Consequences and costs of noncompliance with iron chelation therapy in patients with transfusion-dependent thalassemia: a literature review

BACKGROUND: Patients with thalassemia major require iron chelation therapy (ICT) to prevent complications from transfusional iron overload. Deferoxamine is effective, but requires administration as a slow continuous subcutaneous or intravenous infusion five to seven times per week. Deferiprone is a three-times-daily oral iron chelator, but has limited availability in the United States. Deferasirox is a once-daily oral iron chelator that was approved in the United States in 2005 for patients older than 2 years of age with transfusional iron overload. STUDY DESIGN AND METHODS: Published evidence on rates of compliance with ICT and the association between compliance, and the incidence and costs of complications of iron overload, in patients with thalassemia major was reviewed. RESULTS: A total of 18 studies were identified reporting data on compliance with ICT, including 7 that examined deferoxamine only, 6 that examined deferiprone only, and 5 that compared deferoxamine and deferiprone; no studies reporting compliance with deferasirox were identified. In studies of deferoxamine only, estimated mean compliance ranged from 59 to 78 percent. Studies of deferiprone generally reported better compliance, ranging from 79 to 98 percent. Results of comparative studies of deferoxamine and deferiprone suggest that compliance may be better with oral therapy. Numerous studies demonstrate that that poor compliance with ICT results in increased risk of cardiac disease and endocrinopathies, as well as lower survival. Although data on the costs of noncompliance are limited, a recent model-based study estimated the lifetime costs of inadequate compliance with deferoxamine to be $33,142. CONCLUSIONS: Inadequate compliance with ICT in thalassemia major is common and results in substantial morbidity and mortality, as well as increased costs.