Poster #82 - Impact of percutaneous coronary intervention facility openings on post-procedure outcomes by insurance type

• In Event: Friday Poster Reception

Abstract

Introduction
Timely percutaneous coronary intervention (PCI) is life-saving for heart attack patients. The number of PCI-capable US hospitals has increased substantially since 2000. Key concerns include widening access disparities for high-quality PCI between low-income and affluent patients and increases in discretionary PCIs. Because private insurers tend to pay higher rates than Medicare, and Medicare pays higher than Medicaid, these financial incentives may influence which patients receive PCI and subsequent health outcomes.

Objectives
We evaluated whether PCI openings near a community differentially affected post-procedure outcomes across three insurance types: (1) Medicare, (2) Medicaid or indigent, and (3) privately insured (including self-pay and other). We further examined whether outcome differences were driven by shifts in patient risk profiles. Outcomes included 30-day unscheduled readmissions, 30-day post-PCI adverse events, and 30-day mortality.

Data and Methods
We used 2011—2022 nonpublic all-payer patient discharge and facility data from the California Department of Health Care Access and Information. We linked 564,445 PCI procedures in the study period to a community-level driving time database. We stratified the analysis into two groups: (1) procedures with a primary diagnosis of acute myocardial infarction (AMI) or unstable angina (AMI cohort), as a proxy for guideline-directed PCI, and (2) all remaining procedures (non-AMI cohort), as a proxy for discretionary PCI.

Using a difference-in-differences framework, we examined the outcome changes associated with community-level PCI openings within each insurance type. An indicator equaled 1 on and after the year a community experienced a PCI opening within a 30-min driving time.

To examine whether outcome changes were driven by shifts in patient profiles, we compared results between two models. Model 1 controlled for community and year fixed effects, the transition of ICD codes from version 9 to 10, and patient demographics. Model 2 additionally controlled for patients’ age and comorbidities.

Results
Among the AMI cohort receiving PCI, only Medicaid or indigent patients had a decrease in 30-day unscheduled admissions when exposed to PCI openings (Model 1: 1.44 percentage-point [ppt], 5.7% relative; Model 2: 1.16 ppt, 4.6% relative).  

Among the non-AMI cohort receiving PCI, Medicaid or indigent patients had a drop in 30-day unscheduled readmissions when exposed to PCI openings (Model 1: 1.65 ppt, 9.4% relative; Model 2: 1.17 ppt, 6.6% relative). Medicare (0.63 ppt, 14.6% relative) and privately insured (0.49 ppt, 11.3% relative) patients showed a decrease in 30-day post-PCI adverse events in Model 1. This decrease narrowed for Medicare patients (0.52 ppt, 12% relative) but became insignificant for privately insured in Model 2. While Model 1 showed no mortality changes, Model 2 revealed an increase in 30-day mortality for Medicaid or indigent (0.36 ppt, 21% relative) and privately insured (0.23 ppt, 13.5% relative) patients.

Conclusions
PCI openings may improve care coordination for Medicaid or indigent patients regardless of underlying diagnoses. However, among the non-AMI cohort receiving PCI, disparities in post-PCI adverse events and 30-day mortality may widen between Medicaid and Medicare patients. Additionally, PCI expansion may shift the non-AMI patient composition toward lower-risk individuals.

Author

• Xiaodan Liang, National Bureau of Economic Research
  Presenting Author