Abstract

Background: – The Self-Care Self-Efficacy Scale version 3.0 (SCSES-v3.0) measures self-efficacy in various chronic conditions. However, its psychometric properties in specific conditions and non-Western contexts are not well understood. Objective: – We evaluated the psychometric properties of the Thai version of the SCSES-v3.0 in patients with heart disease. Methods: – In this cross-sectional methodological study, we recruited patients with heart disease from 2 hospitals and 15 primary care settings. We evaluated structural validity using exploratory and confirmatory factor analysis, and hypothesis testing against the Self-Care of Chronic Illness Inventory version 4.c (SC-CII-v4.c). Reliability was assessed using McDonald’s ω, Cronbach α, intraclass correlation coefficients, and measurement errors were calculated for score precision. Results: – Of 300 patients, 287 were included in the analysis after excluding outliers. Exploratory factor analysis conducted with the first split-half subsample revealed a 2-factor structure: one factor represented self-efficacy in maintenance and monitoring behaviors (items 1–5), and the other represented self-efficacy in management behaviors (items 6–10). Confirmatory factor analysis conducted with the second split-half subsample and the overall sample confirmed the scale’s bidimensional model with high factor loadings. The dimensions and overall SCSES-v3.0 positively correlated with each scale and the overall SC-CII-v4.c. Reliability was excellent for internal consistency (range, 0.91–0.94) and test-retest reliability (range, 0.95–0.97). The measurement error results were satisfactory. Conclusions: – The SCSES-v3.0 demonstrated robust psychometric characteristics. Its validity and reliability make it a valuable instrument for clinical practice and research with the potential to enhance patient outcomes in heart disease management.