Defining care provided for breast cancer based on medical record review or Medicare claims: information from the Centers for Disease Control and Prevention Patterns of Care Study

Abstract

Background

Description of care patterns is important as evidence-based guidelines increasingly dictate care. We explore the level of agreement between claims and record abstraction for guideline concordant multidisciplinary breast cancer care.

Methods

From the U.S. Centers for Disease Control and Prevention's National Program of Cancer Registries Patterns of Care study, in which medical record abstraction of breast cancer and treatment was accomplished, cases include breast cancer where Medicare claims were available. Components of care were breast-conserving surgery (BCS), mastectomy, node assessment, radiation (RT), and chemotherapy (CTX), including specific chemotherapeutic agents, and combinations. We compared Medicare claims with record abstraction, and measured concordance using the kappa statistic and sensitivity.

Results

The study sample consisted of 1762 women with stage 0 to 4 breast cancer. Level of agreement was excellent for surgery type (kappa = 0.84) and CTX (kappa = 0.89); agreement for RT therapy was slightly lower (kappa = 0.79). For standard multicomponent strategies, sensitivities and specificities were high; for example, 88.8%/93.5% for mastectomy plus nodes and 86.6%/95.4% for BCS plus nodes and RT. For selected, standard, multi-agent, adjuvant CTX regimens, sensitivities ranged from 66.3% to 68.8% (kappa 0.63–0.73).

Conclusions

Medicare claims, compared with chart abstraction, is a reliable method for determining patterns of multicomponent care for breast cancer.

Introduction

Treatment guidelines, taking into account tumor and patient characteristics, have been promulgated for various types of cancer [1]. Despite this strive toward consistency, presumably within the bounds of evidence-based practice, there is room for different strategies of cancer care, based for example on sequencing of surgery, radiation (RT), and chemotherapy (CTX), and the choice/mix of chemotherapeutic agent(s). It becomes ever more important, therefore, to document treatment patterns and to study the efficacy of different patterns on clinical outcomes such as complications, recurrence, and survival. Medical claims and record review are two sources of information used to analyze treatment patterns; both have their limitations. Given the greater convenience and lower costs of claims data, ensuring their comparability with medical records is important.

In describing patterns of care for breast cancer, there are known discrepancies in medical claims compared with chart review or tumor registry data with respect to type of surgery and receipt of CTX and RT. Comparing Medicare claims to Surveillance, Epidemiology, and End Results (SEER) data, the level of agreement for type of surgery was 88.0% for breast-conserving surgery (BCS) and 94.5% for mastectomy and the sensitivities, claims to SEER, were 91.3% and 87.9% for BCS and 96.2% and 96.0% for mastectomy using either inpatient or physician claims, respectively [2]. For determining use of CTX, the sensitivity of Medicare claims to chart review was 91% [3]. In another study [4] there was a high level of agreement between SEER-Medicare claims and National Cancer Institute-supported Patterns of Care Studies (POC) medical chart review data for use of CTX (kappa 0.73), and a sensitivity of Medicare claims to re-abstracted data of 88% for breast cancer. With respect to RT treatment, comparison of Medicare claims with SEER data finds a sensitivity of 93%, claims to SEER data [5] and comparison of SEER-Medicare linked data to claims data report high levels of agreement in lung (88%), prostate (94%), rectal (94%), breast (94%), and endometrial cancers (95%) [6].

The level of agreement between claims and records according to most of these studies seems to be reasonably high. However, there is little evidence in the literature regarding whether strategies of care with multiple components (surgery, RT, CTX) or specific multiple agent chemotherapeutic regimens have as high a level of agreement. The purpose of this study was to examine the level of agreement between the two data sources regarding various treatment patterns for a sample of breast cancer patients. Our study uses cancer registry data augmented by medical record re-abstraction as the gold standard to which claims data are compared. This study advances the literature by comparing claims with records for both single and multiple components of cancer therapy, including examination of specific chemotherapeutic agents.