Healthcare utilization and cost of care in elderly breast cancer patients enrolled in SWOG clinical trials.

IMPORTANCE: Patients with cancer are at risk for unplanned hospitalizations during treatment which can increase the cost of care. OBJECTIVES: To determine demographic and clinical factors associated with healthcare utilization and costs among clinical trial participants. DESIGN, SETTING, AND PATIENTS: We conducted a retrospective analysis among breast cancer patients over the age of 65 treated on SWOG clinical trials from 1999 to 2011 with trial data linked to Medicare claims. MAIN OUTCOMES AND MEASURES: The outcomes were healthcare utilization (emergency room visits (ER), hospitalizations) and costs from Medicare Claims. Demographic, clinical, and prognostic factors were captured from clinical trial records. We identified cardiovascular comorbidities/risk factors (CVD-RFs) of diabetes, hypertension, hypercholesterolemia, and coronary artery disease (CAD) from Medicare claims. Multivariable logistic and linear regression were used to assess the association between CVD-RFs and outcomes. RESULTS: Among the 708 patients included in the analysis, 160 (22.6%) experienced 234 separate hospitalizations, and 193 (27.3%) experienced 311 separate ER visits. Black race was associated with an increase in hospitalizations (OR [95% CI], 2.52 [1.10-5.79], p = 0.03), but not emergency room visits compared to white race. Diabetes, hypertension, hypercholesterolemia, and CAD were all independently associated with increased risk of both hospitalizations and ER visit. Hypertension had the strongest association, with more than a threefold risk of hospitalization for those with hypertension compared to those without (OR [95% CI], 3.16 [1.85-5.40], p /= 3 RFs, the risk of hospitalization was nearly 3 times greater compared to 0 or 1 CVD-RFs (OR [95% CI], 2.74 [1.71-4.38], p /= 2 significant CVD-RFs ($35,353 vs. $28,899, 22.3% increase, p = 0.005) had statistically significantly higher total healthcare costs. CONCLUSIONS: Among participants treated on clinical trials, black race and presence of multiple cardiovascular comorbidities was associated with a substantial increase in ER visits, hospitalizations and healthcare costs. Efforts to reduce unplanned hospitalizations should focus on this high-risk group.