Validity and reliability of the sleep health index among community-dwelling older adults

Sleep health represents a positive and multidimensional framework that extends beyond the absence of sleep disturbances or insufficient sleep duration. Despite its clinical relevance, empirical research on sleep health in older adults remains limited. The Sleep Health Index (SHI) was developed to comprehensively evaluate sleep health. This study aimed to validate the Chinese version of the SHI among community-dwelling older adults.

This is a cross-sectional design. Older adults aged 60 years and above were recruited (n = 274), and a subset (n = 60) was invited to complete the test-retest survey after a two-month interval. The SHI-C, Pittsburgh Sleep Quality Index (PSQI), Insomnia Severity Index (ISI), Epworth Sleepiness Scale (ESS), 15-Item Geriatric Depression Scale (GDS-15), comorbidity burden (aCCI), and handgrip strength (HGS) were administered to assess sleep health and related health indicators. The SHI-C was evaluated for structural, convergent, concurrent, known-group validity, internal consistency, and test-retest reliability.

Exploratory factor analysis supported a three-factor structure, which was subsequently confirmed by confirmatory factor analysis (i.e., sleep quality, sleep duration, and disordered sleep), consistent with the original validation study. Parallel analysis further confirmed the three-factor solution. Measurement invariance testing across gender supported full metric and scalar invariance. The SHI-C demonstrated concurrent validity through strong negative correlations with both the PSQI (r = -0.624) and ISI (r = -0.696). It also showed weak but significant associations with the ESS (r = -0.328) and the GDS-15 (r = -0.329). Known-group validity was supported as participants with chronic diseases, insomnia, or depression had significantly lower SHI-C scores (p < 0.001). Furthermore, the total score of SHI-C exhibited a significant negative correlation with the aCCI (r = -0.302) and a significant positive correlation with HGS (r = 0.171), supporting its association with key objective health indicators. The SHI-C showed acceptable internal consistency (Cronbach's α = 0.775) and test-retest reliability (intraclass correlation coefficient = 0.784).

The SHI-C is a reliable and valid measurement for assessing sleep health in community-dwelling older adults. These findings suggest its potential utility for the sleep health assessment among this population, thereby contributing to the geriatric care enhancement.