Factors Associated With Unplanned Hospitalizations Among Patients With Nonmetastatic Colorectal Cancers Intended for Treatment in the Ambulatory Setting

Abstract

Background: Chemotherapy administration and supportive management for solid tumors is intended to take place in the ambulatory setting, but little is known about why some patients experience treatment-related adverse events so severe as to require acute inpatient care.

Objective: The aim of the study was to identify predictors of initial and repeated unplanned hospitalizations and potential financial impact among Medicare patients with early-stage (Stages I-III) colorectal cancer receiving outpatient chemotherapy.

Methods: Advanced statistical modeling was used to analyze a cohort of patients (N = 1,485) from the Surveillance, Epidemiology, and End Results (SEER)-Medicare database diagnosed from 2003 to 2007 with colorectal cancer as their first primary malignancy. Patients were of ages 66 and older at diagnosis, had uninterrupted Medicare Parts A and B coverage with no health maintenance organization component, and received chemotherapy at least one time.

Results: Female gender, younger age, multiple comorbidities, rural geography, higher high school completion rates, and lower median income per census tract were significant predictors of the likelihood of initial unplanned hospitalizations. Non-White race, receipt of radiation therapy, rural geography, and higher weighted comorbidity scores were factors associated with the number of hospitalizations experienced. The total Medicare charges calculated for these admissions was $38,976,171, with the median charge per admission at $20,412.

Discussion: Demographic and clinical factors that form the foundation of work toward development of a risk factor profile for unplanned hospitalization were identified. Further work is needed to incorporate additional clinical data to create a clinically applicable model.

FIGURE 1

Formation of the colorectal cohort. SEER-Medicare files initially contain the entire population of all patients with the requested tumor type diagnosed in contributing SEER sites across the nation. Eligibility and other study criteria quickly reduce the remaining population available for analysis.

FIGURE 2

Logic model illustrating flow of cases into Hospitalized or Nonhospitalized groups within the colorectal cohort.

FIGURE 3

Key dates defining the study observation periods.