Cross-cultural validation of the social empathy index: a psychometric study among Japanese medical students

BACKGROUND: Assessing and fostering social empathy among medical students is crucial for advancing health equity. While education on the social determinants of health (SDH) has become increasingly important in medical curricula, its impact has been evaluated mostly through qualitative approaches. Quantitative assessment tools that assess social empathy remain limited in medical education. The Social Empathy Index (SEI) is a self-report instrument designed to assess interpersonal and social empathy and may have relevance for medical education. OBJECTIVES: This study aimed to examine the psychometric properties of the Japanese version of the SEI (SEI-J) among medical students and explore its potential application in medical education in Japan. METHODS: A total of 414 medical students from three academic years at a private medical school in Tokyo completed the SEI-J and a self-developed sociodemographic questionnaire. Confirmatory factor analysis was conducted to examine structural validity based on the original SEI framework. Internal consistency was assessed using McDonald's omega coefficients. Known-groups validity was examined using one-way analysis of variance. RESULTS: Of the participants, 279 completed the survey (response rate 67.4%); 230 responses were included in the final analysis. Confirmatory factor analysis provided partial support for the original multidimensional structure of the SEI-J, and McDonald's omega coefficients indicated acceptable to high internal consistency across subscales. Higher SEI-J scores were associated with female gender, volunteering or study-abroad experience, interest in the arts or literature, people-oriented specialty preference, and greater self-rated understanding of SDH, consistent with prior research. CONCLUSIONS: The findings demonstrate that the SEI-J is a psychometrically valid and reliable tool for measuring social empathy. This study provides preliminary evidence supporting the applicability of the SEI in a Japanese medical education context, identifies factors associated with the development of social empathy, and offers an outcome measure that supports the evaluation and iterative improvement of SDH- and equity-oriented curricula.