Economic Burden of Veno-occlusive Disease in Patients With B-cell Acute Lymphoblastic Leukemia in the United States.

PURPOSE: The goal of this study was to evaluate the incidence, inpatient mortality, and economic burden of hepatic veno-occlusive disease (VOD) in adults with B-cell acute lymphoblastic leukemia (ALL) in the United States.

METHODS: Using MarketScan Commercial Claims and Encounters Database and Medicare Supplemental and Coordination of Benefits Database, data for patients with B-cell ALL from April 1, 2009, to October 31, 2016, were extracted by using diagnosis codes. VOD was identified based on clinical criteria and expert opinions. Patients with VOD were followed up from diagnosis of VOD until the earliest occurrence of inpatient death, end of continuous enrollment, end of study period, or for a maximum of 100days. The incidence of VOD and VOD-associated inpatient mortality were calculated. VOD-related health care costs based on paid adjudicated claims were calculated.

FINDINGS: Of the 2571 adults with B-cell ALL, the overall incidence of VOD was low at 3.4% (88 of 2571). Of these patients with VOD, 52% (46 of 88) experienced multiorgan failure and were identified as having severe VOD. VOD was only identified in patients having undergone hematopoietic stem cell transplantation (5.4% [88 of 1624]). The inpatient mortality rate of those with any VOD over the 100-day postindex period was 26.1%, and the inpatient mortality was even higher for patients with severe VOD (37.0%). Total mean (SD) medical costs per patient during the 100 days' post-VOD diagnosis were $55,975 ($160,335); mean (SD) costs per patient were ∼4-fold higher for severe ($86,953 [$206,906]) versus nonsevere ($22,047 [$72,847]) VOD.

IMPLICATIONS: Clinical criteria were used to identify VOD events and thus VOD might be underdiagnosed. The mortality of VOD also might be underestimated because only inpatient deaths are captured in the data. The incidence and mortality of VOD could also be underestimated because we focused on adult patients who might receive reduced-intensity treatment. The economic burden of VOD may be underestimated because the Healthcare Common Procedure Coding System code specific for defibrotide was not available, and thus the cost for defibrotide might not be included. Finally, as the study population consisted of patients with commercial or Medicare supplemental insurance, results may not be generalizable to all patients with VOD in the United States. Although VOD occurred infrequently in adults with B-cell ALL, it was associated with high inpatient mortality and substantial costs. Patients with severe VOD were associated with highest mortality and highest costs. Given the clinical and economic burden associated with VOD, it is important that patients at high risk for VOD be identified and treated to minimize this risk.