Development and validation of a motivation scale for health behavior change in patients with coronary heart disease: a cross-sectional study

Background Motivation is a critical psychological determinant of health behavior change in patients with coronary heart disease (CHD). Despite its theoretical and clinical importance, well-validated psychometric instruments specifically designed to assess motivation intensity in this population remain limited. This study aimed to develop and validate a motivation scale for health behavior change in patients with CHD. Methods A cross-sectional study was conducted in a tertiary hospital in China between April 2019 and December 2022 using a two-phase scale development design. The conceptual framework was based on the Contemplation-Action-Maintenance model. An initial item pool was generated through a literature review, existing instruments, and expert input, followed by Delphi consultation and patient-based pretesting in 76 patients with CHD. Item selection was performed combining Classical Test Theory and Item Response Theory in 749 patients. Psychometric properties were evaluated in an independent sample of 347 patients, including 35 who completed the scale twice. Reliability and validity were assessed using internal consistency, test–retest reliability, content validity, criterion validity, concurrent validity, and confirmatory factor analysis. Results The final scale comprised 12 items across three dimensions, explaining 86.04% of the total variance. The scale demonstrated good internal consistency (Cronbach’s α = 0.906) and test–retest reliability (ICC = 0.981, 95% CI [0.962, 0.990]). Criterion validity was supported by correlations with the General Motivation Subscale and Visual Analog Scale ( r = 0.469–0.751), while concurrent validity was supported by correlations with the Self-Efficacy Scale and Outcome Expectation Scale ( r = 0.505–0.595). Confirmatory factor analysis indicated an acceptable model fit. Conclusions The Motivation Scale for Health Behavior Change is a brief instrument that demonstrated acceptable reliability and validity in assessing motivation in patients with CHD. It may serve as a useful tool for assessing motivation and informing tailored behavior change interventions.