Researchers Find Link Between Cardiologist Integration in Networks and Care Intensity
Could hospital-physician integration actually be leading to excessive delivery of certain cardiac procedures? A team of researchers thinks so. Indeed, the title of their article, “Hospital-Physician Integration Is Associated With Greater Use Of Cardiac Catherization And Angioplasty,” which was published in the May issue of Health Affairs, goes to the heart of the matter.
As the researchers—Brady Post, Ph.D., Farbod Alinezhad, Sunit Mukherjee, M.D., and Gary J. Young, Ph.D., J.D., write in their abstract, “In the US in recent years, hospital-physician integration has become a dominant form of consolidation in health care. This transition away from independent practice has raised questions about whether hospital-employed physicians may be more likely than independent physicians to refer patients to high-intensity, hospital-based services. We used Medicare claims data from the period 2013–20 to identify patients who received a new diagnosis of stable angina, a common cardiovascular condition that entails clinical discretion in treatment choice. Using linear probability models and an instrumental variables model, we found that patients whose care was managed by a hospital-integrated cardiologist were no more likely to receive stress tests (an office-based procedure) than those whose care was managed by an independent cardiologist. However, these patients were much more likely to receive high-intensity, hospital-based coronary interventions. These results suggest that hospital-physician integration is an important factor in the intensity of treatment received by patients with stable angina. Policy makers may see these findings as additional impetus for more aggressive antitrust enforcement of integrated arrangements between hospitals and physicians and for other regulatory or payment mechanisms that might deter hospitals from using such arrangements to promote high-intensity treatment unnecessarily.”
The team of researchers used national Medicare claims data from the period 2013–20 to identify patients newly diagnosed with stable angina, examining the data to uncover differences in patterns of care for patients treated by hospital-integrated cardiologists and those treated by independent (that is, non–hospital integrated) cardiologists. As they write in the article, “Our research question was, Do patients newly diagnosed with stable angina receive different care under the clinical management of hospital-integrated cardiologists compared with independent cardiologists?”
The researchers looked at the following variables: “patients’ use of cardiac stress testing, cardiac catheterization, and coronary angioplasty in the twelve months after their diagnosis,” noting that “These services are often performed after a diagnosis of stable angina to assess the severity of the condition… and treat the underlying cause of symptoms.” And the key independent variable was whether patients’ attributed cardiologists were independent or hospital integrated during the twelve months after diagnosis. That said, the researchers concede in their article that one weakness in their analysis involved the fact that claims data lacks clinical information such as the severity of coronary disease. Also, the study focused solely on patients enrolled in traditional Medicare, not in Medicare Advantage.
That having been said, the researchers explain their findings that “The integration status of patients’ cardiologists was correlated with patients’ receipt of cardiac stress testing, cardiac catheterization, and angioplasty in the first twelve months after diagnosis (exhibit 1). In unadjusted analysis we observed that rates of cardiac stress testing were somewhat higher among patients of independent cardiologists (32 percent and 30 percent among independent and integrated cardiologists, respectively). In contrast, patients treated by integrated cardiologists had higher rates of cardiac catheterization (33 percent of independent versus 38 percent of integrated cardiologists) and coronary angioplasty (11 percent of independent versus 14 percent of integrated cardiologists).”
Thus, their core conclusions: “Patients of integrated cardiologists were ostensibly as healthy as patients treated by independent cardiologists, which was especially notable, as other research has shown that diagnoses among patients of integrated physicians are coded more aggressively than those of equivalent patients of independent physicians.33 Patients of integrated cardiologists appeared slightly less likely to receive a cardiac stress test, which is a low-tech diagnostic technique. However, patients of integrated cardiologists were significantly more likely to receive cardiac catheterization, which is a higher-tech procedure, and angioplasty, which is a minimally invasive procedure that, although safe and effective, still entails risks. The rate of catheterizations followed by angioplasties was slightly higher among integrated cardiologists, as was the probability of patients receiving a catheterization in the absence of any stress test. Together, these results imply that hospital-cardiologist integration may tilt treatment mix toward higher-intensity services.”
Given all that, they conclude that “Our study equips policy makers with new insights as they assess the advantages and disadvantages of a more consolidated health care system. Increased consolidation in health care has become a national concern: The Biden administration has identified health care consolidation as a priority area,38 and the Federal Trade Commission has opened an investigation into hospital-physician integration specifically.39 The findings of our study will aid policy makers in anticipating whether increases in the prevalence of hospital-physician integration may induce physicians to undertake different treatment approaches with potentially important implications for the cost and quality of patients’ care.”
Brady Post, Ph.D., is an assistant professor in the Department of Health Sciences at Northeastern University (Boston). Farbod Alinezhad is a Ph.D. student in population health and health economics at Northeastern University. Sunit Mukherjee, M.D., is an interventional cardiologist at Lawrence General Hospital (Lawrence, Mass.). Gary J. Young, Ph.D., J.D., is director of the Northeastern University Center for Health Policy and Healthcare Research, and a professor of strategic management and healthcare systems at Northeastern University.
