The reliability of the Epworth Sleepiness Score in a sleep clinic population

Abstract

Despite the Epworth Sleepiness Score being widely used, there are limited studies of its reliability in clinical practice. The aim of this study was to assess the reliability of the Epworth Sleepiness Score in a clinical population. The study included patients referred to Middlemore Hospital sleep service between October and November 2014, aged over 17 years, with at least two Epworth Sleepiness Score measurements at up to three different points on the diagnostic pathway: on General Practitioner referral (GP Epworth Sleepiness Score); at overnight oximetry assessment (Oximetry Epworth Sleepiness Score); and at a specialist clinic (Specialist Epworth Sleepiness Score). No treatment was administered between scores. One-hundred and thirty-three patients were included in the study. There was a median of 91 days from GP Epworth Sleepiness Score to Oximetry Epworth Sleepiness Score, and 11 days from Oximetry Epworth Sleepiness Score to Specialist Epworth Sleepiness Score. There was poor test-retest reliability between GP Epworth Sleepiness Score and Specialist Epworth Sleepiness Score; 72.4% and 17.8% of patients had an absolute difference of more than 2 and 8 Epworth Sleepiness Score points, respectively. A Bland-Altman plot of mean Epworth Sleepiness Score versus the difference between GP Epworth Sleepiness Score and Specialist Epworth Sleepiness Score demonstrated a wide scatter of data and 95% confidence interval for the difference in Epworth Sleepiness Score for an individual patient of -14 to +10. There was similar variability between GP Epworth Sleepiness Score and Oximetry Epworth Sleepiness Score. The reliability of the Epworth Sleepiness Score is unproven in clinical settings. This study shows poor test-retest reliability of Epworth Sleepiness Score, particularly between primary and secondary care, arguing against the use of Epworth Sleepiness Score for clinical decision-making or prioritisation of services without first assessing the reliability of the Epworth Sleepiness Score in the relevant clinical population.

Risk factors of excessive daytime sleepiness in a prospective population‐based cohort

“…Another limit is that several epidemiological studies conducted in clinical settings showed poor test−retest reliability of the ESS (Campbell, Neill, & Scott, 2018;Nguyen et al, 2006;Taylor, Zeng, & O'Dochartaigh, 2019). However, these studies had some weaknesses as the investigators had no control or knowledge on how the ESS were taken, and the study populations included individuals of different ethnicities with potential comprehension difficulties due to poor English language (Campbell et al, 2018;Taylor et al, 2019).…”

Short-Term Continuous Positive Air Pressure Treatment: Effects on Quality of Life and Sleep in Patients with Obstructive Sleep Apnea

“…As was also noted in our study, the perception of sleepiness when scoring ESS does not correlate with AHI. The retrospective analysis of patients with sleeping disorders by Lee et al also compared the variability of ESS scores at two time points [ 20 ]. They proposed that the ESS should not be used in clinical practice for assessing individual changes or prioritizing patients for diagnostic sleep disorder procedures.…”

Test–retest reliability of the Epworth Sleepiness Scale in clinical trial settings

“…Other methods, such as a naïve correlation analysis, are not sensitive to systematic differences in repeated measures. The present analysis evaluated data from prospective clinical trials, whereas most other studies retrospectively analysed data from chart reviews in clinical practice (Campbell et al, 2018;Lee et al, 2020;Nguyen et al, 2006;Taylor et al, 2019;Walker et al, 2020).…”

“…The test-retest reliability of the ESS has primarily been investigated in healthy, community-based samples (Ahmed et al, 2014;Johns, 1992;Knutson et al, 2006). A few studies (Campbell et al, 2018;Lee et al, 2020;Nguyen et al, 2006;Rozgonyi et al, 2021;Taylor et al, 2019;Walker et al, 2020) pants with EDS associated with narcolepsy or OSA, ESS scores were included as a primary or co-primary outcome measure (Malhotra et al, 2020;Schweitzer et al, 2019;Thorpy et al, 2019). The large sample sizes and structured nature of these studies provided an opportunity to assess the test-retest reliability of the ESS in a clinical sample in a clinical trial setting.…”