Abstract
PURPOSE: This nationwide Danish cohort study compared overall survival (OS) between non-Western immigrant patients and Danish-born patients with lymphoma in Denmark. Furthermore, differences in clinical and socioeconomic variables were compared, and mediators of OS differences were explored to explain possible outcome differences. PATIENTS AND METHODS: The study included a total of 540 non-Western patients and 16,294 Danish-born patients diagnosed with lymphoma in the period 2000-2020. Inverse probability weighting and mediation analysis using a natural effects Cox model were used to investigate the causal relationship between immigration status and OS. RESULTS: Indirect effects mediated through differences in performance status and income indicated a trend towards inferior OS for non-Western immigrant patients with HRs of 1.06 (0.99-1.14) and 1.06 (0.99-1.14). However, no total causal effect of immigration status on OS was observed overall (HR: 0.94 [0.79-1.12]) and within subtype-specific analyses, except for classical Hodgkin lymphoma. CONCLUSION: No significant differences in OS between non-Western immigrant patients and Danish-born patients were discovered.