E392: Quality of Major Cancer Surgery in Healthcare Mega-Systems: How Big is Too Big?

Clinical outcomes vary widely among health systems, which now provide nearly 90% of inpatient care in the US. Although many systems have a local or regional presence, a growing number are larger and may span multiple states. Increasing system size may both facilitate and hinder quality improvement. We sought to compare the quality of major cancer surgery performed by systems of varying sizes.

Methods: We evaluated outcomes for Medicare beneficiaries undergoing colon, rectum, lung, pancreas, or esophagus resection for cancer from 2016 to 2020. Hospitals were assigned to health systems using the Agency for Healthcare Research and Quality Compendium of U.S. Health Systems. Systems were categorized as “small” (2-5 hospitals), “large” (6-19 hospitals), or “mega” (20+ hospitals). Outcomes including 30-day operative mortality, serious complications, and failure to rescue were risk- and reliability-adjusted using a multilevel logistic regression model accounting for patient and hospital characteristics and clustering of outcomes.

Results: The analytic cohort included 330,858 patients (172,825 colon, 30,758 rectum, 98,440 lung, 22,362 pancreas, and 6,473 esophagus). Patients were evenly distributed among 199 small systems (103,346 patients, 31%), 85 large systems (117,364 patients, 35%), and 19 mega-systems (110,148 patients, 33%). The adjusted 30-day mortality rate in mega-systems was 4.6%, versus 3.5% in small systems and 3.6% in large systems (P< .001, Figure 1). Other outcomes followed a similar trend, with mega-systems performing worse. Mega-systems performed more cases per year compared with small and large systems (1593 vs 151 vs 341, P< .001), but fewer cases per hospital (51 vs 85 vs 85, P< .001). Patients in mega-systems were less likely to be treated at teaching hospitals (11% vs 41% vs 39%, P< .001) or Commission on Cancer hospitals (64% vs 80% vs 81%, P< .001). Patients in mega-systems were also more likely to be treated in a for-profit hospital (34% vs 0% vs 3%, P< .001).

Conclusions: For major cancer operations, smaller, more geographically concentrated health systems achieved superior outcomes compared with mega-systems. Understanding the characteristics of high- and low-quality health systems may guide strategies to improve the quality of surgical care.