Objectives: The self-efficacy measure for sleep apnea (SEMSA) questionnaire was shown to be an effective tool to assess adherence-related cognitions on continuous positive airway pressure (CPAP) therapy in obstructive sleep apnea (OSA) subjects. SEMSA helps to solicit fundamental information for formulating strategies to promote CPAP adherence for better treatment outcomes. The objective of our study was to perform a linguistic and psychometric evaluation of a Chinese version of the SEMSA (SEMSA-C).
Methods: Data were obtained from 100 subjects in a randomized controlled trial (RCT) on CPAP education. Subjects were newly diagnosed of OSA and naïve to CPAP therapy.
Results: A 26-item SEMSA-C was obtained by a rigorous linguistic validation process. Internal consistency was high with Cronbach α>0.88. One-week test-retest intraclass correlation coefficient (ICC) ranged from 0.70 to 0.82. Principal component factor analysis identified three of the same hypothesized factors (perceived risks, outcome expectancies, and treatment self-efficacy) as in the original version. CPAP adherence was associated with outcome expectancies and treatment self-efficacy at 3-month assessment. Further, SEMSA-C demonstrated an improvement in self-efficacy after CPAP use.
Conclusions: SEMSA-C shows similar psychometric properties as the original English version. It is a reliable and responsive instrument to measure perceived risks, outcome expectancies, and treatment self-efficacy in Chinese subjects with OSA.
Trial registration: ClinicalTrials.gov NCT01173406.
Keywords: Continuous positive airway pressure; Linguistic; Obstructive sleep apnea; Psychometrics; Self-efficacy; Validation.
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