PRS14 THE ECONOMIC BURDEN OF BRONCHIOLITIS OBLITERANS SYNDROME (BOS) IN ALLOGENIC HEMATOPOIETIC STEM CELL TRANSPLANT (ALLOHSCT) PATIENTS WITH MEDICARE COVERAGE

Bronchiolitis Obliterans Syndrome (BOS) is a rapidly progressive obstructive airway disease characterized by T-cell mediated inflammation and fibrosis which leads to respiratory failure and death with a 5 year survival of 13% in allogenic HSCT (alloHSCT). This study characterized healthcare resource use and costs in alloHSCT Medicare patients who developed BOS. The data source for this retrospective longitudinal study was the Medicare Limited Dataset; study timeframe was 01/01/2010-12/31/2017. Study participants were age-eligible (>=65yrs) and disability-eligible (<65yrs) fee-for-service beneficiaries with an index BOS diagnosis (ICD-9: 491.8, 491.9, 515, 516.34, 561.8; ICD-10: J41.8, J42, J84.09, J84.89, and J84.115), and prior alloHSCT. Outcome measures were patient characteristics, costs paid by Medicare, and healthcare resource utilization in patients who survived at least 1 year. Analyses were repeated for patients who survived 2 and 3 years. Among 2,022 patients, 41% were female; mean age was 62.1yrs (SD:12.5); 42.6% (N=861) were <65yrs. Mean per-patient costs in the first post-BOS diagnosis year were $47,737 (SD:66,300). Among those who survived, costs declined to $22,782 (SD:48,920; N=1,436) in year 2 and $12,519 (SD:35,195; N=939) in year 3. Inpatient admissions averaged $27,842 (SD:51,770) per-patient in the first year post-diagnosis, decreasing to $11,239 (SD:34,761) in year 2 and $6,499 (SD:23,856) in year 3. Mean per-patient hospitalization rates in the first post-diagnosis year were 1.6 (SD: 2.0), declining to 0.7 (SD:1.6) in year 2 and 0.4 (SD:1.2) in year 3. Mean length of hospital stay 21.2 (SD:29.1), 17.8 (SD:31.3) and 16.4 (SD:19.8) days in years 1,2, and 3, respectively. More than 2 in 5 Medicare alloHSCT patients who develop BOS are age <65 disability-eligible patients. Inpatient costs underlie approximately half of the economic burden of BOS over time. The yearly decline in costs reflects decreasing hospitalization rates and may reflect survival of healthier patients.