Department of Epidemiology, University of Iowa College of Public Health, Iowa, Iowa, USA.
Community Dent Oral Epidemiol. 2024 Oct;52(5):708-715. doi: 10.1111/cdoe.12965. Epub 2024 Apr 28.
In the United States, adult dental benefits are optional in the state-managed, public insurance program, Medicaid. States also have the option to adapt their Medicaid program via waivers which pair healthy behaviour incentives (HBI) with cost-sharing. These waivers have proven ineffective, but the empirical evidence has ignored differences between states. This study aims to evaluate the impact of four state's HBI Medicaid waiver on dental visits among low-income adult population subject to incentives and cost-sharing requirements by the HBI waiver.
Analysing biannual data from the Behavioural Risk Factor Surveillance System's Oral Health module (2008-2018) with a Difference-in-Differences design, this study estimated the effect of a Healthy Behaviour Incentive waiver on the probability of visiting the dentist in the past year. The three states that implemented an HBI Waiver (Indiana, Michigan and Wisconsin) were analysed separately. Secondary outcomes included being uninsured and having all teeth extracted. Matrix Completion methods accounted for dynamic treatment and tested for non-common trends. Inference was based on randomization inference tests.
Only in Michigan was an HBI waiver consistently associated with a significant increase in the probability of a dental visit (Est. = 5.6%-points, p = .01). There was little convincing evidence that HBI waivers were associated with being uninsured or having all teeth extracted.
Between 2010 and 2019, many states have implemented an HBI waiver, each with a different approach to incentivizing dental visits. These implementation differences may explain the heterogeneous effects by state. More work is needed to evaluate how Medicaid waivers impact health outcomes in low-income populations.
在美国，由州政府管理的公共保险计划——医疗补助（Medicaid）中，成人牙科福利是可选的。各州还可以通过豁免来调整其医疗补助计划，将健康行为激励（HBI）与自付费用相结合。这些豁免已被证明是无效的，但实证证据忽略了各州之间的差异。本研究旨在评估四个州的 HBI 医疗补助豁免对接受 HBI 豁免的激励和自付费用要求的低收入成年人群体的牙科就诊次数的影响。
本研究采用双重差分设计，利用行为风险因素监测系统口腔健康模块（2008-2018 年）的两年期数据进行分析，估计健康行为激励豁免对过去一年看牙医概率的影响。分别分析了实施 HBI 豁免的三个州（印第安纳州、密歇根州和威斯康星州）。次要结果包括未参保和所有牙齿拔除。矩阵补全方法考虑了动态治疗，并测试了非共同趋势。基于随机化推断检验进行推断。
只有在密歇根州，HBI 豁免一直与看牙医概率的显著增加相关（估计值=5.6%，p=0.01）。几乎没有令人信服的证据表明 HBI 豁免与未参保或所有牙齿拔除有关。
2010 年至 2019 年间，许多州实施了 HBI 豁免，每个州都有不同的激励看牙医的方法。这些实施差异可能解释了各州之间的异质性影响。需要做更多的工作来评估医疗补助豁免如何影响低收入人群的健康结果。
