Propensity score matched assessment of treatment patterns and cost of erythropoiesis stimulating agent treatment in patients with cancer receiving myelosuppressive chemotherapy

Abstract

Objective:

To examine epoetin alfa (EPO) and darbepoetin alfa (DARB) treatment patterns and erythropoiesis stimulating agent (ESA) costs in patients with cancer receiving chemotherapy (CRC), and to compare the results observed in the pre-matched total study population (TSP) with a propensity score matched population (PSMP).

Methods:

A medical claims analysis was conducted from 1 January 2004 through 31 July 2009 using the HealthCore Integrated Research Database. Patients were at least 18 years old, newly initiated on EPO or DARB, received ≥ 2 ESA doses, and had ≥ 1 claim for cancer and chemotherapy proximate to ESA treatment. Patients were matched using propensity scores. January 2010 Wholesale Acquisition Cost was used to calculate drug cost. Mean cumulative ESA dose and drug costs were evaluated in the TSP and PSMP.

Results:

4921 EPO and 9173 DARB patients with CRC were identified. In the TSP, mean cumulative ESA doses were EPO: 398,770 units and DARB: 1508 mcg, with similar treatment durations for each. Mean cumulative drug costs were EPO: $6041 and DARB: $7861 (30% higher for DARB). The cumulative dose ratio (EPO units: DARB mcg) was 264:1. The PSMP analysis identified 4831 ESA treated CRC patients in each group. Mean drug costs were EPO: $6055 and DARB: $7863 (30% higher for DARB). The observed dose ratio (EPO units: DARB mcg) was 265:1.

Conclusion:

In both analyses, the costs of DARB were higher, even after accounting for baseline differences in the PSMP. Similar trends in dose ratios were also observed in both groups.