P72: Association Of Hospital Network Affiliation with Surgical Outcomes and Spending For Complex Cancer: A longitudinal study of hospital mergers and acquisitions from 2010 to 2018

Hospital mergers have doubled over the last decade with over 70% of US hospitals now part of a hospital network. The presumed benefits of hospital consolidation include concentrating volume and expertise, care integration, and investment in quality improvement. However, it remains unknown whether hospital networks have implemented specific strategies to optimize surgical outcomes and costs and realized the theoretical benefits of consolidation.



Methods:

Using 100% Medicare claims data, we identified fee-for-service Medicare patients undergoing elective colon, rectal, lung, or pancreas resection for cancer from 2010 to 2018. Using the American Hospital Association Annual Survey, we ascertained whether a hospital was part of a network and in which year it joined. We longitudinally evaluated the association between risk-adjusted, price-standardized payments, surgical outcomes (risk-adjusted serious complications or mortality), and operative volumes with network affiliation using a difference-in-differences approach.



Results:

We identified nearly 340,000 cancer operations, with 24% occurring at non-network hospitals and 76% at network hospitals. Mean age was 76 years, and 48.4% of the cohort was female. Compared to before joining a network ($27,501, 95%CI:27,119-27,883), there was no difference in spending after a hospital joined a network ($27,724, 95%CI:27,540-27,910). Similarly, there was no difference in mortality or serious complication rates, or overall cancer-specific operative volume after a hospital joined a network (Figure). When assessing hospitals individually, the majority (94%) had no change in spending after joining a network whereas 2.6% had a significant decrease in spending compared to 3.4% which had a significant increase in spending. Compared with hospitals that had increased spending, hospitals that had decreased spending had lower adverse outcome rates (5.6 vs. 6.9, p< 0.001) and higher volume (34 vs 17, p< 0.001).



Conclusions:

In aggregate, hospital network affiliation was not associated with improved surgical spending or outcomes for complex cancer procedures. However, a subset of high-performing networks has implemented care optimization strategies. Understanding the strategies used by these successful mergers may result in generalizable knowledge to allow other networks to also optimize surgical quality and costs.