['The relationship between the severity of the apnea-hypopnea index (AHI) and the quality of life (QOL) in patients with obstructive sleep apnea (OSA) has been inconsistent in previous studies. This study aimed to identify the core factor associated with the QOL of suspected OSA patients and to compare the QOL of subjects with OSA and simple snoring (SS).', 'Two hundred eighty-five subjects who were clinically suspected to have OSA underwent nocturnal polysomnography (PSG) and completed self-report questionnaires including the World Health Organization Quality of Life Short Form (WHOQOL-BREF) and the Pittsburgh Sleep Quality Index (PSQI). The effects of the clinical and PSG variables on the QOL score were analyzed using multiple stepwise regression analyses, and the QOL of OSA and SS groups was compared.', 'In correlation analyses, the most significant factor that correlated with the QOL of the subjects was the PSQI total score (p\xa0<\xa00.001), while the AHI was not related to the WHOQOL-BREF total score. In multiple linear regression analysis, the PSQI total score was the most significant factor associated with the QOL of participants (p\xa0<\xa00.001). The mean score of the WHOQOL-BREF did not differ significantly between the OSA group and the SS group.'] Is the quality of life of suspected obstructive sleep apnea patients related to their subjective sleep quality rather than the apnea-hypopnea index?