Medicaid expansion and resource utilization in the emergency department

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Abstract

Background

The Affordable Care Act (ACA) has impacted the insurance mix of emergency department (ED) visits, yet the degree to which this has influenced provider behavior is not clear.

Methods

This was a difference-in-differences (DID) analysis of ED-visit data from five states in 2013 and 2014. Sample states included 3 expanding Medicaid under the ACA, 1 rejecting ACA funding and delaying an eligibility expansion, and 1 with no eligibility change. We included self-pay and Medicaid patients aged 27 to 64 years. A subsample analysis was done for chest pain visits. DID logistic models were estimated for likelihood of admission for given Medicaid-paid ED visits in expansion states as compared to non-expansion states. Among chest pain visits we assessed likelihood given visits resulted in admission or advanced cardiac imaging, where clinician discretion may be more significant.

Results

A total of 8,157,748 ED visits with primary payer Medicaid and self-pay were included, of which 331,422 were for chest pain. The proportion of visits paid for by Medicaid rose in expansion states by between 15.8% and 38.9%. Medicaid eligibility expansion was associated with increased odds of admission (OR 1.070 [95% CI 1.051–1.089]). Among chest pain visits, expansion was associated with increased odds of admission (OR 1.294 [95% CI 1.144–1.464]), but not advanced cardiac imaging (OR 1.099 [95% CI 0.983–1.229]).

Conclusion

Medicaid expansion was associated with small increases in ED visit admissions across the board and among the subgroup of patients presenting with chest pain.

Introduction

The Patient Protection and Affordable Care Act (ACA) provided numerous incentives for state expansion of Medicaid programs in 2014. In particular, the ACA sought to expand eligibility to childless adults up to 133% of the Federal Poverty Line. However, the 2012 Supreme Court ruling in National Federation of Independent Business versus Sebelius rendered significant expansion of Medicaid under the ACA an invalid exercise of Congress's spending power [1], prompting many states to reject expanded Medicaid coverage provided by the ACA. Ultimately, 21 states expanded Medicaid as a result of the ACA at the time of rollout in 2014 [2]. This state-level variation in Medicaid eligibility by income and state provides an opportunity to explore the effects of Medicaid expansion on health care services utilization [3,4].

Much work has focused on how patients' health behavior is affected by newly enrolling in health insurance, especially with respect to acute care and emergency department (ED) visits [[5], [6], [7], [8]]. Prior literature on expanding Medicaid eligibility has not always shown benefit for clinical outcomes [7,8]. In general, though, prior literature has established a benefit to insurance status on healthcare access and even mortality [[9], [10], [11], [12]], and from the ED those with better insurance status are more likely to be admitted to the hospital [13,14].

Controversy remains as to the net effect of statewide Medicaid expansion programs under the ACA on the number of ED visits [[15], [16], [17]], but there is a growing consensus that eligibility expansion did result in a net increase in insurance-payed ED visits [18]. With so much attention payed to patient's choices, and to quality improvement efforts [[19], [20], [21]], there has been comparatively less done to decipher how health care provider behavior is affected when the population payer mix changes (towards public insurance and away from self-pay or no insurance). Specifically, does the provider and system-level management of a given medical condition change with large expansion of a public insurance program? Part of the answer lies with changes in the presenting patients – their acuity, comorbidities, and access to other healthcare and social resources. There may also be a change in the general propensity of providers to admit or discharge, or to perform advanced diagnostic testing.

Provider discretion is often an important driver of variation in utilization [22], and chest pain is among the most common conditions associated with provider variation in testing and admission [23]. Low- and moderate-risk chest pain patients can be discharged without follow up, sent for outpatient testing, or admitted for testing. The effect of expansion on provider or hospital practice patterns is unknown, particularly for discretionary conditions such as chest pain.

The goal of this investigation is to examine the effect of statewide Medicaid expansion under the ACA on hospital admission rates from the ED specifically for the payer groups Medicaid and self-pay. In a subset analysis of chest pain visits among this payer group, where provider discretion in practice may be more significant, we examine the effect of expansion on admission rates and advanced cardiac imaging.

Section snippets

Study design and setting

This was a secondary analysis of existing publicly available data from the Healthcare Cost and Utilization Project (HCUP). We used the State Inpatient Databases (SID), which includes data from inpatient stays including those that were the result of admission from a hospital affiliated ED, and State Emergency Department Databases (SEDD), which include visits to hospital affiliated EDs which did not result in admission to the same institution [24,25]. When combined, these datasets represent all

Characteristics of study subjects

Overall, there were 17,981,410 ED visits for patients aged 27–64 across all five states in 2013 and 2014. 8,157,879 of these were self-pay and Medicaid ED visits, and 331,427 of these were discharged from the ED or hospital with a CCS code for chest pain. Table 1 combines data from our sample with publicly available data from Kaiser Family Foundation [2] on population-level insurance status to depict the percentage of ED visits paid by Medicaid or self-pay alongside the percentage of the

Discussion

Beyond the increased propensity of individuals to visit the ED after insurance enrollment, our study suggests that Medicaid expansion is associated with an increase in hospital admissions. Our study addresses both the broad outcome, likelihood of admission among all ED visits, as well as the narrower case of the common, discretionary condition of chest pain. Notably, although the overall trend in the states studied was towards decreased admission rates and advanced cardiac testing (as seen in

Conclusion

In this analysis of data from five states, Medicaid eligibility expansion after passage of the ACA was associated with increases in hospital-based acute care service utilization, namely admission rates. This finding was consistent with respect to chest pain, a common condition known to have substantial discretionary utilization. This pattern may represent improvements in access to care that result from insurance expansion, financially motivated utilization by providers or a transient increase

Author contributions

PDL, SD, ATJ conceptualized the study and developed the methodology. ATJ performed the analysis and drafted the manuscript. PDL, SD, ATJ, AKV contributed to the revision and editing of the manuscript.

Acknowledgements

This work was supported by the Emergency Medicine Foundation Medical Student Research grant.

References (33)

  • B.D. Sommers et al.

    Changes in self-reported insurance coverage, access to care, and health under the affordable care act

    JAMA

    (2015)
  • D.J. LaPar et al.

    Primary payer status affects mortality for major surgical operations

    Ann Surg

    (2010)
  • V. Chikani et al.

    Association of insurance status with health outcomes following traumatic injury: statewide multicenter analysis

    West J Emerg Med

    (2015)
  • J.P. Ruger et al.

    Association between insurance status and admission rate for patients evaluated in the emergency department

    Acad Emerg Med

    (2003)
  • S. Wilson et al.

    Identifying disparity in emergency department length of stay and admission likelihood

    World J Emerg Med

    (2016)
  • J.M. Pines et al.

    Medicaid expansion in 2014 did not increase emergency department use but did change insurance payer mix

    Health Aff

    (2016)
  • Cited by (6)

    This work was supported by the Emergency Medicine Foundation Medical Student Research grant. This work was presented at American College of Emergency Physicians Scientific Assembly on October 1st, 2018 in San Diego, CA.

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