The Epworth Sleepiness Scale (ESS) describes the likelihood of falling asleep in 8 specific situations. Pathological sleepiness (TS) of patients with obstructive sleep apnea (OSA) is most often diagnosed with an ESS score≥11 (TS-ESS). In an epidemiological study on the prevalence of sleep apnea syndrome (OSAS), only three questions with yes-no answers were used for the characterization of pathological daytime sleepiness (TS-Young): Due to the different construction of the ESS and the Young's questionnaire, we asked whether with the combination of the two questionnaires a larger number of patients with OSA and TS compared to the ESS can be identified. In addition, we examined the sleepiness questionnaires (FB) using objective vigilance in defined groups of OSA patients.
Using PSG 328 OSA patients with an AHI≥5 were identified. Vigilance was examined using the computer program CARDA.
With both FB the same percentage of patients with AHI>5 with pathological sleepiness was found (48 %). By combining both FB (TS-comb), the number of patients increased from 158 (48.2 %) to 195 (59.5 %) significantly. The combination showed a significantly higher percentage with additional 37 (11.3 %) patients in comparison to the TS-ESS alone. Combining both FB, an increase of TS resulted in patients with below-average number of errors in the vigilance test (n=192) from 23.2 % to 31.4 % of these cases (p<0.001).
As a single test both questionnaires can be used to detect daytime sleepiness with equal incidence. Combining both questionnaires a higher percentage of daytime sleepiness can be found in comparison to the ESS-questionnaire alone especially in patients without disturbance of vigilance.