Expansion of Invasive Cardiac Services in the United States
Background—The number of hospitals offering invasive cardiac services (diagnostic angiography, percutaneous coronary intervention [PCI], and coronary artery bypass grafting [CABG]) has expanded, yet national patterns of service diffusion and their effect on geographic access to care are unknown.
Methods and Results—Retrospective cohort study of all hospitals in fee-for-service Medicare, 1996-2008. Logistic regression identified the relationship between cardiac service adoption and the proportion of neighboring hospitals within 40 miles already offering the service. From 1996- 2008, 397 hospitals began offering diagnostic angiography, 387 PCI, and 298 CABG (increasing the proportion with services by 3%, 11%, and 4% respectively). This capacity increase led to little new geographic access to care; the population increase in geographic access to diagnostic angiography was 1 percentage point; PCI 5 percentage points, and CABG 4 percentage points. Controlling for hospital and market characteristics, a 10 percentage point increase in the proportion of nearby hospitals already offering the service increased the odds by 10% that a hospital would add diagnostic angiography (OR: 1.102; 95% CI: 1.018, 1.193), increased the odds by 79% that it would add PCI (OR: 1.794, 95% CI: 1.288, 2.498), and had no significant effect on adding CABG (OR 0.929, 95% CI, 0.608, 1.420).
Conclusions—Hospitals are most likely to introduce new invasive cardiac services when neighboring hospitals already offer such services. Increases in the number of hospitals offering invasive cardiac services have not led to corresponding increases in geographic access.
- diffusion of innovation
- geographic variation
- access to care
- health policy
- health services research
- cardiovascular intervention
- Received December 28, 2012.
- Revision received May 30, 2013.
- Accepted June 25, 2013.