Professional identity formation, professionalism, leadership and resilience: a longitudinal assessment in medical students

Professional Identity Formation (PIF) is integral to medical education, underpinning how students internalize the values, attitudes, and behaviours expected of physicians. Despite growing interest in PIF, most existing studies rely on qualitative or cross-sectional designs, limiting evidence on how PIF can be assessed quantitatively and tracked longitudinally across medical training. This study aimed to examine whether PIF can be assessed quantitatively using the Professional Self-Identity Questionnaire (PSIQ), and how it relates to the development of professionalism, leadership, and resilience in two cohorts of medical students using a longitudinal design. Data were drawn from the Professional Identity Formation, Professionalism, Leadership, and Resilience (PILLAR) study, conducted between 2019 and 2024, a longitudinal assessment of medical students at RCSI University of Medicine and Health Sciences. A longitudinal completer sample of 146 students (95 Direct Entry undergraduate Medicine (DEM) students and 51 Graduate Entry Medicine (GEM) students) were followed from entry to final year. Repeated assessments were conducted over five years for DEM and four years for GEM, using 76 items from four well-established scales measuring PIF, professionalism, leadership, and resilience. A hierarchical mixed-effects model was applied to examine developmental changes. PIF (PSIQ-scores), reflecting the transition from student to qualified doctor, showed a significant and progressive increase across training stages up to the final year in both DEM (β = 2.61; 95% CI 2.33, 2.89, p < 0.001) and GEM (β = 2.39; 95% CI 2.00, 2.78, p < 0.001) programs. No consistent changes were seen for professionalism, leadership or resilience for either DEM or GEM. PSIQ scores demonstrated a significant upward trajectory across medical training, whereas professionalism, leadership, and resilience did not show comparable temporal change. These findings provide feasibility and consequential validity evidence for the PSIQ as a repeated longitudinal quantitative measure for monitoring professional identity development and supporting programmatic curriculum evaluation in medical education.