Mortality Among Neutropenic Cancer Patients Within the United States: The Association With Hospital Volume

PURPOSE Neutropenia is a serious complication of chemotherapy in patients with solid tumors. The influence of hospital volume on outcomes in patients with neutropenia has been little investigated. We hypothesized that large-volume hospitals would have reduced mortality rates for neutropenic patients compared with small-volume institutions. METHODS We used the Nationwide Inpatient Sample database of the Healthcare Cost and Utilization Project, for the years 2007-2011. All adult inpatient episodes with a diagnosis of both neutropenia and solid-tumor malignancy were included. Hospital volume was defined as the number of neutropenic cancer episodes per institution per year. Mortality was defined as death during admission. A multilevel mixed-effects logistic regression model was applied. RESULTS Twenty thousand three hundred and ten hospitalizations were included in the study, from 1,869 different institutions. Median age was 62 years. The overall inpatient mortality was 2.3%, and was dependent on age (age 50-59 years—1.6% and age 80-89 years—5.3%). The median number of neutropenic inpatient episodes in each institution per year was 14 (range, 1-168). Mortality was 3.3%, 2.7%, 2.2%, 2.2%, and 1.2% for each quintile of hospital volume (from lowest to highest volume, P, .001). Likewise, the proportion discharged home was 85.7%, 90.3%, 91.5%, 92.7%, and 95.4% (P, .001). The association between hospital volume and mortality remained significant after adjustment for patient-level and hospital-level variables. DISCUSSION Patients with neutropenia hospitalized in large-volume institutions have a substantially lower mortality compared with those hospitalized at low-volume institutions. Further study is required to validate our findings or overcome potential biases, understand mechanism, and investigate how smaller institutions can improve outcomes.