The short-form health psychological capital questionnaire: psychometric validation and measurement invariance across Thailand and the United States

Health Psychological Capital (PsyCap) reflects individuals’ positive psychological resources, including hope, efficacy, resilience, and optimism, for managing health-related challenges. Although PsyCap is widely studied and applied, few validated non-English instruments are available to measure this construct. This study aimed to adapt and validate the short-form Health Psychological Capital Questionnaire (H-PCQ-12) for Thai-language use and to assess its cross-cultural measurement properties. Two studies involving three separately recruited samples were conducted using online surveys of adults aged 18–40 years. Study 1 included participants from Thailand ( N = 323) and the United States ( N = 295). Factor structure and reliability were examined in both samples, measurement invariance was tested across countries, and relations with external measures were examined in the Thai sample. Study 2 involved a separately recruited Thai sample ( N = 214) to replicate the factor-structure and reliability findings and selected validity evidence. Confirmatory factor analyses tested a second-order factor model, multigroup models evaluated measurement invariance, and Pearson correlations evaluated validity evidence based on relations with other PsyCap measures and theoretically related or distinct constructs. Across the three samples, the hypothesized second-order model demonstrated generally acceptable to excellent fit, and the H-PCQ-12 total score showed good to excellent internal consistency. Positive associations with other PsyCap measures provided convergent validity evidence, positive associations with quality of life and health behaviors provided evidence based on relations with health-related variables, and weaker correlations with sense of humor provided discriminant validity evidence. Measurement invariance analyses supported metric, but not scalar, invariance across the Thai and U.S. samples. The H-PCQ-12 scores demonstrated adequate reliability, and the findings provided validity evidence supporting their interpretation among Thai adults.