Psychometric evaluation of the Chinese version of Sleep Health Index in pregnant women

Abstract

Objective: The aim of this study was to investigate the psychometric properties of the Chinese version of the Sleep Health Index (SHI-C) among pregnant women.

Design: Cross-sectional design.

Setting: Outpatient clinic of three hospitals in China.

Participants: Pregnant women (N = 264) aged between 18 and 45 years were recruited via convenience sampling.

Methods: The Pittsburgh Sleep Quality Index (PSQI), Epworth Sleepiness Scale (ESS) and Insomnia Severity Index (ISI) were used to measure sleep quality, daytime sleepiness, and insomnia, respectively. The Fatigue Assessment Scale (FAS) and the Edinburgh Postnatal Depression Scale (EPDS) were used to measure fatigue and depression, respectively. Structural validity was assessed via confirmatory factor analysis (CFA). Concurrent and convergent validity were assessed using bivariate correlation analyses. Known-group validity was assessed by comparing the SHI-C score between different groups. Cronbach's α was calculated for reliability.

Findings: The average sample age was 30.6 years old and their average score of SHI-C was 86.4 (SD 8.2). Based on PSQI, ISI, and ESS, 43.6%, 32.2%, and 26.9% had poor sleep quality, insomnia, and excessive daytime sleepiness, respectively. The SHI-C total and sleep quality sub-index scores had moderate to strong correlations with both PSQI (r=-0.542, p<0.01; r=-0.648, p<0.01) and ISI (r=-0.692, p<0.01; r=-0.752, p<0.01). The SHI-C total and sleep quality sub-index scores were significantly associated with ESS, FAS, and EPDS (r=-0.171 to -0.276; p<0.01). The SHI-C total score was higher in the second trimester and among those who were working, never drank coffee, or took a nap every day. The Cronbach's α of the SHI-C total and the sleep quality sub-index were 0.723 and 0.806, respectively. The Cronbach's α of sleep duration and disordered sleep sub-indices were 0.594 and 0.545, respectively.

Key conclusions: Overall, the SHI-C has good validity and acceptable reliability among the pregnant population in China. It can be a useful tool for the assessment of sleep health. More research is warranted to refine the sleep duration and disordered sleep sub-indices.

Implications for practice: The use of SHI-C would facilitate the assessment of sleep health among pregnant women, which could contribute to the promotion of perinatal care.

Keywords: Pregnancy; Psychometric properties; Sleep health; Sleep quality.