Payment Increases and Physician Supply of Care for Medicaid Beneficiaries

 描述(由申请人提供)：这个项目测试支付增加如何影响医生对医疗补助患者的护理供应。这项研究使用了一个自然的实验，在这个实验中，由于《平价医疗法案》(Affordable Care Act)中的一项条款将联邦医疗补助(Medicaid)初级保健费用提高到联邦医疗保险(Medicare)的水平，初级保健服务的医疗补助报销平均增加了73%。根据医生对医疗补助和医疗保险的比率，这一政策变化对各州医生的影响不同。我将使用这个政策实验来测试医生是否通过增加他们为医疗补助患者提供的护理来应对支付增加--正如athenaHealth，Inc.汇编的索赔数据库和电子健康记录数据中所观察到的那样。《平价医疗法案》极大地增加了获得保险的机会，部分是通过州医疗补助的扩大。覆盖范围的扩大引发了人们对获得护理的担忧，特别是在医生历来不太可能接受医疗补助患者的情况下。增加初级保健的医疗补助报销是为了激励医生治疗更多的医疗补助患者。我提议的研究将直接测试这项政策的有效性，并为正在进行的关于增加医疗补助报销是否是确保获得医疗补助的有效战略的辩论提供信息。如果医生对支付增加的反应是改变他们对医疗补助患者的医疗保健供应，这种变化可能会采取几种可能的形式。首先，目前治疗医疗补助患者的医生可能会治疗更多。AIM 1将使用改进的差值(DD)框架和结果测量来测试这一点，该框架和结果测量将医疗补助患者作为医生小组的份额和医生计划的总预约时间进行量化。DD框架通过比较Medicaid初级保健支付增加之前和之后的医生医疗供应，以及因其所在州的前期费用计划慷慨而经历不同价格冲击的医生，来确定支付增加的影响。内科医生和时间固定效应对照：内科医生之间的基线结果差异和时间趋势。支付的增加也可能激励那些以前将医疗补助患者排除在外的医生开始接受他们。如果医生在这段时间内接受了任何医疗补助患者，AIM 2将使用等于1的二元结果衡量标准来测试这一点。估计方程类似于目标1，但由于因变量的二元性，将使用Logistic回归。最后，新患者和现有患者对付费增加的体检反应可能有所不同。目标3侧重于改变接受医疗补助的新患者获得医生服务的机会。为了评估付费的增加是否为新患者提供了更多的机会，我将测试医生小组中以前没有看过的患者的百分比是否有所增加，这是通过为新患者而不是现有患者的办公室就诊保留的程序代码集合来确定的。

 DESCRIPTION (provided by applicant): This project tests how payment increases affect physician supply of care for Medicaid patients. The study uses a natural experiment in which Medicaid reimbursement for primary care services increased by an average of 73 percent, as a result of a provision in the Affordable Care Act that increased Medicaid primary care fees to Medicare levels. This policy change affected physicians differently across states, based on their Medicaid-to-Medicare ratios. I will use this policy experiment to test whether physicians respond to payment increases by increasing how much care they provide to Medicaid patients - as observed in a database of claims and electronic health record data compiled by athenahealth, Inc. The Affordable Care Act greatly increased access to insurance, partially through state Medicaid expansions. Expanded coverage has generated concern about access to care, particularly as physicians have historically been less likely to accept Medicaid patients. The increase in Medicaid reimbursement for primary care was designed to incentivize physicians to treat more Medicaid patients. My proposed research will directly test the efficacy of this policy and inform an ongoing debate about whether increasing Medicaid reimbursement is an effective strategy for ensuring access. If physicians respond to a payment increase by changing their supply of medical care for Medicaid patients, this change may take a few possible forms. First, physicians who currently treat Medicaid patients may treat more. Aim 1 will test for this, using a modified difference-in-differences (DD) framework and outcome measures that quantify Medicaid patients as a share of a physician's panel and a physician's total scheduled appointment time. The DD framework identifies the effects of payment increases by comparing physician supply of medical before and after the Medicaid primary care payment increase, and across physicians that experienced different price shocks as a result of the pre-period fee schedule generosity in their state. Physician and time fixed effects control for baseline differences in outcomes among physicians and time trends. A payment increase may also incentivize physicians who had previously excluded Medicaid patients to begin accepting them. Aim 2 will test for this using a binary outcome measure equal to one if the physician accepted any Medicaid patients during that time period. The estimating equation is similar to Aim 1, but will use logistic regression, due to the binary nature of the dependent variable. Finally, physicia response to a payment increase may differ by new versus established patients. Aim 3 focuses on changes in access to physician services for new patients with Medicaid. To assess whether increased payment resulted in greater access for new patients, I will test whether there was an expansion in the percent of patients in a physician's panel who had not previously been seen, as identified by a collection of procedure codes reserved for office visits with new, rather than established, patients.