Differential receipt of sentinel lymph node biopsy within practice-based research networks.

Abstract

102 Background: Sentinel lymph node biopsy (SLNB) is a quality indicator for breast cancer care. Provider-based research networks (PBRNs) promote diffusion of innovations like SLNB into clinical practice; however, evidence is limited. We examined the diffusion of SLNB for early-stage breast cancer through the Community Clinical Oncology Program (CCOP), a community-based PBRN and its interaction with medical school affiliation. Methods: We identified women undergoing breast conserving surgery with axillary staging for stage I or II breast cancer between January 2000 and December 2003 using Surveillance Epidemiology and End Results-Medicare data (n=6,226). The primary outcome was receipt of SLNB vs. ALND. Exposure was constructed by combining information on the CCOP affiliation of the preforming physician with the medical school affiliation of the hospital. Covariates included race, age, marital status, education, Medicaid eligibility, comorbidity, tumor grade, stage, estrogen receptor status, year of diagnosis, SEER region, and NCI cancer center designation. Multivariable generalized linear modeling with generalized estimating equations was used to measure association between CCOP exposure and receipt of SLNB. Results: Women who saw a CCOP physician at a hospital affiliated with a medical school had a three-fold increase in odds of receiving SLNB compared to non-CCOP women. In contrast, the odds of SLNB were equivalent when looking in women who were seen by a CCOP physician but differed only by their hospital affiliation. Conclusions: Women seen by CCOP-affiliated physicians were more likely to receive SLNB; while medical school affiliation did appear to significantly impact receipt. Innovative, high-quality cancer care can be facilitated PBRNs such as the NCI CCOP program. There must be mechanisms by which providers are exposed to advances in clinical practice outside of organizational affiliations. [Table: see text]