Elsevier

Annals of Emergency Medicine

Volume 64, Issue 2, August 2014, Pages 107-115.e3
Annals of Emergency Medicine

Health policy/original research
Increased Use of the Emergency Department After Health Care Reform in Massachusetts

https://doi.org/10.1016/j.annemergmed.2014.02.011Get rights and content

Study objective

With implementation of the Patient Protection and Affordable Care Act, 30 million individuals are predicted to gain access to health insurance. The experience in Massachusetts, which implemented a similar reform beginning in 2006, should provide important lessons about the effect of health care reform on emergency department (ED) utilization. Our objective is to understand the extent to which Massachusetts health care reform was associated with changes in ED utilization.

Methods

We compared changes in ED utilization at the population level for individuals from areas of the state that were affected minimally by health care reform with those from areas that were affected the most, as well as for those younger than 65 years and aged 65 years or older. We used a difference-in-differences identification strategy to compare rates of ED visits in the prereform period, during the reform, and in the postreform period. Because we did not have population-level data on insurance status, we estimated area-level insurance rates by using the percentage of actual visits made during each period by individuals with insurance.

Results

We studied 13.3 million ED visits during 2004 to 2009. Increasing insurance coverage in Massachusetts was associated with increasing use of the ED; these results were consistent across all specifications, including the younger than 65 years versus aged 65 years or older comparison. Depending on the model used, the implementation of health care reform was estimated to result in an increase in ED visits per year of between 0.2% and 1.2% within reform and 0.2% and 2.2% postreform compared with the prereform period.

Conclusion

The implementation of health care reform in Massachusetts was associated with a small but consistent increase in the use of the ED across the state. Whether this was due to the elimination of financial barriers to seeking care in the ED, a persistent shortage in access to primary care for those with insurance, or some other cause is not entirely clear and will need to be addressed in future research.

Introduction

The full implementation of the Patient Protection and Affordable Care Act of 2010, including both the individual mandate to purchase insurance and Medicaid expansions set to begin in 2014, will extend health insurance to a projected 30 million people by 2019.1 The act was modeled after similar health care reform legislation that Massachusetts implemented beginning in 2006. The combination of an individual mandate, employer assessments, insurance market reforms, and expansion of publicly subsidized insurance products was designed primarily to reduce the number of Massachusetts residents without health insurance. Recent estimates show that about 1.9% of Massachusetts residents are uninsured2 compared with about 10% before the enactment of health care reform and 16% nationally.3

Editor’s Capsule Summary

What is already known on this topic

The effect of gaining health insurance on emergency department (ED) use is not clear.

What question this study addressed

How does ED use change after mandated health insurance coverage?

What this study adds to our knowledge

ED visits increased after Massachusetts health care reform. The increase was greater in areas of Massachusetts with larger increases in insurance coverage.

How this is relevant to clinical practice

We should expect ED visit rates to increase as the Patient Protection and Affordable Care Act expands subsidized health insurance to millions of low-income Americans.

A looming question for policymakers and administrators is how health care reform will affect the use of health care services and, in particular, patterns of seeking emergency care. The answer to this question may have a profound effect on state and delivery system planning in advance of the widespread increases in insurance coverage that will begin in 2014. The Massachusetts experience provides a unique opportunity to study how implementation of health insurance reform on which the Patient Protection and Affordable Care Act was modeled affected patterns of emergency department (ED) use on a population level. To date, evaluations of the effect of health care reform on ED visits in Massachusetts have revealed conflicting results.4, 5, 6

In this study, we examine changes in ED use that resulted from the implementation of Massachusetts health care reform, using data from a statewide database capturing all ED visits, including those that resulted in hospital admissions or observation stays. Our study design takes advantage of the differential effect of health care reform across the state by comparing changes in ED care at the population level for individuals from areas of the state that were affected the most by health care reform with those from areas that were affected the least. Thus, our method allows us to make stronger inferences about the effect of health care reform on use as opposed to simply tracking use trends over time or making comparisons with states that might differ in other fundamental ways. In addition, we examine changes in use for the population aged 65 years and older, which, because of Medicare coverage, should not have been affected by Massachusetts health care reform. Our major limitation is the use of the frequency of ED visits by the uninsured as an estimate of the true frequency of uninsured individuals in an area. We use this estimate because we did not have access to population-level data on the percentage of individuals without insurance. We compensated for this by using several different modeling strategies to test the robustness of our results. Because attaining insurance typically is associated with increased use of services and because of constraints on access to alternative sites of care outside of the ED, we hypothesized that health care reform would be associated with increased ED use.

Section snippets

Materials and Methods

In 2006, an act providing access to affordable, quality, accountable health care put in place in Massachusetts a series of Medicaid expansions, subsidized insurance offerings, insurance market reforms, safety net alterations, and individual and employer mandates to purchase or provide health insurance. The various components of the reform, implemented in stages between 2006 and 2008, have been previously described in detail4 and are depicted in Figure 1. More details can be found in Appendix E1

Results

For the population younger than 65 years, we studied 4.3 million visits in the 2 years before health care reform, 2.2 million visits during the health care reform period, and 4.5 million visits during the post–health care reform period (Table 1). The population aged 65 years and older included an additional 921,311 visits in the prereform period, 444,180 visits during health care reform, and 919,667 visits in the postreform period. Overall ED visits by the uninsured younger than 65 years

Limitations

There are several limitations to our analyses. The ideal way to study this issue outside the context of a randomized controlled trial would be to obtain insurance coverage data on a defined cohort of patients and compare those who obtain health insurance with those who either did not obtain health insurance or already had health insurance, using a difference-in-differences approach. Such data, however, are unavailable. The statewide data set of ED visits that we used is a next best

Discussion

To our knowledge, this is the first study using complete data on statewide ED visits to demonstrate that the increase in insurance coverage associated with health care reform in Massachusetts resulted in a small but measurable increase in ED visits across the state. Not unexpectedly, these findings were concentrated in areas of the state that were most affected by health care reform and were not present for the population that was covered by Medicare for the entire study period. Our findings

References (21)

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    Most of the increase in the newly insured population was for higher-acuity visits. Despite the ACA’s intention to reduce ED visits, many experts predicted an initial increase in ED visits after insurance expansion under the ACA, based on several studies of pre-ACA state insurance expansions.5-9 For example, the 2008 Oregon Health Insurance Experiment found that uninsured patients randomized to gain Medicaid coverage increased their rates of ED utilization by 41%, including for lower-acuity visits.7

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Please see page 108 for the Editor’s Capsule Summary of this article.

Supervising editor: Melissa L. McCarthy, ScD

Author contributions: PBS, JO, and BEL conceived the study and obtained research funding and data. PBS and XY were responsible for collecting and managing the data. XY analyzed the data. JO provided primary statistical advice. PBS drafted the article, and all authors contributed substantially to its revision. PBS takes responsibility for the paper as a whole.

Funding and support: By Annals policy, all authors are required to disclose any and all commercial, financial, and other relationships in any way related to the subject of this article as per ICMJE conflict of interest guidelines (see www.icmje.org). The authors have stated that no such relationships exist and provided the following details: Dr. Smulowitz received a grant from the Charles A. King Trust Postdoctoral Research Fellow Program and the Eleanor and Miles Shore Fellowship Program for Scholars in Medicine.

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