Bone marrow transplantation versus periodic prophylactic blood transfusion in sickle cell patients at high risk of ischemic stroke: a decision analysis

Abstract

Measurement of cerebral blood velocity (CBV) by transcranial Doppler has been used to identify patients with sickle cell disease (SCD) who are at high risk of ischemic stroke. This study examines outcomes of bone marrow transplantation (BMT) and periodic blood transfusion (PBT) as a basis for making treatment recommendations for patients who have elevated CBV and no other indications for BMT. Decision analysis was used to compare the number of quality-adjusted life years (QALYs) experienced by a population of patients with SCD at high risk for stroke who were treated with PBT or BMT. Markov models were constructed to represent the clinical course of patients with SCD who were treated with PBT or BMT. Medical literature and expert opinion provided risks of stroke and death for different disease states, estimates of transition probabilities from one clinical state to another, and quality of life. An intention-to-treat analysis and an analysis of treatment received were both performed on hypothetical cohorts of 100 000 patients. Patients with SCD who were managed with a strategy of intending to provide BMT could expect 16.0 QALYs, compared with 15.7 QALYs for a strategy of intending to provide PBT; however, the variation around these estimates was large. In the treatment received analysis, patients compliant with PBT therapy and iron chelation could expect the best outcomes (19.2 QALYs). From a policy perspective, neither BMT nor PBT can be considered the "best" treatment for children with SCD who have abnormal CBV. Abnormal CBV should not be the only criterion for selecting patients with sickle cell for BMT.