted the sleepy person in the car as a passenger. In a sleep clinic population the pictorial Sleepiness and Sleep Apnoea Scale was slightly better at predicting disease than the Epworth. In a cardiac rehabilitation clinic use of the witnessed apnoea image from the pictorial Sleepiness and Sleep Apnoea Scale, along with the Epworth Sleepiness Scale, helped to identify symptoms suggestive of sleep apnoea in a third of those screened. When investigated with a sleep study, the prevalence of sleep–disordered breathing in this patient group was 14.8%.

Conclusion: Pictorial tools for patients with potential obstructive sleep apnoea syndrome have clinical value and can help bridge the gap between poor or impaired health literacy and the material we use to assess sleepiness and likelihood of obstructive sleep apnoea syndrome.