Material and Method: Thirty-eight healthy volunteers, 35 primary snorers (PS), and 108 patients with obstructive sleep apnea (OSA) diagnosed with polysomnography (PSG) were asked to fill questionnaires including Thai version of Short Form-36 (SF-36), and Epworth sleepiness scale (ESS). Thirty-two subjects with OSA who had been using CPAP adequately were asked to complete SF-36 twice, before and three months after treatment initiation.

Results: The role-physical and general health dimensions of SF-36 in OSA patients and PS were significantly lower than healthy volunteers (p<0.05). Other dimensions were not significantly different among groups of subjects. Nonetheless, the scores in all dimensions of SF-36 in OSA patients were lower than those of general population of Thailand, except for mental health. There were only weak but significant correlations between physical function, role-physical, general health, vitality, and role-emotional dimensions and ESS scores (r = 0.17-0.29). Most of PSG parameters, particularly apneahypopnea index, did not correlate with SF-36 scores except for a weak correlation between mean oxygen saturation and role-physical, mental health, and vitality dimensions. However, there was a significant improvement in all dimensions of SF-36 after three months of adequate CPAP therapy (p<0.01).

Conclusion: Thai patients with OSDB had poorer HRQOL compared to healthy subjects and general population at least in some dimensions, and an effective CPAP use can improve them. However, there was almost no relationship between HRQOL and PSG findings.

Keywords: Quality of life, Obstructive sleep disordered breathing, Sleep apnea, Thai