Acute Myeloid Leukemia in the Elderly: Longitudinal Outcomes and Hospital Charges in Chemotherapy and Non-Chemotherapy Patients.

Background: Patients with acute myeloid leukemia (AML) have an estimated median age of 65 to 70 years (J Clin Oncol1999;17:3569–76). The overall incidence of the disease increases with increasing age. The five-year survival rate for AML is 2% among elderly patients (Arch Intern Med2002;162:1597–1603). Treatment includes cytotoxic chemotherapy [e.g., the “7+3” regimen consisting of cytarabine and daunorubicin or idarubicin (Leukemia1996;10:389–95)], which can be associated with serious morbidity and is often not tolerated by older patients. Over 80% of Medicare payments for treating AML are attributable to hospitalization costs (Arch Intern Med2002;162:1597–1603). Methods: A longitudinal cohort design was employed using an inpatient database containing information on over three million individuals from 28 hospitals in the US. The study population included patients aged 60 years and older with initial AML diagnosis between January 2000 and June 2003. Patients were followed across multiple admissions, from first inpatient encounter through last discharge from hospital. Descriptive statistics (demographics and hospital characteristics), comorbidities, chemotherapies, outcomes, resource utilization, and charges were examined; multivariate linear regressions were performed. Results: 275 patients were identified and included in these analyses. The mean age upon first AML admission was 74.3 years (SD=8.1) and 46.6% of patients were female. On first admission, the mean length of stay (LOS) was 14.7 days (SD=14.3), 37.8% of patients received chemotherapy, and one quarter of all patients (25.3%) died. Patients incurred a mean total charge of $70,305 on first admission, while the median was $17,640; patients on chemotherapy had mean and median total charges of $113,118 and $74,689, respectively, versus $43,999 and $9,784, respectively, for non-chemotherapy patients. Chemotherapy patients also had a higher mean LOS than non-chemotherapy patients (23.0 vs. 6.7 days, respectively). 44.4% of patients had a least one re-admission with a mean of 36.4 days (SD=62.1) between the first and second admissions. For re-admissions, the mean LOS and charges were 8.9 days (SD=15.3) and $38,785 (median $13,936), respectively. Across all admissions, 41.4% of patients received chemotherapy and 40.7% of patients died in-hospital. Over the entire study period, patients incurred a mean total charge of $115,471 with a median charge of $49,168. In multivariate analyses, after adjustment for covariates, chemotherapy was found to be a significant predictor (p<0.0001) of admission charges, LOS, and total days of stay. Conclusion: Elderly patients with AML incurred substantial charges and inpatient mortality. The highest charges and the majority of deaths occurred during first admission. Current chemotherapy regimens in these patients were associated with substantially increased charges.