Department of Health Policy, Vanderbilt University School of Medicine, Nashville, TN.
School of Public and Environmental Affairs, Indiana University, Bloomington, IN.
Ann Emerg Med. 2017 Aug;70(2):215-225.e6. doi: 10.1016/j.annemergmed.2017.03.023. Epub 2017 Jun 19.
We assess whether the expansion of Medicaid under the Patient Protection and Affordable Care Act (ACA) results in changes in emergency department (ED) visits or ED payer mix. We also test whether the size of the change in ED visits depends on the change in the size of the Medicaid population.
Using all-capture, longitudinal, state data from the Agency for Healthcare Research and Quality's Fast Stats program, we implemented a difference-in-difference analysis, which compared changes in ED visits per capita and the share of ED visits by payer (Medicaid, uninsured, and private insurance) in 14 states that did and 11 states that did not expand Medicaid in 2014. Analyses controlled for state-level demographic and economic characteristics.
We found that total ED use per 1,000 population increased by 2.5 visits more in Medicaid expansion states than in nonexpansion states after 2014 (95% confidence interval [CI] 1.1 to 3.9). Among the visit types that could be measured, increases in ED visits were largest for injury-related visits and for states with the largest changes in Medicaid enrollment. Compared with nonexpansion states, in expansion states the share of ED visits covered by Medicaid increased 8.8 percentage points (95% CI 5.0 to 12.6), whereas the uninsured share decreased by 5.3 percentage points (95% CI -1.7 to -8.9).
The ACA's Medicaid expansion has resulted in changes in payer mix. Contrary to other studies of the ACA's effect on ED visits, our study found that the expansion also increased use of the ED, consistent with polls of emergency physicians.
我们评估《患者保护与平价医疗法案》（ACA）扩大医疗补助计划是否会导致急诊部（ED）就诊次数或 ED 支付者构成发生变化。我们还检验 ED 就诊次数的变化幅度是否取决于医疗补助计划覆盖人群的变化幅度。
我们利用美国医疗保健研究与质量局的 FastStats 项目提供的全捕获、纵向州级数据，实施了差异中的差异分析，比较了 2014 年实施医疗补助计划扩大的 14 个州和未实施扩大的 11 个州，人均 ED 就诊次数以及 ED 就诊支付者（医疗补助计划、无保险和私人保险）构成的变化情况。分析中控制了州级人口统计学和经济特征。
我们发现，2014 年之后，医疗补助计划扩大的州，每 1000 人口的总 ED 使用量增加了 2.5 次就诊（95%置信区间为 1.1 到 3.9）。在可衡量的就诊类型中，与损伤相关的就诊和医疗补助计划登记人数变化最大的州，ED 就诊次数的增加幅度最大。与未扩大医疗补助计划的州相比，在扩大医疗补助计划的州，ED 就诊中由医疗补助计划支付的比例增加了 8.8 个百分点（95%置信区间为 5.0 到 12.6），而无保险的比例下降了 5.3 个百分点（95%置信区间为 -1.7 到 -8.9）。
ACA 的医疗补助计划扩大导致了支付者构成的变化。与其他研究 ACA 对 ED 就诊影响的研究相反，我们的研究发现，该扩展还增加了 ED 的使用，这与急诊医师的民意调查结果一致。
