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.