Excess Mortality, Length of Stay, and Costs Associated with Serious Fungal Infections among Elderly Cancer Patients: Findings from Linked SEER-Medicare Data

To calculate the excess mortality, length of stay, and costs attributable to serious fungal infections in hospitalized elderly patients with selected cancers. This study involved a retrospective cohort analysis using linked data from the Surveillance, Epidemiology and End Results Program of the National Cancer Institute (SEER) and Medicare claims data. Study cohorts included patients aged 65 years and older who newly received a diagnosis of a selected cancer (acute myeloid leukemia [AML] or squamous cell carcinoma of the head and neck [SCCHN]) in a SEER registry between 1991 and 1996 and who had a subsequent diagnosis of a serious fungal infection during an inpatient hospitalization, and hospitalized controls without a fungal infection matched 1 : 1 by age, geographic region, receipt of recent chemotherapy, concomitant bacterial infection, timing of the index hospitalization, and cancer stage at diagnosis (for SCCHN patients only). Eighty AML patients and 52 SCCHN patients experienced a serious fungal infection involving hospitalization. Relative to matched controls, SCCHN patients with fungal infections had significantly higher all-cause mortality (40% vs. 14%, P = 0.002), while mortality rates did not differ between AML cohorts. Patients with fungal infections had significantly longer index hospitalizations regardless of cancer type (mean: 30 days vs. 19 days for AML patients; 20 days vs. 9 days for SCCHN patients), and correspondingly higher Medicare payments (mean ± SD: $34,268 ± $31,811 vs. $21,416 ± $22,449 among AML patients, P < 0.0001; $25,942 ± $29,122 vs. $10,131 ± $10,686 among SCCHN patients, P < 0.0001). Efforts to prevent these infections and/or initiate early treatment may yield both clinical and economic benefits.