CardioExchange Archive

In a new study published in the Journal of the American College of Cardiology, Smolderen et al examine the association between insurance status and physicians’ patterns of prescribing evidence-based therapies for coronary artery disease (CAD).

Analyzing the Practice Innovation and Clinical Excellence (PINNACLE) Registry of the National Cardiovascular Data Registry (NCDR), the authors found that: (1) uninsured patients with CAD were 9%, 12%, and 6% less likely to receive treatment with a beta-blocker, an angiotensin-converting enzyme (ACE) inhibitor/angiotensin II receptor blocker (ARB), and lipid-lowering therapy, respectively, than were privately insured patients; (2) patients with public insurance were 9% less likely to be prescribed ACE inhibitor/ARB therapy; and (3) most differences by insurance status were attenuated after adjusting for the site providing care. CardioExchange’s John Ryan interviewed authors Kim Smolderen and Paul Chan about these findings.

Ryan: You observe that treatment differences are largely explained by “lower rates of medication treatment at sites with higher proportions of uninsured patients.”  What do you feel is the reason that these sites with large numbers of uninsured patients have lower rates of treatment?

Smolderen and Chan: Although we did not have data within PINNACLE to account for site-level differences in care, there may be several explanations for our findings.  First, clinics with high proportions of uninsured patients are frequently overbooked and inadequately staffed.  As a result, patients at these clinics may have less “face time” (i.e., shorter clinic time slots) with providers than at other practices, thus resulting in less comprehensive care for their CAD.  Second, uninsured patients may not have sufficient funds to acquire some of their CAD medications (including generics), which may indirectly influence physician-prescribing behavior.  And third, uninsured patients often have to contend with other non-medical (e.g., social, psychological, and economic) issues, and physicians may view these as higher priorities for certain patients than meeting established performance measures for CAD.

Ryan: How would you suggest this discrepancy be best addressed?

Smolderen and Chan: We need a restructuring of medical reimbursement in the U.S. health care system.  First, universal access to primary health care for all patients is essential.  The recently passed Affordable Health Care Act is an important step in the right direction, but this law may not go far enough, and many millions will remain uninsured even with its full implementation starting in 2014.  Second, more robust economic incentives (e.g., federal loan repayment) to encourage physicians to work with underserved populations will increase the work force needed in many of these practices with high proportions of uninsured patients.  In doing so, many of these previously under-staffed clinics can now devote adequate time during patient encounters to address the multiple medical needs of their patients.  Third, until such changes are in place, development of strong on-site prescription assistance programs that utilize available federal and state funding and improvement of provider awareness of such programs at their clinics would facilitate more universal patient access to evidence-based medications for CAD.

Ryan: Were you surprised that treatment of patients with public health insurance was similar to those with private insurance?

Smolderen and Chan: Yes, we were surprised.  We had anticipated a graded relationship by insurance status, with treatment rates for publicly insured patients between those of privately and uninsured patients.  The fact that the unadjusted rates of publicly insured patients mirrored those of privately insured patients may suggest that providing any insurance (public or private) translates into better delivery of CAD care.  Our findings would suggest that the mere extension of insurance (through exchanges or Medicaid) for ~10% of the U.S. population in the Affordable Care Act will likely increase rates of evidence-based CAD treatment of previously uninsured patients to the levels of privately insured patients.

Ryan: Based on your work, ACE inhibitors or ARBs were prescribed in 73% of patients with left ventricular systolic dysfunction and/or diabetes mellitus. What do you feel contributes to failure to prescribe ACE inhibitors/ARBs to over a quarter of these patients?

Smolderen and Chan: Medication cost may play a role.  Although generic versions of ACE inhibitors have been available for years, for patients who cannot take these medications, the cost of ARBs may be a barrier, as generic ARBs have not been available until the past year.  It may also be because the evidence supporting the use of ACE inhibitors and ARBs is the most recent, and their current rates reflect the typical time frame for trial evidence to diffuse into routine practice.  Finally, treatment with ACE inhibitor and ARB medications require some monitoring (i.e., electrolytes and renal function), and it is not clear if additional monitoring presents barriers to treatment.