Purpose: The prevalence of under-diagnosis among individuals with obstructive sleep apnea (OSA) is alarming, and may be associated with perceptions regarding OSA. To facilitate future studies on OSA, this study validated the revised version of the Illness Perception Questionnaire (IPQ-R) for OSA in a general population.

Methods: A random anonymous population-based telephone survey interviewed 580 adults aged ≥ 50 years in Hong Kong, who self-reported not having been told by doctors as having OSA, from February 5 to March 19, 2021.

Results: The confirmatory factor analysis identified a modified 7-factor model (i.e., timeline chronic, consequence, personal control, treatment control, illness coherence, timeline cyclical, and emotional representation) that showed satisfactory model fit index and internal consistency. Nine items were removed from the original version because of low factor loadings. No floor and ceiling effects were observed. Convergent validity was supported by the positive associations between the consequence subscale with perceived negative outcomes of OSA and between the illness coherence subscale and perceived understanding of OSA symptoms. The participants tended to endorse the items of timeline chronic, treatment control, and illness coherence but not with those of emotional representations. The mean scores of the IPQ-R subscales differed by age and education level.

Conclusion: The modified IPQ-R of OSA showed acceptable psychometric properties. It is applicable to assessing illness perceptions of OSA in the Chinese general population aged ≥ 50 years not having received OSA diagnosis. The validated tool would support future studies and health practices related to OSA.