Effect of Expanding Medicaid for Parents on Children’s Health Insurance Coverage

Abstract

IMPORTANCE In the United States, health insurance is not universal. Observational studies show an association between uninsured parents and children. This association persisted even after expansions in child-only public health insurance. Oregon’s randomized Medicaid expansion for adults, known as the Oregon Experiment, created a rare opportunity to assess causality between parent and child coverage. OBJECTIVE To estimate the effect on a child’s health insurance coverage status when (1) a parent randomly gains access to health insurance and (2) a parent obtains coverage. DESIGN, SETTING, AND PARTICIPANTS Oregon Experiment randomized natural experiment assessing the results of Oregon’s 2008 Medicaid expansion. We used generalized estimating equation models to examine the longitudinal effect of a parent randomly selected to apply for Medicaid on their child’s Medicaid or Children’s Health Insurance Program (CHIP) coverage (intent-to-treat analyses). We used per-protocol analyses to understand the impact on children’s coverage when a parent was randomly selected to apply for and obtained Medicaid. Participants included 14 409 children aged 2 to 18 years whose parents participated in the Oregon Experiment. EXPOSURES For intent-to-treat analyses, the date a parent was selected to apply for Medicaid was considered the date the child was exposed to the intervention. In per-protocol analyses, exposure was defined as whether a selected parent obtained Medicaid. MAIN OUTCOMES AND MEASURES Children’s Medicaid or CHIP coverage, assessed monthly and in 6-month intervals relative to their parent’s selection date. RESULTS In the immediate period after selection, children whose parents were selected to apply significantly increased from 3830 (61.4%) to 4152 (66.6%) compared with a nonsignificant change from 5049 (61.8%) to 5044 (61.7%) for children whose parents were not selected to apply. Children whose parents were randomly selected to apply for Medicaid had 18% higher odds of being covered in the first 6 months after parent’s selection compared with children whose parents were not selected (adjusted odds ratio [AOR] = 1.18; 95% CI, 1.10–1.27). The effect remained significant during months 7 to 12 (AOR = 1.11; 95% CI, 1.03–1.19); months 13 to 18 showed a positive but not significant effect (AOR = 1.07; 95% CI, 0.99–1.14). Children whose parents were selected and obtained coverage had more than double the odds of having coverage compared with children whose parents were not selected and did not gain coverage (AOR = 2.37; 95% CI, 2.14–2.64). CONCLUSIONS AND RELEVANCE Children’s odds of having Medicaid or CHIP coverage increased when their parents were randomly selected to apply for Medicaid. Children whose parents were selected and subsequently obtained coverage benefited most. This study demonstrates a causal link between parents’ access to Medicaid coverage and their children’s coverage.

The Effect of Parental Medicaid Expansions on Children's Health Insurance Coverage

“…We find that expansions in parental Medicaid have somewhat larger effects on eligible children's public coverage (possibly because of lower incomes among those becoming eligible for parental Medicaid). This is consistent with a "welcome-mat" effect suggested by Hudson and Moriya (2017) as well as the Oregon Medicaid Experiment findings (DeVoe et al 2015). However, we also find that increases in public coverage appear to crowd out some private coverage among some of the most persistently disadvantaged subgroups, perhaps suggesting a mechanism in which the parental Medicaid expansions affecting families with Medicaid/SCHIP eligible children disproportionately attracted privately insured children as their parents moved the entire family off an employer plan.…”

“…More recently, DeVoe et al () make use of the randomized selection of adults into Medicaid under the Oregon Health Insurance Experiment. They find that children of the treated adults saw their odds of Medicaid coverage more than double in the first 6 months.…”

The Role of Public Health Insurance in Reducing Child Poverty

“…16 In addition, there is significant evidence that predates the ACA that parental Medicaid coverage is an important determinant of whether eligible children enroll in coverage. 12,18–20 …”

Trends in Type of Health Insurance Coverage for US Children and Their Parents, 1998–2011

“…7-9 Previous research utilizing a natural experiment that randomized adults to coverage found a causal link between parent and child health insurance status. 10 Thus, it is important to consider trends in children's health insurance coverage in conjunction with trends affecting parents . Most past studies of health insurance focused on adults or children separately; those that considered both children and parents did not assess type of coverage.…”