In heart failure, higher volumes point to lower mortality

Patients with heart failure (HF) may have a lower risk of dying if they are treated by high-volume physicians, according to findings published online Aug. 7 in Circulation: Heart Failure. The study found an association between high physician volume and lower mortality among HF patients, which was especially strong in lower-volume hospitals and for physicians who are not cardiologists.

“We don't know exactly why this is the case—whether it's about high-volume physicians being better at managing the heart failure itself, or at recognizing and treating complications, or whether these physicians are more compliant with guidelines,” lead author Karen E. Joynt, MD, MPH, of Brigham and Women’s Hospital in Boston, told Cardiovascular Business.

The researchers used 2009 Medicare inpatient data to review all HF admissions to U.S. acute care hospitals. Their selected outcomes were 30-day mortality, 30-day readmissions and costs per hospitalization. Their sample included 78,227 physicians and 471,612 patient discharges.

Patients with the highest-volume physicians had an 8.9 percent mortality rate compared with a 9.7 percent rate in the group of patients with lower-volume physicians.

The study also found physician volume linked to discharge-related costs. Higher-volume physicians incurred higher costs per discharge ($8,982 vs. $8,731), a relatively small difference. Cardiologists, whether high-volume or low-volume, had the costliest discharges, which could be explained by their more frequent use of higher-costing, higher-technology therapies.

The patients of highest-volume physicians also had higher readmission rates (25.8 percent vs. 21.5 percent), which Joynt explained was not a surprising finding.

“This is quite consistent with other studies that show that there is an inverse relationship between mortality and readmissions for heart failure at the hospital level,” Joynt explained. “This study now extends that finding to the physician level. We suspect this is because the high-volume physicians keep their sickest patients alive longer, and they are therefore more often readmitted, but we don't know for sure.”

Physician specialty also played a role in determining the relationship between mortality and physician volume. It was weaker for cardiologists than it was for other specialists or generalists.

“This means that, for non-cardiologist physicians, experience is even more important,” Joynt said. “Cardiologists have gotten a lot of training in how to treat heart failure, so even if they don't care for heart failure patients every day, they may be more prepared to deal with this condition. For physicians without extra training in cardiology, seeing a lot of heart failure patients seems to be even more important in terms of patients' outcomes.”

Their findings, they wrote, should encourage further study of the reasons behind the relationship between physician volume and the various outcomes in their research.

“Since roughly half of the patients in our study were cared for by physicians who were not in the highest-volume group, and nearly 82% were cared for by non-cardiologist physicians, this could potentially have significant national impact,” they wrote. “If high-volume physicians use different diagnostic tests or alternative treatment strategies, identifying those and finding ways to increase their use among low-volume physicians would be helpful.”