Combined Chelation Therapy and Survival of Beta-Thalassemia Major: A Retrospective Cohort Study

Background: There recently are multiple different iron-chelation regimens among thalassemia patients in Iran. The aim of our study was evaluated the efficacy of combined chelation therapy on survival time of the beta-thalassemia major patients. Methods: A retrospective cohort study was performed on 667 beta-thalassemia major patients in Shiraz, Iran. Using a predetermined checklist data were collected from their medical records. For analysis, patients were divided into two groups (exposure variable); one drug (single-agent therapy) and two or more drugs (combination therapy). Dependent variable is survival time following combination therapy. We used Kaplan-Meier curves and Cox proportional hazards model to identify the effect of combined therapy against mortality of the patients. Results: Both crude (HR=0.30, 95%CI: 0.19, 0.43) and adjusted (HR=0.52, 95% CI: 0.31, 0.86) hazard ratios showed that combination therapy was significantly associated with decreased risk of mortality. The 10-year, 20-year and 40-year survival rates for patients with combination therapy were 99%, 93% and 78%, respectively. However, the 10-year, 20-year and 40-year survival rates for patients receiving single agent therapy were 98%, 74% and 47%, respectively. Conclusion: The findings of this study showed that the combination therapy is associated with lower risk of mortality. Future prospective studies are needed in future to examine this association to achieve the maximum accuracy of the results.