Development and Validation of the HLS-Q12-OA Health Literacy Instrument for Older Adults: A Multidimensional Rasch...

Health literacy (HL) is pivotal to healthy aging, yet existing instruments often show suboptimal psychometric performance in older populations. This study aimed to develop and validate a concise HL instrument tailored to older adults and evaluate its psychometric properties.

A cross-sectional survey of 957 community-dwelling Chinese adults (≥ 60 years) used the Chinese HLS-EU-Q47. Unidimensional and between-item multidimensional Rasch analyses removed items with poor fit, differential item functioning (DIF), or local dependence. The retained 12-item HLS-Q12-OA was assessed via exploratory factor analysis (EFA) for its factor structure and confirmatory factor analysis (CFA) for model fit. Reliability was evaluated using Cronbach's α, McDonald's ω, and person separation reliability (PSR). Findings were compared with the original HLS-EU-Q12 and international adaptations.

Rasch analysis revealed substantial item misfit and DIF in the original HLS-EU-Q47. The HLS-Q12-OA showed no floor/ceiling effects (rates 0.10%-6.79%). EFA suggested three factors with high inter-factor correlations; CFA supported a unidimensional structure with excellent fit (CFI = 0.991, GFI = 0.983, AGFI = 0.974, RMSEA = 0.032) and all factor loadings > 0.5. Reliability was satisfactory (Cronbach's α = 0.891, McDonald's ω = 0.894, PSR = 0.892). The HLS-Q12-OA outperformed the original HLS-EU-Q12 in the same sample; its Cronbach's α was slightly lower than Japanese/Chinese adult versions but higher than Jordanian/Turkish versions, with the best construct validity and no age-related DIF.

The HLS-Q12-OA is the first unidimensional short-form HL scale developed specifically for older adults. It overcomes key psychometric limitations of the original HLS-EU-Q47 and offers a reliable, valid, and practical tool for HL screening in geriatric and community settings.