Insurance expansion does not pose risk to people already with coverage

Does expanding health insurance result in adverse consequences for those already with coverage? No.

The Department of Health and Human Services estimates that the Affordable Care Act has expanded access to preventive services to as many as 71 million people.  Some have postulated that this rapid expansion of coverage may have negative spillover effects such as increasing wait times and decreasing access to primary care for patients already with insurance.  To investigate these potential spillover effects, the authors analyzed rates of preventable hospital conditions before and after the 2006 insurance expansion in the State of Massachusetts.

The investigators examined two sets of conditions: (1) those likely to show a reduction in incidence with high-quality outpatient care (e.g. dehydration, bacterial pneumonia, and diabetic complications) and  (2) “marker conditions” unlikely to be impacted by the availability of primary care (e.g. hip fracture and acute myocardial infarction).

The study used patient-level Medicare claims data on 3.2 million enrollees.  The authors then applied difference-in-difference methodology to account for secular trends in hospitalization rates.  As a comparison group, the authors selected a group of Northeastern states with a similar density of primary care physicians – Connecticut, Maine, New Hampshire, Rhode Island, and Vermont.

This study found no difference in preventable hospitalizations attributable to the expansion of insurance in Massachusetts.  The authors conducted a sensitivity analysis on two groups who are particularly vulnerable to reductions in access to care – African-Americans and patients older than 80 years of age.  As with the primary analysis, there were no measurable effects after the expansion in either at risk group.

The most significant limitation of the study was an inability to measure increases in wait time after the insurance expansion.

Commentary

Opponents of insurance expansion under the Affordable Care Act (ACA) have argued that it will create significant delays and reduction in quality as the system struggles to meet the demand from newly insured patients.  This study has provided significant empirical data to inform policymakers on this issue.

Most importantly, – at least with respect to hospitalizations.  Secondly, it provides a measuring stick by which to judge any spillover effects of the Affordable Care Act on the national level.

However, this study still leaves several questions left unanswered.  Since the majority of health care is provided in the outpatient setting, what is the impact of insurance expansion on the ability to obtain an outpatient primary care appointment?  Since the overwhelming majority of the American population is not covered by Medicare, what is the impact of insurance expansion on these patients? Can this adequately be extrapolated from these data?  The answer to these questions are crucial in uncovering any unintended consequences of the ACA on currently insured Americans.

Joynt, KE, et al. Health Affairs. 2013; 32 (3): 571-578.

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Andrew A. Gonzalez, MD, JD, MPH