Assessment of proportional hazard rate of cardiac disease in major Beta Thalassemia in Shiraz 2005-2006

Background and Thalassemia is the most common hereditary anemia in Iran and around the world that needs regular transfusion. Transfusion may lead iron overload in the body. Absence or irregular therapy chelation (Desferal usage) in these patients leads to various complications that the most important of them are cardiac diseases. The purpose of this study was to evaluate the hazard rate of cardiac disease and related factors using COX model. This descriptive analytical study carried out on eight-hundred and six thalassemic (406 males and 400 females) patients referring to Cooley’s ward of dastgheib hospital of Shiraz were studied using a structured questionnaire through enumeration method. Age of occurrence, demographic information, age of onset and type of transfusion, and age of onset and method of chelation therapy were specified. Specialist physicians diagnosed the complications. Data were analyzed using descriptive and analytical (Proportional hazard rate and its confidence interval using COX model) statistics. In our subjects ages ranging were 1-43 years and mean±SD was 15.34±6.82 years. The prevalence of cardiac diseases was 15.9% that it was estimate among female and male 17.8% and 14%, respectively (p>0.05). The mean of age of onset of cardiac diseases was 16.93±5.43 years that it was estimate among female and male 16.41±4.8 and 17.58±6 years, respectively (p>0.05). There was a significant association between proportional hazard rate of cardiac diseases and age of chelation therapy onset and educational level of parents (p<0.05). Proportional hazard rate of this complication was not related to blood group, sex, chelating methods and type of transfused blood (p>0.05). Early onset of blood transfusion with late onset of chelating increases the occurrence probability and early onset of cardiac disease complications. For prevention of these complications, it is recommended that onset of blood transfusion be according to onset of chelating. Educational level of parents and education to parents and patients very important. Progression of complications is prevented by regular survey and early diagnosis of complications and leads to high efficacy of patients.