[A questionnaire to capture the functional effects of daytime drowsiness on quality of life in case of obstructive sleep apnea syndrome. Functional Outcomes of Sleep Questionnaire (FOSQ)].

The Functional Outcome of Sleep Questionnaire (FOSQ) is a questionnaire for capturing the function-specific quality of life (impairment due to daytime drowsiness). It is subdivided into five subscales/sections, each comprising four degrees of severity. So far, no standard values for healthy persons without sleep disorders exist in the German-speaking countries. The aim of our study was therefore first of all to establish standard values for healthy subjects as well as to verify the three quality criteria required for testing procedures (objectivity, reliability, validity). Finally, a comparison between health subjects and OSAS patients was carried out. The study included 210 health subjects and 150 OSAS patients. Regarding standardisation of the FOSQ, the following standard values for healthy persons without sleep disorders were determined for the five subscales: activity 21.4 +/- 2.9; vigilance 20.5 +/- 4.3; intimacy 22.3 +/- 3.9; social QoL 22.6 +/- 3.3; general capability 22.3 +/- 2.7. Age and weight (BMI) influences could be excluded. Concerning verification of the three quality criteria, good values could be established for objectivity, reliability and validity. As a result, significant differences between health subjects and OSAS patients were found. In the five quality of life areas captured (activity 15.8 +/- 4.9; vigilance 14.6 +/- 6.4; intimacy 17.3 +/- 6.5; social QoL 18.9 +/- 5.5; general capability 17.9 +/- 5.2), the patients achieved values distinctly inferior to those of the health probands. In summary, for the German-speaking area, due to its test design, this questionnaire represents a simple procedure for capturing the function-related reduction in quality of life for all age groups both in the clinical field and in case of particular questions relating to expert opinions.