The role of national cancer institute-designated cancer center status: Observed variation in surgical care depends on the level of evidence

Objective: We sought to evaluate differences in guideline concordance between National Cancer Institute (NCI)-designated and other centers and determine whether the level of available evidence influences the degree of variation in concordance. Background: The National Cancer Institute recognizes centers of excellence in the advancement of cancer care. These NCI-designated cancer centers have been shown to have better outcomes for cancer surgery; however, little work has compared surgical process measures. Methods: A retrospective cohort study was conducted using Surveillance, Epidemiology and End Results registry linked to Medicare claims data. Fee-for-service Medicare patients with a definitive surgical resection for breast, colon, gastric, rectal, or thyroid cancers diagnosed between 2000 and 2005 were identified. Claims data from 1999 to 2006 were used. Our main outcome measure was guideline concordance at NCI-designated centers compared to other institutions, stratified by level of evidence as graded by National Comprehensive Cancer Network guideline panels. Results: All centers achieved at least 90%, and often 95%, concordance with guidelines based on level 1 evidence. Concordance rates for guidelines with lower-level evidence ranged from 30% to 97% and were higher at NCI-designated centers. The adjusted concordance ratios for category 1 guidelines were between 1.02 and 1.08, whereas concordance ratios for guidelines with lower-level evidence ranged from 0.97 to 2.19, primarily favoring NCI-designated centers. Conclusions: When strong evidence supports a guideline, there is little variation in practice between NCI-designated centers and other hospitals, suggesting that all are providing appropriate care. Variation in care may exist, however, for guidelines that are based on expert consensus rather than strong evidence. This suggests that future efforts to generate needed evidence on the optimal approach to care may also reduce institutional variation.