[Value of retrospective assessment of the Epworth Sleepiness Scale after long-term CPAP therapy in obstructive sleep apnea disorder]].

Background: Daytime-sleepiness is the main symptom of the obstructive sleep apnoea syndrome. Standarized questionnaires (e.g. the Epworth sleepiness scale = ESS) have become useful diagnostic tools. In this study we investigated wether there is a difference between the estimation of initial "pre-treatment" daytime sleepiness (by ESS) compared to the retrospective ESS score after implementation of CPAP therapy.

Methods: We included 46 patients (RDI 39/h +/- 20.2, CPAP pressure 8 cm/H2O +/- 1.7, daily use of 5.8 h +/- 1.8, RDI with CPAP 7.6/h +/- 5.3). We examined the ESS score before CPAP-therapy (ESS-base) in comparison to the retrospective estimation of the initial conditions after one year of CPAP-therapy (ESS-retro).

Results: There was no statistical significant difference between ESS base (11.7 +/- 4.6) and ESS-retro (12.7 +/- 5.2). ESS decreased to 5.4 +/- 3.7 by CPAP-therapy (p < 0.01).

Conclusions: From a chronological point of view ESS is a consistent parameter of daytime sleepiness. Hence, the retrospective estimation of pre-CPAP ESS can be considered as a useful diagnostic tool.