Coronary Artery Bypass Graft Survives Pay-for-Performance

As the nation tries to cut its health care costs, critics of reform have worried that some patients who need expensive though risky procedures like coronary artery bypass graft surgery (CABG) might not get them.

But a new Harvard School of Public Health study could allay those fears.

According to study results published in Circulation: Cardiovascular Quality and Outcomes, Arnold Epstein, MD and colleagues found that 255 hospitals participating in a federal Centers for Medicare and Medicaid Services (CMS) quality improvement program did not limit patients’ access to such surgery.

The findings “should be reassuring to those concerned about a negative effect from P4P [pay-for-performance] on access to care,” the researchers wrote.

At issue in the study was whether these initiatives, in which CMS offers participants financial rewards for meeting sets of quality metrics, would also encourage hospitals to do fewer surgical procedures where patients face higher risk of death or poor outcomes.

CMS has been testing the effectiveness of P4P in demonstration programs since 2003, the authors wrote.

The largest of these was the Premier Hospital Quality Incentive Demonstration (Premier HQID), in which 421 hospitals agreed to meet quality benchmarks set by CMS for several treatments and procedures offered Medicare patients, including CABG. The aim was to lower mortality rates while cutting costs—a program that evolved into the federal “value-based purchasing” program introduced in Oct. 2012.

To determine whether the new system would mean some patients would be denied high-cost CABG out of hospitals’ attempts to lower their surgical death rates, the researchers compared the performance of hospitals in the Premier HQID with those of a representative national sample of hospitals not participating in the program.

The comparison group reported outcomes through the Hospital Quality Alliance.

“We expected that [CABG] rates at Premier hospitals would decrease more over time,” the authors wrote, as those facilities tried “to avoid high mortality rates and consequent financial penalties.”

Though the control group was larger than the Premier group (more than 500,000 patients vs. about 92,000) they were matched for patient demographics and severity of disease. They found that the overall use of CABG declined in both groups, with no major difference between hospitals in the P4P project and the control group. One reason for the decline was the rising popularity of less invasive percutaneous intervention procedures, the researchers wrote. The study period went from 2003 to 2009.

But since hospitals in the study were also given financial incentives to reduce mortality in patients with acute myocardial infarction (AMI) they appeared to perform CABG whenever it was medically indicated, the team found. That may have a cancelled out any incentive to avoid the procedure.

“In patients with AMI for whom CABG was clearly the treatment of choice, financial incentives for AMI mortality may have acted to reduce risk-aversive behavior,” they concluded.