Objective: Obstructive sleep apnea (OSA) is a common disorder in many ethnic populations. Patients with OSA have impaired health-related quality of life (HRQOL). No sleep apnea-specific HRQOL measure has been validated in Chinese patients.
Study design and setting: A cross-sectional sample of 106 Chinese OSA patients and a longitudinal sample of 51 patients in Hong Kong completed a Chinese (Cantonese) version of SAQLI for assessment of its acceptability, scaling assumptions, reliability, validity, and responsiveness.
Results: The instrument was understood and seen as relevant by 97% of subjects. Internal consistency, test-retest reliability, item-scale convergent validity and discriminatory validity, and construct validity were good to excellent. Construct validity was confirmed by significant correlations with SF-36 subscale scores. However, factor analysis showed that only items of daily functioning and symptom domains all loaded on the hypothesized scales. Longitudinal data showed that SAQLI was more responsive than SF-36 to changes after treatment.
Conclusion: Hence, this version of SAQLI was an acceptable, psychometrically valid, and responsive HRQOL measure for evaluating impact of illness and treatment effectiveness in Chinese OSA patients.