[Comparative evaluation of two health-related quality of life questionnaires in patients with sleep apnea].

Symptoms and complications of the obstructive sleep apnea (SAS) lead to a significant impairment of the health-related quality of life (HRQOL) of the affected individuals. Most HRQOL questionnaires have been published in English. Formal process of evaluation has to precede the introduction of a new language version of a HRQOL questionnaire. We conducted a comparative evaluation of the Polish versions of two HRQOL questionnaires: The Calgary Sleep Apnea Quality of Life Questionnaire (SAQLI) and The Functional Outcomes of Sleep Questionnaire (FOSQ). We examined the reliability, validity, stability and responsiveness of both questionnaires. Cronbach's alpha coefficient amounted to 0.94 for both questionnaires, which confirmed their reliability. Scores of both questionnaires highly correlated with measures of daily sleepiness, general health and SF-36 questionnaire scores. Both SAQLI and FOSQ gave stable results, but SAQLI was found to be more sensitive than FOSQ. The Polish version of FOSQ was proved to be a useful tool in cross-sectional assessment of HRQOL in patients with SAS. Stability and responsiveness of the Polish version of SAQLI and normal distribution of its scores make this questionnaire a preferable instrument in repeated assessments of HRQOL in the same group of patients.