Site of Care May Impact Breast Cancer Management and Economic Outcomes

San Diego—Patients with nonmetastatic HER2+ breast cancer who were administered trastuzumab in an outpatient hospital setting incurred higher total monthly healthcare costs compared with patients treated in an office clinic, according to information presented during a poster session. They also had a higher incidence of nontrastuzumab-related outpatient hospital and office clinic visits.

Trastuzumab-based therapies are recommended by National Comprehensive Cancer Network (NCCN) guidelines as adjuvant therapy for women with HER2+ breast cancer, ideally for 1 year. Patients may receive therapy in an office clinic or an outpatient hospital setting.

Results of a retrospective observational study to assess the proportion of patients receiving therapy in either an office clinic or an outpatient hospital setting were presented during a poster session at the AMCP meeting. The poster was titled Comparison of Healthcare Resource Utilization and Costs between Patients who Received Trastuzumab in an Outpatient Hospital versus Office Clinic Setting for the Treatment of Breast Cancer.

The researchers obtained data from the US-based Humana Database for the dates May 2007 through April 2012. Women with a confirmed diagnosis of breast cancer and at least 2 medical claims for a trastuzumab infusion at either an outpatient hospital or office clinic, and with full insurance coverage, were eligible for the study.

Based on the site of care at the index date (the date of the first prescription fill), a total of 730 patients were split into 2 cohorts: (1) 490 treated in an office clinic and (2) 240 treated in an outpatient hospital setting. Patients were similar in age and comorbidity profile.

Healthcare resource utilization included inpatient admissions, emergency department (ED) visits, outpatient hospital and office clinic visits, and other medical services. Healthcare costs consisted of all medical and pharmacy costs (inpatient admissions, ED costs). Trastuzumab-related visits and costs were classified as medical visits/costs.

After adjusting for confounding factors, results showed patients treated in an outpatient hospital setting had a lower incidence of trastuzumab-related visits (adjusted incidence rate ratio [IRR], 0.83; P<.001) and a higher incidence of nontrastuzumab-related visits (IRR, 1.10; P=.04).

The researchers also found total healthcare costs to be statistically significantly lower for patients in the office clinic compared with the outpatient setting by $1676 per month (P<.001). Nontrastuzumab-related total healthcare costs comprised about 60% of the total healthcare costs, which were found to be statistically significantly lower for patients treated in an office clinic ($6745 vs $5412, with an adjusted cost difference of $1437; P<.001).

Patients in the outpatient hospital cohort were also found to have an incremental medical cost of $1688 per month (P<.001). The researchers determined these differences to be due mainly to the combined office and outpatient costs that were higher in the outpatient hospital cohort ($10,404 vs $8659; adjusted cost difference of $1634; P<.001). Compared with patients treated in an outpatient setting, patients treated in the office clinic incurred lower nontrastuzumab-related office and outpatient costs ($5841 versus $4458 with an adjusted cost difference of $1405; P<.001).

There are common limitations that are inherent to retrospective observational studies that come with the use of claims data, as well as possible coding errors or data omissions (which are, however, unlikely to affect conclusions). Additionally, the severity of breast cancer varies among patients and therefore may affect outcomes as well as the choice of site of care.

This study was supported by Genentech, Inc.