Responsible researcher: Bruno Benevit
Original title: Adult Medicaid benefit generosity and receipt of recommended health services among low-income children: The spillover effects of Medicaid adult dental coverage expansions
Author: Brandy J. Lipton
Intervention Location: United States
Sample Size: 17,274 children
Sector: Health Economics
Variable of Main Interest: Use of health services
Type of Intervention: Health insurance coverage
Methodology: DID, DDD, Event Study
Summary
Access to health services for children presents inequalities related to socioeconomic conditions. In this sense, public policies to expand health insurance coverage can minimize this situation. Medicaid coverage package on reducing disparities in medical needs resulting from income inequalities. The identified results revealed that, when taking advantage of changes in adult dental benefits at the state level over time, coverage is associated with increases of 14 and 5 percentage points, respectively, in the probability of a recent dental visit between parents and children directly exposed to politics. The effects on children appear to be concentrated in children under 12 years of age.
Access to health services for children presents inequalities related to socioeconomic conditions. Low-income children are considerably less likely to utilize health services compared to their high-income peers. Even for children insured by the Medicaid , which offers coverage for dental services in all states in the United States, this behavior continues even for children with low income, where this group is more likely to have dental problems and less likely to have dental appointments. (BERDAHL et al., 2016).
In addition to health impacts, reduced use of dental services can have negative effects on low-income children in other aspects of their lives, such as school attendance and academic performance (AGAKU et al., 2015). Thus, it is possible that a mechanism exists between the coverage of parents and their children, since health coverage involves a process of learning and internalizing the benefits of insurance throughout its use, in addition to considerations regarding its fixed costs. . Medicaid program's parental coverage package has the potential to positively impact the health of uninsured low-income children (LIPTON, 2021).
Medicaid been instrumental in expanding access to dental services among low-income adults and children in the United States. According to the National Health Interview Survey (NHIS), between 2000 and 2013, the rate of visits to the dentist among children from low-income families increased from 42% to 58%. However, even with this improvement, there was still a difference of 15 percentage points compared to children from higher-income families. This indicates that despite the preventive coverage provided by the program for children in all states, disparities in the use of dental care continued to exist. Additionally, children with public insurance had consistently lower dental visit rates than children with private insurance, with an 8 percentage point (pp) difference recorded in 2013.
These disparities reflect socioeconomic barriers to accessing dental care, even in populations covered by public insurance programs. Although Medicaid provided access to preventive services, low-income children, who face a higher risk of dental problems, continued to have less access to regular dental appointments. The increase in the use of dental services was more evident over time, but the difference in relation to children from families with greater purchasing power persisted. The inclusion of pediatric dental services as an essential benefit under the Affordable Care Act (ACA) has contributed to increased dental insurance coverage among children, yet inequities between socioeconomic groups have not been completely overcome.
State coverage programs for dental services in Medicaid varied greatly between 2000 and 2013. During that period, between 23 and 28 states offered some type of adult dental coverage beyond emergency services, while 17 states modified their policies. Approximately 61.6% of parents enrolled in the program had dental coverage during this period, but this percentage fell from 74.6% in 2000 to 44.2% in 2013 (LIPTON, 2021). For children, all states were required to provide full dental coverage through the Early and Periodic Screening, Diagnostic and Treatment (EPSDT) benefit, which included regular exams, fillings, and treatment of infections and pain. Children enrolled in the Children's Health Insurance Program (CHIP) in states with separate programs also had access to dental services needed to prevent illness and treat emergency conditions.
The study used data from the NHIS, a repeated cross-sectional survey representative of the non-institutionalized civilian population of the United States. Each family member responded to the survey, with one adult and one child per household providing more detailed information. Medicaid adult dental coverage policies between 2000 and 2013. The main outcome analyzed was whether the child had visited the dentist in the last six months, with the information being provided by one adult family member for children ages 1 to 17. The choice of this criterion was based on recommendations from the American Dental Association and the American Academy of Pediatric Dentistry . Additionally, the survey included questions about unmet dental care needs due to financial hardship.
The child sample consisted of 17,274 children between the ages of 1 and 17, with at least one coresident parent enrolled in Medicaid and with complete data on dental visits. Children from families who received Supplemental Social Security benefits in the previous year were excluded, as their parents were likely eligible for the program because of a disability. The majority of children (94%) were enrolled in Medicaid or CHIP, indicating more accessible eligibility rules for children. For the parent analysis, the sample included 12,167 adults ages 22 to 64 enrolled in Medicaid with at least one coresident child under age 18. Adults under the age of 22 were not considered in the sample, given that this group is eligible for dental coverage until age 20 through the Medicaid .
The Difference-in-Differences (DID) method was used to analyze the effects of changes in Medicaid over time, comparing states that changed these policies with those that did not change. The main premise of DID is that, in the absence of a change in policy, trends in outcomes in treated states would have paralleled those in control states. The model was established to control for fixed state characteristics and national trends that could simultaneously affect policies and outcomes. With this approach, the direct effects of adult tooth coverage policies after policy application were isolated by analyzing individuals over time.
Additionally, the event study method was used to investigate the evolution of the effects of changes in dental policies over time. The justification for this empirical strategy consists of capturing the variation when each state changed its coverage, measuring the effects of each period before and after implementation. This approach also allowed us to evaluate whether the hypothesis of parallel trends before the policy, fundamental to the validity of the DID method, is valid, in addition to also identifying how the effects developed for each period after its implementation.
As a robustness approach, the study presented intention-to-treat (ITT) estimation to overcome possible selection biases when analyzing the impact of changes in tooth coverage. Instead of focusing only on direct Medicaid , all low-income or low-education individuals were included in the analysis. The goal of this approach was to ensure that results reflected the average effect of the policy, regardless of actual participation in Medicaid , minimizing biases arising from changes in sample composition.
Finally, the impacts of the program were estimated using the Triple Difference method (DDD). Thus, an extra layer was added to the DID method by comparing differences in outcomes between treated and untreated groups within the same states. In this way, this modeling sought to control for temporal factors that could have influenced all state residents in similar ways, as well as identify indirect effects, such as the policy's impact on families that were not directly eligible for Medicaid , but could be influenced by parents. that conveyed information about dental care.
The main results using the DID method revealed that the introduction of dental benefits through the Medicaid resulted in a 13.8 pp increase in the probability that an adult had a dental visit in the last year, representing an increase of 27 % in relation to the average number of visits, which was 51.5%. When considering subgroups, the effect was more significant among women (15.4 pp) compared to men (8.2 pp). For parents with fewer children, the effects were also more evident. Among children, the increase varied between 3.8 and 5.1 pp in the probability of a consultation in the last six months, an increase of around 11% in relation to the control group. Considering other subgroups, higher increases were observed, especially when considering children aged 1 to 11 years (7.2 pp). Additionally, the analysis revealed that low-income families experienced a reduction in the need for emergency treatments and an increase in the use of preventive services, regardless of age or family composition. These results suggest that the policy not only increased access to dental care but also improved the overall quality of dental health among beneficiaries.
Regarding the intensive use of Medicaid , a significant increase was observed in the number of days that adults and children remained covered by the program. This increase in exposure time to the program favored more frequent access to dental services, resulting in a noticeable improvement in oral health visits. For children, the data indicated that those with a greater number of years on Medicaid had more regular visits to the dentist, suggesting a positive effect of continuous coverage.
Using the event study method, a cumulative impact behavior of the policy on visits to dentists for both adults and children was identified. In the year the policy was implemented, there was a 4.6 pp reduction in parents' dental visits, indicating an initial adaptation. However, in subsequent years, there was a decline of 9.6 pp to 14.0 pp in visits. Among children, the effects were smaller initially, with a reduction of 3.1 pp, but increased to 6.4 pp two years after the policy change.
The results using the DDD method reinforced the evidence previously identified. When incorporating an intrastate control group, the observed parent effects remained significant, although slightly smaller compared to those estimated by DID. Among children, the impact was also maintained, with a slight reduction observed when using a low-income control group.
In this article, the authors investigated the impact of Medicaid on the dental health of insured families. Results showed that the program's expansion significantly increased access to dental care, resulting in an improvement in oral health among beneficiaries. The analysis also revealed that children from low-income families experienced a reduction in the need for emergency treatments and an increase in the use of preventive services, regardless of age or family composition.
The evidence from this study offers relevant support for understanding the effects of Medicaid on dental health, informing public policy makers about the intra-family spillover effects of the program, especially for families in situations of socioeconomic vulnerability. Furthermore, they highlight the potential of policies that prioritize preventive care and the importance of ensuring continuity of coverage, aiming to improve the population's health and reduce the costs associated with emergency care.
References
AGAKU, IT et al. Association between unmet dental needs and school absenteeism because of illness or injury among US school children and adolescents aged 6–17 years, 2011–2012. Preventive Medicine , vol. 72, p. 83–88, mar. 2015.
BERDAHL, T. et al. Annual Report on Children's Health Care: Dental and Orthodontic Utilization and Expenditures for Children, 2010–2012. Academic Pediatrics , vol. 16, no. 4, p. 314–326, May 2016.
LIPTON, BJ Adult Medicaid benefit generosity and receipt of recommended health services among low-income children: The spillover effects of Medicaid adult dental coverage expansions. Journal of Health Economics , 2021.
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