Purpose: When a major study finds that a widely used medical treatment is no better than a less expensive alternative, do physicians stop using it? The COURAGE trial (NEJM 2007) found that percutaneous coronary intervention (PCI) is no better than an inexpensive regimen of medical therapy for patients with stable angina. We examine the impact of COURAGE on PCI use.
Methods: We developed a theoretical model of the impact of comparative effectiveness research on costs. The impact depends on: the difference in prices between comparison treatments, current practice patterns, and the impact of evidence on practice patterns. We hypothesize that physicians paid via fee-for-service will be less responsive to studies that recommend abandoning profitable treatments. We show that under these conditions, the expected value of a potential CER study on costs may be positive (i.e. cost-increasing) even if a finding for the less expensive treatment is more likely. The COURAGE trial affords an opportunity to examine how practice patterns change in response to “negative” results. We examine the impact of COURAGE on use of PCI from 2006 to 2009 using 100% patient discharge samples from hospitals in 5 large states (AZ, CA, FL, MA, NJ), Veterans Administration (VA) hospitals, and English hospitals. US community cardiologists are paid via fee-for-service. VA and English cardiologists are salaried.
Results: The figure shows trends in PCI volume. PCI volume in patients with stable angina declined by 19% is US community hospitals and 14% in VA hospitals from 2006 to 2007. However, many patients with stable angina continue to receive PCI as primary therapy. There was no decline in PCI volume in England, possibly reflecting lower baseline use, pent-up demand, and expansions in PCI capacity over this period.
Conclusions: Comparative effectiveness research can reduce costs, but savings will not be fully realized if physicians are reluctant to abandon profitable treatments. We do not find support for the hypothesis that fee-for-service medicine blunted the impact of COURAGE in the US. Increasing use of medical therapy may require switching from a procedural-based system to a more integrated approach (e.g., accountable care organizations).