Treatment Differences by Health Insurance Among Outpatients With Coronary Artery Disease: Insights From the National Cardiovascular Data Registry

Study Questions:

What is the association between insurance status and physicians’ adherence with providing evidence-based treatments for coronary artery disease (CAD)?


Within the Practice Innovation and Clinical Excellence (PINNACLE) Registry of the National Cardiovascular Data Registry (NCDR), the authors identified 60,814 outpatients with CAD from 30 US practices. Hierarchical modified Poisson regression models with practice site as a random effect were used to study the association between health insurance (no insurance, public insurance, or private health insurance) and five CAD quality measures.


Of 60,814 patients, 5,716 patients (9.4%) were uninsured and 11,962 patients (19.7%) had public insurance, whereas 43,136 (70.9%) were privately insured. After accounting for exclusions, uninsured patients with CAD were 9%, 12%, and 6% less likely to receive treatment with a beta-blocker, an angiotensin-converting enzyme inhibitor/angiotensin II receptor blocker (ACE-I/ARB), and lipid-lowering therapy, respectively, than privately insured patients, and patients with public insurance were 9% less likely to be prescribed ACE-I/ARB therapy. Most differences by insurance status were attenuated after adjusting for the site providing care. For example, whereas uninsured patients with left ventricular dysfunction and CAD were less likely to receive ACE-I/ARB therapy (unadjusted relative risk [RR], 0.88; 95% confidence interval [CI], 0.84-0.93), this difference was eliminated after adjustment for site (adjusted RR, 0.95; 95% CI, 0.88-1.03; p = 0.18).


The authors concluded that within this national outpatient cardiac registry, uninsured patients were less likely to receive evidence-based medications for CAD.


This study reported that treatment rates with evidence-based medications in CAD patients differed by insurance status. Uninsured patients were less likely to have been treated with lipid-lowering therapy for CAD, beta-blockers after MI, and ACE-I/ARB therapy in those with left ventricular systolic dysfunction and/or diabetes. Interestingly, most of these differences were eliminated after adjusting for the site at which patients received care, which suggests that treatment differences at the patient level were largely explained by lower rates of medication treatment at sites with higher proportions of uninsured patients. Targeted interventions are needed to improve the quality of care at practices with large numbers of uninsured patients.

Clinical Topics: Atherosclerotic Disease (CAD/PAD)

Keywords: Angiotensin Receptor Antagonists, Risk, Coronary Artery Disease, Ventricular Dysfunction, Insurance, Medically Uninsured, Outpatients, Cardiology, Diabetes Mellitus

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