Trends in 5-, 10-, 20-, and 30-year survival rates of beta-thalassemia patients in Southern Iran, 1995-2016: A retrospective cohort study

Background: There is currently lack of knowledge about survival trend analysis of thalassemia patients. Therefore, the aim of the present study was to assess 5-, 10-, 20-, and 30-year survival of thalassemia patients over a 20-year time period. Methods: In this retrospective cohort study, we analysed the data of 982 beta-thalassemia patients in Iran. Birth cohort and traditional cohort analyses were used to obtain the 5-, 10-, 20-, and 30-year survival rates in various time intervals between 1995 and 2016. Results: Five and 10-year survival rates remained unchanged since 1995-2016. Overall, 20- and 30-year survival rates were lower in younger birth cohorts than older ones. A declining trend was found in 20-year survival rate from 1995 to 2000 for all and also for thalassemia major patients, but was stable from 2001 to 2016. In addition, there was a declining trend in 30-year survival rate from 1995 to 2008 for all and also for thalassemia major patients, but was an increased trend from 2009 to 2016. Conclusion: Over the past two decades and in recent birth cohorts, the 20- and 30-year survival rates has declined. In other words, declining survival trends in the birth cohorts may be associated with some different causes of mortality such as exposure to the toxic effects of iron over time and the occurrence of diseaserelated mortality.