Transition shock trajectories and their reciprocal mediation with professional identity on nursing interns' retention: A longitudinal study with educational implications

BACKGROUND: Transition shock (TS) is a core stressor influencing nursing students' career choices. However, its dynamic trajectories during internship and influence on retention intentions remain underexplored. OBJECTIVES: To identify heterogeneous TS trajectories in nursing interns, examine associations of psychological capital, internship bullying, and organizational support with trajectory categories, and investigate the longitudinal reciprocal effects between TS and professional identity (PI) and their subsequent impact on retention intentions. DESIGN: A prospective longitudinal study with three time points. SETTINGS: University hospitals in Changsha, Hunan Province, China. PARTICIPANTS: A total of 826 nursing interns were recruited. METHODS: Data on TS, PI, and retention intentions were collected at internship weeks 4 (T1), 24 (T2), and 40 (T3) between October 2024 and December 2025. Growth mixture modeling identified TS trajectories, multinomial logistic regression analyzed influencing factors, and cross-lagged panel models examined longitudinal mediating relationships. RESULTS: Three distinct TS trajectories were identified: low-shock stable group (45.0%), high-to-low shock group (32.0%), and high-shock stable group (23.0%). Lower psychological capital (OR = 0.81, P < 0.001) and higher internship bullying (OR = 2.06, P < 0.001) were significantly associated with high-shock stable trajectory. A bidirectional mediating relationship emerged: TS at T1 (β = -0.031, Bootstrap 95% CI [-0.046, -0.017]) and T2 (β = -0.041, Bootstrap 95% CI [-0.057, -0.025]) indirectly reduced T3 retention intentions through their negative association with T2 PI; conversely, T2 PI indirectly diminished T3 retention intentions through its association with TS at T2 (β = -0.047, Bootstrap 95% CI [-0.067, -0.028]) and T3 (β = -0.041, Bootstrap 95% CI [-0.060, -0.023]). CONCLUSION: TS among nursing interns follows heterogeneous paths, with the high-shock stable group as priority for intervention. TS and PI form a mutually reinforcing longitudinal relationship negatively associated with retention intentions. Nursing educators across academic and clinical settings should collaborate to strengthen psychological capital, reduce internship bullying, and repair PI during mid-internship, thereby interrupting this detrimental relationship and reducing early workforce attrition.