Research
Working papers
How should payers balance fiscal sustainability with access to transformative medical technology? We study Louisiana’s 2019 Medicaid subscription model for hepatitis C (HCV), the first example of a U.S. state employing a two-part tariff to secure unlimited access to curative medicines. Using a differences-in-differences design comparing spending on beneficiaries with HCV to those with diabetes or HIV, we find that treatment volume tripled, medical spending fell, and new HCV diagnoses declined 23 percent. The state’s $37 million in incremental spending on antivirals generated $266 million in five-year savings. Innovative financing models can generate health benefits and near-term savings for payers.
We use a five percent sample of Americans’ credit bureau data, combined with a regression discontinuity approach, to estimate the effect of universal health insurance at age 65—when most Americans become eligible for Medicare—at the national, state, and local level. We find a 30 percent reduction in debt collections—and a two-thirds reduction in the geographic variation in collections—with limited effects on other financial outcomes. The areas that experienced larger reductions in collections debt at age 65 were concentrated in the Southern United States, and had higher shares of black residents, people with disabilities, and for-profit hospitals.
Publications
Economics
Medicaid is one of the largest public programs in the United States—providing health insurance to over 75 million low-income Americans—and over three quarters of its enrollees receive care via private “managed care” insurers. In this article, we make three central points about the economics of contracting out Medicaid to private insurers. First, the empirical evidence on Medicaid privatization is mixed: contracting out has not meaningfully reduced public costs or improved quality of care. Second, we propose a framework, which we call “procured competition,” to describe the unique structure of Medicaid managed care as a hybrid of public procurement and regulated competition. Third, we discuss the key policy levers across procurement, competition, and consumer choice in this model. Throughout, we highlight open research questions, arguing that the enormous variation in how states design these programs—combined with limited evidence on what works—represents a promising area for high-impact scholarship.
This paper examines the effects of privatizing social health insurance. We exploit a natural experiment in Medicaid, wherein nearly 100,000 enrollees were randomly assigned between a publicly operated fee-for-service system and private managed care. Managed care reduced costs by 5.6 percent via cost-effective substitutions among prescription drugs and via lower prices for outpatient services. We present evidence that pharmacy utilization management was the key mechanism reducing overuse and encouraging substitution to lower-cost drugs without decreasing observed quality. In contrast, privatizing medical benefits led to only modest savings and was associated with decreased health care quality and consumer satisfaction. (JEL G22, H41, I13, I18, I38)
Health plans for the poor increasingly limit access to specialty hospitals. We investigate the role of adverse selection in generating this equilibrium among private plans in Medicaid. Studying a network change, we find that covering a top cancer hospital causes severe adverse selection, increasing demand for a plan by 50% among enrollees with cancer versus no impact for others. Medicaid’s fixed insurer payments make offsetting this selection, and the contract distortions it induces, challenging, requiring either infeasibly high payment rates or near-perfect risk adjustment. By contrast, a small explicit bonus for covering the hospital is sufficient to make coverage profitable.
Leveraging the random assignment of over 50,000 Medicaid enrollees in New York, I present causal evidence that narrower networks are a blunt instrument for reducing health care spending. While narrower networks constrain spending, they do so by generating hassle costs that reduce quantity, with modest effects on prices paid to providers. Enrollees assigned to narrower networks use fewer of both needed and unneeded services and are less satisfied with their plans. Using my causal estimates to construct counterfactuals, I identify an alternative assignment policy that reduces spending without harming satisfaction by matching consumers with narrower networks that include their providers. (JEL H51, H75, I13, I18, I38)
Exploiting the random assignment of Medicaid beneficiaries to managed care plans, we find substantial plan-specific spending effects despite plans having identical cost sharing. Enrollment in the lowest-spending plan reduces spending by at least 25%-primarily through quantity reductions-relative to enrollment in the highest-spending plan. Rather than reducing “wasteful” spending, lower-spending plans broadly reduce medical service provision-including the provision of low-cost, high-value care-and worsen beneficiary satisfaction and health. Consumer demand follows spending: a 10 percent increase in plan-specific spending is associated with a 40 percent increase in market share. These facts have implications for the government’s contracting problem and program cost growth.
We propose a method for reporting how program evaluations reduce gaps between groups, such as the gender or Black-White gap. We first show that the reduction in disparities between groups can be written as the difference in conditional average treatment effects (CATE) for each group. Then, using a Kitagawa-Oaxaca-Blinder-style decomposition, we highlight how these CATE can be decomposed into unexplained differences in CATE in other observables versus differences in composition across other observables (e.g. the “endowment”). Finally, we apply this approach to study the impact of Medicare on American’s access to health insurance.
Health policy
2026
Despite the importance of primary care in disease prevention, few studies have examined behavioral interventions to increase primary care engagement. In partnership with the Maine Department of Health and Human Services, we implemented a randomized mail-based outreach strategy to connect newly enrolled adults in MaineCare Primary Care Case Management with primary care providers. From March 16, 2021, through January 1, 2022, members were randomized to receive either (1) a standard text-heavy outreach packet (control arm) or (2) the standard packet plus 2 visually simplified mailers that emphasized the value and low cost of a primary care check-up and listed a single primary care provider near the enrollee’s home (intervention arm). We found that over 12 months of follow-up, the intervention had no significant effects on the rate or number of primary care visits, emergency department visits, or inpatient hospitalizations. We also observed no significant impact on Medicaid enrollment or recommended primary care services, including receipt of flu shots, cholesterol screenings, or mammograms. Results suggest that barriers targeted by the mailers were not primary drivers of primary care engagement, and other strategies are needed to help connect new Medicaid enrollees with primary care.
Importance Adult dental coverage under Medicaid varies widely across states and delivery systems. Most adult beneficiaries are now enrolled in managed care, yet little is known about how these benefits are structured and implemented within Medicaid managed care organizations (MCOs). Objective To examine trends in the generosity, delivery models, and enrollment patterns of adult dental benefits delivered through Medicaid MCOs and assess coverage alignment with Medicaid fee-for-service (FFS) coverage. Design, Setting, and Participants This cross-sectional analysis included adult Medicaid beneficiaries aged 19 years or older who had state Medicaid MCO or FFS coverage across all 50 states and Washington, DC. This analysis used a novel linked national dataset combining multiple Centers for Medicare & Medicaid Services administrative sources from 2016 to 2022. The analysis was conducted from April 8, 2025, to October 8, 2025. Exposures State-level Medicaid MCO or FFS program with adult comprehensive dental coverage, emergency-only dental coverage, or no dental coverage. Main Outcomes and Measures The generosity of dental benefits; the degree of alignment in benefit generosity between Medicaid MCO and Medicaid FFS programs; and enrollment of adults in dental MCO or FFS programs by benefit (coverage) type. Results The number of states offering comprehensive adult dental benefits through Medicaid MCOs increased from 33 (64.7%) in 2016 to 36 (70.6%) in 2022. Carve-out models, typically using stand-alone prepaid health plans for dental coverage, increased from 4 states (7.8%) in 2016 to 8 states (15.7%) in 2022. In 2016, 51.0% of states had mismatched benefit levels between MCO and FFS programs compared with 35.3% in 2022. The number of MCO enrollees with comprehensive dental coverage increased from 14.2 million (58.7%) in 2016 to 25.3 million (59.8%) in 2022, reflecting substantial managed care penetration. Conclusions and Relevance This study found that although the generosity and scope of MCO dental benefits expanded over time, alignment with FFS programs remained inconsistent. As new legislation cuts federal funding to states, understanding how dental benefits are designed and delivered is critical to inform future coverage decisions and ensure equitable access.
2025
Objective: To study the impact of managed long-term services and supports (MLTSS) on the use of long-term care, as well as acute care. Study Setting And Design: We use a staggered difference-in-differences (DiDs) regression design, exploiting the variation in timing of the rollout of MLTSS programs across states between 2004 and 2018. We compared individuals in states that implemented MLTSS with individuals in states that did not implement MLTSS. Our outcomes included formal home care use, nursing home status, informal care use, hospitalizations, overnight nursing home visits, and falls. Data Source And Analytic Sample: This study uses secondary data from the Health and Retirement Study data, linked with state identifiers. The sample includes adults aged 65 and older who report at least one functional limitation. Principal Findings: The shift to MLTSS leads to a 2.5 percentage point (pp) increase (95% CI: 0.8 pp, 4.3 pp) in home care users, a 3-percentage point decrease (95% CI: -5.38 pp, -0.25 pp) in informal care users, and no statistically significant change in nursing home occupancy or health outcomes. We also find suggestive evidence of reductions in the number of home care individuals living in MLTSS states receive, with a 7.02-h (95% CI: -12.96, -1.07), or nearly 27% decrease, in monthly formal care received by this population. Conclusion: These findings suggest that MLTSS increased the share of home and community-based services (HCBS) users but restricted the amount of HCBS used per beneficiary, with ambiguity around whether this occurred at the expense of beneficiaries.
This case-control study evaluates the impact of a hospitalization on credit scores for Medicaid beneficiaries in Louisiana stratified by sex, race, and ethnicity.
Importance: There is increased interest in public reporting of, and linking financial incentives to, the performance of organizations on health equity metrics, but variation across organizations could reflect differences in performance or selection bias. Objective: To assess whether differences across health plans in sex- and age-adjusted racial disparities are associated with performance or selection bias. Design, Setting, And Participants: This cross-sectional study leveraged a natural experiment, wherein a southern US state randomly assigned much of its Medicaid population to 1 of 5 plans after shifting to managed care in 2012. Enrollee-level administrative claims and enrollment data from 2011 to 2015 were obtained for self-identified Black and White enrollees. The analyses were limited to Black and White Medicaid enrollees because they accounted for the largest percentages of the population and could be compared with greater statistical power than other groups. Data were analyzed from June 2021 to September 2024. Exposures: Plan enrollment via self-selection (observational population) vs random assignment (randomized population). Main Outcomes And Measures: Annual counts of primary care visits, low-acuity emergency department visits, prescription drug fills, and total spending. For observational and randomized populations, models of each outcome were fit as a function of plan indicators, indicators for race, interactions between plan indicators and race, and age and sex. Models estimated the magnitude of racial differences within each plan and tested whether this magnitude varied across plans. Results: Of 118 101 enrollees (mean [SD] age, 9.3 [7.5] years; 53.0% female; 61.4% non-Hispanic Black; and 38.6% non-Hispanic White), 70.2% were included in the randomized population, and 29.8% were included in the observational population. Within-plan differences in primary care visits, low-acuity emergency department visits, prescription drug use, and total spending between Black and White enrollees were large but did not vary substantially and were not statistically significantly different across plans in the randomized population, suggesting minimal effects of plans on racial differences in these measures. In contrast, in the observational population, racial differences varied substantially across plans (standard deviations 2-3 times greater than in the randomized population); this variation was statistically significant after adjustment for multiple testing, except for emergency department visits. Greater between-plan variation in racial differences in the observational population was only partially explained by sampling error. Stratifying by race did not bring observational estimates of plan effects meaningfully closer to randomized estimates. Conclusions And Relevance: This cross-sectional study showed that selection bias may mischaracterize plans’ relative performance on measures of health care disparities. It is critical to address disparities in Medicaid, but adjusting plan payments based on disparity measures may have unintended consequences.
Importance Work requirements are a controversial feature of US safety-net programs, with some policymakers seeking to expand their use. Little is known about the demographic, clinical, and socioeconomic characteristics of individuals most likely to be negatively impacted by work requirements. Objective To examine the association between work requirements and safety-net program enrollment. Design, Setting, and Participants This cohort study included Medicaid and Supplemental Nutrition Assistance Program (SNAP) enrollees in Connecticut. The impact of SNAP work requirements for able-bodied adults without dependents—the target population—was estimated using a triple-differences research design comparing outcomes before and after the policy (first difference) in affected and exempted towns (second difference) between the targeted population and untargeted parents and caregivers (third difference). SNAP and Medicaid enrollment trends were assessed for a 24-month period, and the characteristics of individuals most likely to lose coverage were examined. Data were collected from August 2015 to April 2018, and data were analyzed from August 2022 to September 2024. Exposures The reintroduction of SNAP work requirements in 2016. Main Outcomes and Measures Proportion of enrollees disenrolled from SNAP and Medicaid. Results Of 81 888 Medicaid enrollees in Connecticut, 46 872 (57.2%) were female, and the mean (SD) age was 36.6 (7.0) years. Of these, 38 344 were able-bodied adults without dependents, of which 19 172 were exposed to SNAP work requirements, and 43 544 were parents or caregivers exempted from SNAP work requirements. SNAP coverage declined 5.9 percentage points (95% CI, 5.1-6.7), or 25%, following work requirements. There were no statistically significant changes in Medicaid coverage (0.2 percentage points; 95% CI, −1.4 to 1.0). Work requirements disproportionately affected individuals with more chronic illnesses, targeted beneficiaries who were older, and beneficiaries with lower incomes. Individuals with diabetes were 5 percentage points (95% CI, 0.8-9.3), or 91%, likelier to lose SNAP coverage than those with no chronic conditions; older SNAP beneficiaries (aged 40 to 49 years) with multiple comorbidities were 7.3 percentage points (95% CI, 4.3-11.3), or 553%, likelier to disenroll than younger beneficiaries (aged 25 to 29 years) without chronic conditions; and households with the lowest incomes were 18.6 percentage points (95% CI, 11.8-25.4), or 204%, likelier to lose coverage than the highest income SNAP beneficiaries. Conclusions and Relevance In this cohort study, SNAP work requirements led to substantial reductions in SNAP coverage, especially for the most clinically and socioeconomically vulnerable. Work requirements had little effect on Medicaid coverage, suggesting they did not lead to sufficient increases in employment to transition beneficiaries off the broader safety net.
2024
The Affordable Care Act Marketplaces may improve access to dental insurance, but little is known about the availability of such coverage. We used data from state and federal Marketplace sources to describe the availability of adult dental plans, including Stand-alone Dental Plans and those embedded in medical plans. We also examined the characteristics of counties with limited dental insurer participation and those that experienced a net loss of Stand-alone Dental Plan insurers between 2016 and 2023. We found that in 2023, at least one Stand-alone Dental Plan was offered in every state, and thirty-six states offered embedded dental plans. Most counties (63.6 percent) had access to more than five insurers offering adult dental plans, whereas approximately 4 percent had only one insurer offering adult dental plans. Counties in state-based Marketplaces, rural areas, and dentist shortage areas were more likely to be counties with limited dental insurer participation. The net loss of Stand-alone Dental Plans between 2016 and 2023 was more common in state-based Marketplaces and disadvantaged counties. Our findings can inform future policies to improve the dental insurance Marketplace and access to affordable dental care.
Importance: Medicare provides nearly universal insurance coverage at age 65 years. However, how Medicare eligibility affects disparities in health insurance coverage, access to care, and health status among individuals by sexual orientation and gender identity is poorly understood. Objective: To assess the association of Medicare eligibility with disparities in health insurance coverage, access to care, and self-reported health status among individuals by sexual orientation and by gender identity. Design, Setting, And Participants: This cross-sectional study used the age discontinuity for Medicare eligibility at age 65 years to isolate the association of Medicare with health insurance coverage, access to care, and self-reported health status, by their sexual orientation and by their gender identity. Data were collected from the Behavioral Risk Factor Surveillance System for respondents from 51 to 79 years old from 2014 to 2021. Data analysis was performed from September 2022 to April 2023. Exposures: Medicare eligibility at age 65 years. Main Outcomes And Measures: Proportions of respondents with health insurance coverage, usual source of care, cost barriers to care, influenza vaccination, and self-reported health status. Results: The study population included 927 952 individuals (mean [SD] age, 64.4 [7.7] years; 524 972 [56.6%] females and 402 670 [43.4%] males), of whom 28 077 (3.03%) identified as a sexual minority-lesbian, gay, bisexual, or another sexual minority identity (LGB+) and 3286 (0.35%) as transgender or gender diverse. Respondents who identified as heterosexual had greater improvements at age 65 years in insurance coverage (4.2 percentage points [pp]; 95% CI, 4.0-4.4 pp) than those who identified as LGB+ (3.6 pp; 95% CI, 2.3-4.8 pp), except when the analysis was limited to a subsample of married respondents. For access to care, improvements in usual source of care, cost barriers to care, and influenza vaccination were larger at age 65 years for heterosexual respondents compared with LGB+ respondents, although confidence intervals were overlapping and less precise for LGB+ individuals. For self-reported health status, the analyses found larger improvements at age 65 years for LGB+ respondents compared with heterosexual respondents. There was considerable heterogeneity by state in disparities by sexual orientation among individuals who were nearly eligible for Medicare (close to 65 years old), with the US South and Central states demonstrating the highest disparities. Among the top-10 highest-disparities states, Medicare eligibility was associated with greater increases in coverage (6.7 pp vs 5.0 pp) and access to a usual source of care (1.4 pp vs 0.6 pp) for LGB+ respondents compared with heterosexual respondents. Conclusions And Relevance: The findings of this cross-sectional study indicate that Medicare eligibility was not associated with consistently greater improvements in health insurance coverage and access to care among LGBTQI+ individuals compared with heterosexual and/or cisgender individuals. However, among sexual minority individuals, Medicare may be associated with closing gaps in self-reported health status, and among states with the highest disparities, it may improve health insurance coverage, access to care, and self-reported health status.
This cross-sectional study compares average credit scores and unpaid medical and nonmedical debts in collections among Black, Hispanic, and White adults with Medicaid coverage.
Importance: Several state Medicaid agencies have transitioned from traditional fee-for-service to a value-centric alternative payment model (APM) to reimburse federally qualified health centers (FQHCs). Little is known about the effects of this shift on FQHC performance. Objective: To assess the association between APMs and the clinical performance, payer mix, risk profile, and financial sustainability of FQHCs. Design, Setting, And Participants: This retrospective cohort study was performed in 684 FQHCs (representing 37 states plus the District of Columbia) that continuously operated between January 2009 and December 2021. Data on payer mix (eg, type of insurance) and risk profile (eg, proportion of patients with chronic conditions) of FQHC patients were obtained from the Uniform Data System, and clinic-level financial data (eg, revenue) were obtained from Internal Revenue Service form 990 tax documents. Data were analyzed between November 2022 and October 2023. Exposure: Initial rollout of a value-based payment model (ie, an APM) for FQHCs, as offered by state Medicaid program, between January 2013 and December 2021. Main Outcomes And Measures: The main outcomes were 4 audited process measures of health care quality (cervical and colorectal cancer screening and body mass index [BMI] assessment for adults and children) and 2 intermediate health outcome measures (hypertension control and diabetes control). A difference-in-differences design was used with staggered implementation comparing FQHCs before and after the initial APM rollout vs contemporaneous changes in FQHCs in states without APMs. Results: A total of 684 FQHCs (8892 FQHC-years) that served 17 823 959 patients in 2021 (57.3% female) were included in the study. Among FQHCs in states implementing APMs, significant differential increases in 3 of the 4 process quality measures were observed compared with FQHCs in states that did not implement an APM: colorectal cancer screening (3.24 percentage points [pp]; 95% CI, 1.40-5.08 pp), adult BMI (3.19 pp; 95% CI, 0.70-5.68 pp), and child BMI (4.50 pp; 95% CI, 1.83-7.17 pp). There were also modest differential improvements in blood pressure control for individuals with hypertension (1.02 pp; 95% CI, 0.04-2.00 pp) and blood glucose control for individuals with type 2 diabetes (1.02 pp; 95% CI, 0.02-2.02 pp) compared with FQHCs in states without an APM. There was no evidence that the APM rollout was associated with clinics selecting healthier patients (-0.01 pp; 95% CI, -0.21 to 0.19 pp) or stinting on care (-0.02 visits; 95% CI, -0.08 to 0.04 visits). Conclusions And Relevance: In this cohort study, introduction of Medicaid APM options for FQHCs was associated with modest, statistically significant increases in quality concentrated among FQHCs with APM models that explicitly incentivized quality. This finding suggests that APMs can be both a financially viable and a health-promoting model for reimbursement in the health care safety net.
2023
Since 1965, the US federal government has incentivized physicians to practice in high-need areas of the country through the designation of Health Professional Shortage Areas (HPSAs). Despite its being in place for more than half a century and directing more than a billion dollars annually, there is limited evidence of the HPSA program’s effectiveness at reducing geographic disparities in access to care and health outcomes. Using a generalized difference-in-differences design with matching, we found no statistically significant changes in mortality or physician density from 1970 to 2018 after a county-level HPSA designation. As a result, we found that 73 percent of counties designated as HPSAs remained physician shortage areas for at least ten years after their inclusion in the program. Fundamental improvements to the program’s design and incentive structure may be necessary for it to achieve its intended results.
Objective: To determine whether health systems in the United States modify treatment or discharge decisions for otherwise similar patients based on health insurance coverage. Design: Regression discontinuity approach. Setting: American College of Surgeons’ National Trauma Data Bank, 2007-17. Participants: Adults aged between 50 and 79 years with a total of 1 586 577 trauma encounters at level I and level II trauma centers in the US. Interventions: Eligibility for Medicare at age 65 years. Main Outcome Measures: The main outcome measure was change in health insurance coverage, complications, in-hospital mortality, processes of care in the trauma bay, treatment patterns during hospital admission, and discharge locations at age 65 years. Results: 1 586 577 trauma encounters were included. At age 65, a discontinuous increase of 9.6 percentage points (95% confidence interval 9.1 to 10.1) was observed in the share of patients with health insurance coverage through Medicare at age 65 years. Entry to Medicare at age 65 was also associated with a decrease in length of hospital stay for each encounter, of 0.33 days (95% confidence interval -0.42 to -0.24 days), or nearly 5%), which coincided with an increase in discharges to nursing homes (1.56 percentage points, 95% confidence interval 0.94 to 2.16 percentage points) and transfers to other inpatient facilities (0.57 percentage points, 0.33 to 0.80 percentage points), and a large decrease in discharges to home (1.99 percentage points, -2.73 to -1.27 percentage points). Relatively small (or no) changes were observed in treatment patterns during the patients’ hospital admission, including no changes in potentially life saving treatments (eg, blood transfusions) or mortality. Conclusions: The findings suggest that differences in treatment for otherwise similar patients with trauma with different forms of insurance coverage arose during the discharge planning process, with little evidence that health systems modified treatment decisions based on patients’ coverage.
Importance: There is evidence that Republican-leaning counties have had higher COVID-19 death rates than Democratic-leaning counties and similar evidence of an association between political party affiliation and attitudes regarding COVID-19 vaccination; further data on these rates may be useful. Objective: To assess political party affiliation and mortality rates for individuals during the initial 22 months of the COVID-19 pandemic. Design, Setting, And Participants: A cross-sectional comparison of excess mortality between registered Republican and Democratic voters between March 2020 and December 2021 adjusted for age and state of voter registration was conducted. Voter and mortality data from Florida and Ohio in 2017 linked to mortality records for January 1, 2018, to December 31, 2021, were used in data analysis. Exposures: Political party affiliation. Main Outcomes And Measures: Excess weekly deaths during the COVID-19 pandemic adjusted for age, county, party affiliation, and seasonality. Results: Between January 1, 2018, and December 31, 2021, there were 538 159 individuals in Ohio and Florida who died at age 25 years or older in the study sample. The median age at death was 78 years (IQR, 71-89 years). Overall, the excess death rate for Republican voters was 2.8 percentage points, or 15%, higher than the excess death rate for Democratic voters (95% prediction interval [PI], 1.6-3.7 percentage points). After May 1, 2021, when vaccines were available to all adults, the excess death rate gap between Republican and Democratic voters widened from -0.9 percentage point (95% PI, -2.5 to 0.3 percentage points) to 7.7 percentage points (95% PI, 6.0-9.3 percentage points) in the adjusted analysis; the excess death rate among Republican voters was 43% higher than the excess death rate among Democratic voters. The gap in excess death rates between Republican and Democratic voters was larger in counties with lower vaccination rates and was primarily noted in voters residing in Ohio. Conclusions And Relevance: In this cross-sectional study, an association was observed between political party affiliation and excess deaths in Ohio and Florida after COVID-19 vaccines were available to all adults. These findings suggest that differences in vaccination attitudes and reported uptake between Republican and Democratic voters may have been factors in the severity and trajectory of the pandemic in the US.
Washington Post 1 2 3 · New York Times 1 2 · Financial Times · NBC News · Slate · The Intercept
While much of the causal inference literature has focused on addressing internal validity biases, both internal and external validity are necessary for unbiased estimates in a target population of interest. However, few generalizability approaches exist for estimating causal quantities in a target population that is not well-represented by a randomized study but is reflected when additionally incorporating observational data. To generalize to a target population represented by a union of these data, we propose a novel class of conditional cross-design synthesis estimators that combine randomized and observational data, while addressing their estimates’ respective biases-lack of overlap and unmeasured confounding. These methods enable estimating the causal effect of managed care plans on health care spending among Medicaid beneficiaries in New York City, which requires obtaining estimates for the 7% of beneficiaries randomized to a plan and 93% who choose a plan, who do not resemble randomized beneficiaries. Our new estimators include outcome regression, propensity weighting, and double robust approaches. All use the covariate overlap between the randomized and observational data to remove potential unmeasured confounding bias. Applying these methods, we find substantial heterogeneity in spending effects across managed care plans. This has major implications for our understanding of Medicaid, where this heterogeneity has previously been hidden. Additionally, we demonstrate that unmeasured confounding rather than lack of overlap poses a larger concern in this setting.
This cross-sectional study assesses the prevalence and magnitude of state-level delivery event–triggered kick payments to Medicaid managed care plans and their association with delivery costs.
The objective of risk adjustment is not to predict spending accurately but to support the social goals of a payment system, which include equity. Setting population-based payments at accurate predictions risks entrenching spending levels that are insufficient to mitigate the impact of social determinants on health care use and effectiveness. Instead, to advance equity, payments must be set above current levels of spending for historically disadvantaged groups. In analyses intended to guide such reallocations, we found that current risk adjustment for the community-dwelling Medicare population overpredicts annual spending for Black and Hispanic beneficiaries by $376-$1,264. The risk-adjusted spending for these populations is lower than spending for White beneficiaries despite the former populations’ worse risk-adjusted health and functional status. Thus, continued movement from fee-for-service to population-based payment models that omit race and ethnicity from risk adjustment (as current models do) should result in sizable resource reallocations and incentives that support efforts to address racial and ethnic disparities in care. We found smaller overpredictions for less-educated beneficiaries and communities with higher proportions of residents who are Black, Hispanic, or less educated, suggesting that additional payment adjustments that depart from predictive accuracy are needed to support health equity. These findings also suggest that adding social risk factors as predictors to spending models used for risk adjustment may be counterproductive or accomplish little.
Background: Medicaid, the primary source of insurance coverage for disadvantaged Americans, was originally designed as a temporary safety-net program. No studies have used long-run data to assess the recent use of the program by beneficiaries. Objective: To assess patterns of short- and long-term enrollment among beneficiaries, using a 10-year longitudinal panel of Michigan Medicaid eligibility data. Design: Primary analyses assessing trends in Medicaid enrollment among cohorts of existing and new beneficiaries. Setting: Administrative records from Michigan Medicaid for the period 2011 to 2020. Participants: 3.97 million Medicaid beneficiaries. Measurements: Short- and long-term enrollment in the program. Results: The sample includes 3.97 million unique beneficiaries enrolled at some point between 2011 and 2020. Among a cohort of 1.23 million beneficiaries enrolled in 2011, over half (53%) were also enrolled in Medicaid in June 2020, spending, on average, two-thirds of that period (67%) on Medicaid. These beneficiaries, however, experienced substantial lapses in coverage, as only 25% were continuously enrolled throughout the period. Enrollment was less stable when assessed from the perspective of newly enrolled beneficiaries, of whom only 37% remained enrolled at the end of the study period. Limitation: Primary estimates from a single state. Conclusion: For many beneficiaries, Medicaid has served as their primary source of coverage for at least a decade. This pattern would justify increasing investments in the program to improve long-term health outcomes. Primary Funding Source: Self-funded.
2022
Objective: The aim was to assess the magnitude of health care disparities in treatment for substance use disorder (SUD) and the role of health plan membership and place of residence in observed disparities in Medicaid Managed Care (MMC) plans in New York City (NYC). Data Source: Medicaid claims and managed care plan enrollment files for 2015-2017 in NYC. Research Design: We studied Medicaid enrollees with a SUD diagnosis during their first 6 months of enrollment in a managed care plan in 2015-2017. A series of linear regression models quantified service disparities across race/ethnicity for 5 outcome indicators: treatment engagement, receipt of psychosocial treatment, follow-up after withdrawal, rapid readmission, and treatment continuation. We assessed the degree to which plan membership and place of residence contributed to observed disparities. Results: We found disparities in access to treatment but the magnitude of the disparities in most cases was small. Plan membership and geography of residence explained little of the observed disparities. One exception is geography of residence among Asian Americans, which appears to mediate disparities for 2 of our 5 outcome measures. Conclusions: Reallocating enrollees among MMC plans in NYC or evolving trends in group place of residence are unlikely to reduce disparities in treatment for SUD. System-wide reforms are needed to mitigate disparities.
Importance Medicaid insures a disproportionate share of adults with substance use disorder (SUD) and is thus uniquely positioned to facilitate access to care. Many enrollees receive coverage through Medicaid managed care (MMC) plans, which receive capitated payments in exchange for coverage of a defined set of benefits. Historically, coverage of substance use services has been carved out of MMC plans and financed fee-for-service (FFS) by state Medicaid programs, but in recent years, many states have opted to carve in this benefit. Little is known about whether MMC coverage of substance use services, relative to FFS coverage, is associated with changes in utilization. Objective To examine the association between changes in MMC coverage of substance use services and admissions for substance use treatment. Design, Setting, and Participants This cross-sectional study examined changes in admissions for substance use treatment in 2 states after coverage of substance use services was either carved into (Nebraska) or carved out of (Maryland) comprehensive MMC coverage. Synthetic control methods were used to compare changes in admissions between states that did and did not alter MMC coverage of substance use services. Data on substance use treatment admissions were obtained from the Treatment Episode Data Set—Admissions from 2010 to 2019. Exposures Carve-outs or carve-ins of coverage for both inpatient and outpatient substance use services from comprehensive MMC coverage. Main Outcomes and Measures Reported substance use treatment admissions per 100 000 residents and admissions by treatment type (ie, rehabilitation or residential, outpatient, and detoxification) per 100 000 residents. Results Maryland’s carve-out was associated with an additional mean 787.1 (95% CI, 624.6-1141.7) substance use admissions per 100 000 residents during 2015 and 2016, a relative increase of 104.4% (95% CI, 64.4%-154.1%) compared with its synthetic control. This increase was concentrated among changes in outpatient services utilization. In Nebraska, the carve-in was associated with a mean decrease of 97.2 (95% CI, −23.4 to 213.6) admissions per 100 000 residents, a relative decrease of 33.2% (95% CI, −54.1% to 29.6%) compared with its synthetic control and was concentrated primarily among admissions for detoxification services. Conclusions and Relevance The results of this cross-sectional study suggest that carving out coverage of substance use services and financing them through FFS coverage may be associated with overall increases in treatment utilization but with heterogeneous associations across states and treatment types.
Importance: There is limited evaluation of the performance of Medicaid managed care (MMC) private plans in covering substance use disorder (SUD) treatment. Objective: To compare the performance of MMC plans across 19 indicators of access, quality, and outcomes of SUD treatment. Design Setting And Participants: This cross-sectional study used administrative claims and mandatory assignment to plans of up to 159 016 adult Medicaid recipients residing in 1 of the 5 counties (boroughs) of New York, New York, from January 2009 to December 2017 to identify differences in SUD treatment access, patterns, and outcomes among different types of MMC plans. Data from the latest years were received from the New York State Department of Health in October 2019, and analysis began soon thereafter. Approximately 17% did not make an active choice of plan, and a subset of these (approximately 4%) can be regarded as randomly assigned. Exposures: Plan assignment. Main Outcomes And Measures: Percentage of the enrollees achieving performance measures across 19 indicators of access, process, and outcomes of SUD treatment. Results: Medicaid claims data from 159 016 adults (mean [SD] age, 35.9 [12.7] years; 74 261 women [46.7%]; 8746 [5.5%] Asian, 73 783 [46.4%] Black, and 40 549 [25.5%] White individuals) who were auto assigned to an MMC plan were analyzed. Consistent with national patterns, all plans achieved less than 50% (range, 0%-62.1%) on most performance measures. Across all plans, there were low levels of treatment engagement for alcohol (range, 0%-0.4%) and tobacco treatment (range, 0.8%-7.2%), except for engagement for opioid disorder treatment (range, 41.5%-61.4%). For access measures, 4 of the 9 plans performed significantly higher than the mean on recognition of an SUD diagnosis, any service use for the first time, and tobacco use screening. Of the process measures, total monthly expenditures on SUD treatment was the only measure for which plans differed significantly from the mean. Outcome measures differed little across plans. Conclusions And Relevance: The results of this cross-sectional study suggest the need for progress in engaging patients in SUD treatment and improvement in the low performance of SUD care and limited variation in MMC plans in New York, New York. Improvement in the overall performance of SUD treatment in Medicaid potentially depends on general program improvements, not moving recipients among plans.
Importance: Administrative records indicate that more than half of the 80 million Medicaid enrollees identify as belonging to a racial and ethnic minority group. Despite this, disparities within the Medicaid program remain understudied. For example, we know of no studies examining racial differences in Medicaid spending, a potential measure of how equitably state resources are allocated. Objectives: To examine whether and to what extent there are differences in health care spending and utilization between Black and White enrollees in Medicaid. Design Setting And Participants: This cross-sectional study used calendar year 2016 administrative data from 3 state Medicaid programs and included 1 966 689 Black and White Medicaid enrollees. Analyses were performed between January 28, 2021, and October 18, 2021. Exposures: Self-reported race. Main Outcomes And Measures: Rates and racial differences in health care spending and utilization (including Healthcare Effectiveness Data and Information Set [HEDIS] access measures). Results: Of 1 966 689 Medicaid adults and children (mean [SD] age, 20.3 [17.1] years; 1 119 136 [56.9%] female), 867 183 (44.1%) self-identified as non-Hispanic Black and 1 099 506 (55.9%) self-identified as non-Hispanic White. Results were adjusted for age, sex, Medicaid eligibility category, zip code, health status, and usual source of care. On average, annual spending on Black adult (19 years or older) Medicaid enrollees was $317 (95% CI, $259-$375) lower than White enrollees, a 6% difference. Among children (18 years or younger), annual spending on Black enrollees was $256 (14%) lower (95% CI, $222-$290). Adult Black enrollees also had 19.3 (95% CI, 16.78-21.84), or 4%, fewer primary care encounters per 100 enrollees per year compared with White enrollees. Among children, the differences in primary care utilization were larger: Black enrollees had 90.1 (95% CI, 88.2-91.8) fewer primary care encounters per 100 enrollees per year compared with White enrollees, a 23% difference. Black enrollees had lower utilization of most other services, including high-value prescription drugs, but higher emergency department use and rates of HEDIS preventive screenings. Conclusions And Relevance: In this cross-sectional study of US Medicaid enrollees in 3 states, Black enrollees generated lower spending and used fewer services, including primary care and recommended care for acute and chronic conditions, but had substantially higher emergency department use. While Black enrollees had higher rates of HEDIS preventive screenings, ensuring equitable access to all services in Medicaid must remain a national priority.
States have increasingly outsourced the provision of Medicaid services to private managed care plans. To ensure that plans maintain access to care, many states set network adequacy standards that require plans to contract with a minimum number of physicians. In this study we used data from the period 2015-17 for four states to assess the level of Medicaid participation among physicians listed in the provider network directories of each managed care plan. We found that about one-third of outpatient primary care and specialist physicians contracted with Medicaid managed care plans in our sample saw fewer than ten Medicaid beneficiaries in a year. Care was highly concentrated: 25 percent of primary care physicians provided 86 percent of the care, and 25 percent of specialists, on average, provided 75 percent of the care. Our findings suggest that current network adequacy standards might not reflect actual access; new methods are needed that account for beneficiaries’ preferences and physicians’ willingness to serve Medicaid patients.
Background: Risk adjustment is used widely in payment systems and performance assessments, but the extent to which it distinguishes plan or provider effects from confounding due to patient differences is typically unknown. Objective: To assess the degree to which risk-adjusted measures of health plan performance adequately adjust for the variation across plans that arises because of differences in patient characteristics (residual confounding). Design: Comparison between plan performance estimates based on enrollees who made plan choices (observational population) and estimates based on enrollees assigned to plans (randomized population). Setting: Natural experiment in which more than two thirds of a state’s Medicaid population in 1 region was randomly assigned to 1 of 5 plans. Participants: 137 933 enrollees in 2013 to 2014, of whom 31.1% selected a plan and 68.9% were randomly assigned to 1 of the same 5 plans. Measurements: Annual total spending (that is, payments to providers), primary care use, dental care use, and avoidable emergency department visits, all scored as plan-specific deviations from the “average” plan performance within each population. Results: Enrollee characteristics were appreciably imbalanced across plans in the observational population, as expected, but were not in the randomized population. Annual total spending varied across plans more in the observational population (SD, $147 per enrollee) than in the randomized population (SD, $70 per enrollee) after accounting for baseline differences in the observational and randomized populations and for differences across plans. On average, a plan’s spending score (its deviation from the “average” performance) in the observational population differed from its score in the randomized population by $67 per enrollee in absolute value (95% CI, $38 to $123), or 4.2% of mean spending per enrollee ( P = 0.009, rejecting the null hypothesis that this difference would be expected from sampling error). The difference was reduced modestly by risk adjustment to $62 per enrollee ( P = 0.012). Residual confounding was similarly substantial for most other performance measures. Further adjustment for social factors did not materially change estimates. Limitation: Potential heterogeneity in plan effects between the 2 populations. Conclusion: Residual confounding in risk-adjusted performance assessments can be substantial and should caution policymakers against assuming that risk adjustment isolates real differences in plan performance. Primary Funding Source: Arnold Ventures.
2021
This cross-sectional regression discontinuity analysis compares deaths slightly younger and older than 65 years to examine the relationship between access to health insurance coverage and COVID-19 mortality.
Importance: Medicare provides nearly universal health insurance to individuals at age 65 years. How eligibility for Medicare affects racial and ethnic disparities in access to care and health is poorly understood. Objective: To assess the association of Medicare with racial and ethnic disparities in access to care and health. Design, Setting, And Participants: This cross-sectional study uses regression discontinuity to compare racial and ethnic disparities before and after age 65 years, the age at which US adults are eligible for Medicare. There are a total of 2 434 320 respondents in the Behavioral Risk Factor Surveillance System and 44 587 state-age-year observations in the US Centers for Disease Control and Prevention Wide-Ranging Online Data for Epidemiologic Research Data (eg, the mortality rate for individuals age 63 years in New York in 2017) from January 2008 to December 2018. The data were analyzed between February and May 2021. Exposures: Eligibility for Medicare at age 65 years. Main Outcomes And Measures: Proportions of respondents with health insurance, as well as self-reported health and mortality. To examine access, whether respondents had a usual source of care, encountered cost-related barriers to care, or received influenza vaccines was assessed. Results: Of 2 434 320 participants, 192 346 were Black individuals, 104 294 were Hispanic individuals, and 892 177 were men. Immediately after age 65 years, insurance coverage increased more for Black respondents (from 86.3% to 95.8% or 9.5 percentage points; 95% CI, 7.6-11.4) and Hispanic respondents (from 77.4% to 91.3% or 13.9 percentage points; 95% CI, 12.0-15.8) than White respondents (from 92.0% to 98.5% or 6.5 percentage points; 95% CI, 6.1-7.0). This was associated with a 53% reduction compared with the size of the disparity between White and Black individuals before age 65 years (5.7% to 2.7% or 3.0 percentage points; 95% CI, 0.9-5.1; P = .003) and a 51% reduction compared with the size of the disparity between White and Hispanic individuals before age 65 years (14.6% to 7.2% or 7.4 percentage points; 95% CI, 5.3-9.5; P < .001). Medicare eligibility was associated with narrowed disparities between White and Hispanic individuals in access to care, lowering disparities in access to a usual source of care from 10.5% to 7.5% (P = .05), cost-related barriers to care from 11.4% to 6.9% (P < .001), and influenza vaccination rates from 8.1% to 3.3% (P = .01). For disparities between White and Black individuals, access to a usual source of care before and after age 65 years was not significantly different: 1.2% to 0.0% (P = .24), cost-related barriers to care from 5.8% to 4.3% (P = .22), and influenza vaccinations from 11.0% to 10.3% (P = .60). The share of people in poor self-reported health decreased by 3.8 percentage points for Hispanic respondents, 2.6 percentage points for Black respondents, and 0.2 percentage points for White respondents. Mortality-related disparities at age 65 years were unchanged. Medicare’s association with reduced disparities largely persisted after the US Affordable Care Act took effect in 2014. Conclusions And Relevance: In this cross-sectional study that uses a regression discontinuity design, eligibility for Medicare at age 65 years was associated with marked reductions in racial and ethnic disparities in insurance coverage, access to care, and self-reported health.
Axios · AARP · Healthcare Dive
Importance: Hospital advertising has been touted as a tool to improve consumer decision-making, but little is known about its association with objective measures of hospital quality. Objective: To document recent trends in hospital advertising in the US and examine the association between concurrent measures of hospital advertising and quality. Design, Setting, And Participants: Retrospective cross-sectional study of all general acute care hospitals operating in the US between January 2008 and December 2016. Data were analyzed from December 6, 2019, to July 15, 2020. Exposure: Annualized advertising spending for each hospital as measured by a market research firm. Main Outcomes And Measures: Four composites of hospital performance from the Centers for Medicare & Medicaid Services Hospital Compare database were used: risk-standardized mortality rate, risk-standardized readmission rate, Consumer Assessment of Healthcare Providers & Systems (CAHPS) Overall Patient Experience Rating (scale of 1-5; higher scores indicate a more positive patient experience rating), and overall 5-star rating. Linear models adjusted for hospital bed size, hospital revenue, and geographic census region. Results: The study sample included, on average, 4569 general acute care hospitals per year between 2008 and 2016. During this time, approximately half of acute care hospitals (2239 of 4569 [49%]) advertised their services to consumers and spent a total of $3.39 billion. Relative to hospitals that never advertised, advertising hospitals were more likely to be nonprofit facilities (mean [SD], 66% [47%] vs 51% [50%]; P < .001), had larger bed sizes (mean [SD], 234.3 [210.7] beds vs 84.8 [110.6] beds; P < .001), and had higher net incomes (mean [SD], $17 800 000 [$49 000 000] vs $134 099 [$51 600 000]; P < .001). There was no observed association between hospital advertising and performance. For example, hospitals that advertised had a mean (SD) CAHPS 5-star rating of 3.2 (0.9) stars compared with 3.3 (1.0) stars among hospitals that did not advertise, an insignificant difference (P = .92). We observed no difference in performance between advertising and nonadvertising hospitals in 30-day readmission rates (mean [SD], 15.5% [0.8%] vs 15.6% [1.0%]; P = .25), mortality rates (mean [SD], 12.7% [4.0%] vs 12.0% [4.1%]; P = .46), and overall 5-star hospital ratings (mean [SD], 3.1 [0.8] stars vs 3.0 [0.9] stars; P = .50). A significant difference was observed in adjusted mortality rates across terciles of advertising spending, with lower mortality rates for the hospitals with higher ad spending (2016, mean [SD] mortality composite for hospitals in the highest tercile, 11.2% [4.2%] vs hospitals in the middle tercile, 12.0% [3.8%], and for hospitals in the lowest tercile, 12.7% [4.1%]; P = .003). Conclusions And Relevance: The results of this cross-sectional study suggest that the amount hospitals spent on direct-to-consumer advertising was not associated with publicly reported measures of hospital quality; instead, hospital advertising spending was higher for financially stable hospitals with higher net incomes.
In the context of concerns about the appropriateness and costs to insurers and patients of laboratory testing, this study uses data from the IBM MarketScan Commercial Claims and Encounters Database to examine out-of-network laboratory test spending, utilization, and prices in the US in 2008-2016.
2020
Background: Medicaid managed care plans change provider networks frequently, yet there is no evidence about the performance of exiting providers relative to those that remain. Objectives: To investigate the association between provider cost and quality and network exit. Design: Observational study with provider network directory data linked to administrative claims from managed care plans in Tennessee’s Medicaid program during the period 2010-2016. Participants: 1,966,022 recipients assigned to 9593 unique providers. Main Measures: Exposures were risk-adjusted total costs of care and nine measures from the Healthcare Effectiveness Data and Information Set (HEDIS) were used to construct a composite annual indicators of provider performance on quality. Outcome was provider exit from a Medicaid managed care plan. Differences in quality and cost between providers that exited and remained in managed care networks were estimated using a propensity score model to match exiting to nonexiting providers. Key Results: Over our study period, we found that 21% of participating providers exited at least one of the Medicaid managed care plans in Tennessee. As compared with providers that remained in networks, those that exited performed 3.8 percentage points [95% CI, 2.3, 5.3] worse on quality as measured by a composite of the nine HEDIS quality metrics. However, 22% of exiting providers performed above average in quality and cost and only 29% of exiting providers had lower than average quality scores and higher than average costs. Overall, exiting providers had lower aggregate costs in terms of the annual unadjusted cost of care per-member-month - $21.57 [95% CI, - $41.02, - $2.13], though difference in annual risk-adjusted cost per-member-month was nonsignificant. Conclusions: Providers exiting Medicaid managed care plans appear to have lower quality scores in the year prior to their exit than the providers who remain in network. Our study did not show that managed care plans disproportionately drop high-cost providers.
While out-of-network or potential “surprise” billing has garnered increasing attention, particularly in emergency department and inpatient settings, few national studies have examined out-of-network care overall or in other settings. We examined out-of-network spending and use among two large nationwide populations with employer-sponsored insurance. In a primary sample of 27,883,040 people in data for 2008-16 from the Truven MarketScan Commercial Claims and Encounters Database, we found that the unadjusted share of total spending that occurred out of network decreased from 7.0 percent in 2008-10 to 6.1 percent in 2014-16, an adjusted average decline of 0.10 percentage points per year. Using a secondary sample of 13,093,209 people in the Health Care Cost Institute database provided qualitatively similar results, including when provider charges (upper bound for balance billing) were used in place of observed out-of-network prices. In subgroup analyses of the primary sample, the share of out-of-network spending was stable or declined among all segments of care except hospitalist services, pathologist services, and laboratory tests across the study period. Out-of-network use demonstrated comparable patterns. Prices were higher out of network than in network. Policy makers should focus their efforts on protecting consumers from balance billing or potential surprise billing in clinical scenarios where patients often have little choice over their provider.
Importance: Several recent policy proposals have sought to expand the role of Medicaid in providing health insurance for low-income Americans, but there is little recent information on how physician participation in Medicaid compares with alternative forms of coverage for low-income Americans. Objective: To compare the number of office-based physicians included in Medicaid managed care and health insurance exchange plans that operate in the same geographic markets. Design, Setting, And Participants: This cross-sectional study used administrative data from physician network directories and survey data from office-based physicians for Kansas, Nebraska, New York, Tennessee, and Washington. The number of participants totaled 67 057 office-based physicians in the 5 sample states. Data were collected and analyzed from May 2018 to June 2019. Exposures: Physician participation in a Medicaid managed care or health insurance exchange plan network. Main Outcomes And Measures: The percentage of office-based physicians in a county who indicated during a phone survey that they participated in Medicaid; the percentage of office-based physicians in a county who participated in each Medicaid managed care and health insurance exchange plan network; and the percentage of office-based physicians in a county who participated in at least 1 Medicaid managed care plan or, separately, at least 1 health insurance exchange plan. Results: Of the 67 057 office-based physicians in our sample, 49 983 reported in a telephone survey that they accepted Medicaid. This survey-based measure undercounted the percentage of physicians participating in Medicaid by 5.2% (95% CI, 2.3%-8.1%; P < .001) relative to a measure based on physician network directories. Medicaid managed care physician networks covered a median (interquartile range) of 63.4% (48.0%-81.3%) of office-based physicians compared with health insurance exchange physician networks, which covered 51.0% (31.0%-70.5%). In adjusted analyses, Medicaid managed care plans covered 6.2% (95% CI, 3.2%-9.3%, P < .001) more office-based physicians than health insurance exchange plans operating in the same counties. In the states where the same insurers participated in both markets (New York, Tennessee, Washington), the Medicaid managed care physician networks were 6.5% (95% CI, 3.2%-9.8%, P < .001) larger than the health insurance exchange networks offered by the same insurer. Conclusions And Relevance: In this cross-sectional study of physician network data, Medicaid managed care physician networks included more office-based physicians than the physician networks of health insurance exchange plans operating in the same geographic markets. This suggests that Medicaid remains a viable option for expanding coverage in the United States.
2016
To slow the growth of Medicare spending, some policy makers have advocated raising the Medicare eligibility age from the current sixty-five years to sixty-seven years. For the majority of affected adults, this would delay entry into Medicare and increase the time they are covered by private insurance. Despite its policy importance, little is known about how such a change would affect national health care spending, which is the sum of health care spending for all consumers and payers-including governments. We examined how spending differed between Medicare and private insurance using longitudinal data on imaging and procedures for a national cohort of individuals who switched from private insurance to Medicare at age sixty-five. Using a regression discontinuity design, we found that spending fell by $38.56 per beneficiary per quarter-or 32.4 percent-upon entry into Medicare at age sixty-five. In contrast, we found no changes in the volume of services at age sixty-five. For the previously insured, entry into Medicare led to a large drop in spending driven by lower provider prices, which may reflect Medicare’s purchasing power as a large insurer. These findings imply that increasing the Medicare eligibility age may raise national health care spending by replacing Medicare coverage with private insurance, which pays higher provider prices than Medicare does.
The Affordable Care Act has led to significant gains in insurance coverage and reduced the cost of preventive care for millions of Americans. There is considerable interest in understanding how these changes will impact the use of preventive care services and health outcomes. Obtaining unbiased estimates of the impact of insurance on these outcomes is challenging because of inherent differences between insured and uninsured individuals. This article reviews common experimental and quasi-experimental approaches researchers have used in the past to address this problem, including RCTs, differences-in-differences analyses, and regression discontinuity. In each case, the key assumptions underlying the models are discussed alongside some of the main research findings related to prevention and health. The review concludes with a discussion of how experimental and quasi-experimental methods can be used to study the impact of the Affordable Care Act on preventive care and health outcomes.
2015
Objective: To compare methods of price measurement in health care markets. Data Sources: Truven Health Analytics MarketScan commercial claims. Study Design: We constructed medical prices indices using three approaches: (1) a “sentinel” service approach based on a single common service in a specific clinical domain, (2) a market basket approach, and (3) a spending decomposition approach. We constructed indices at the Metropolitan Statistical Area level and estimated correlations between and within them. Principal Findings: Price indices using a spending decomposition approach were strongly and positively correlated with indices constructed from broad market baskets of common services (r > 0.95). Prices of single common services exhibited weak to moderate correlations with each other and other measures. Conclusions: Market-level price measures that reflect broad sets of services are likely to rank markets similarly. Price indices relying on individual sentinel services may be more appropriate for examining specialty- or service-specific drivers of prices.
2013
Background: Prior to 2010, Medicare payments for consultations (commonly billed by specialists) were substantially higher than for office visits of similar complexity (commonly billed by primary care physicians). In January 2010, Medicare eliminated consultation payments from the Part B Physician Fee Schedule and increased fees for office visits. This change was intended to be budget neutral and to decrease payments to specialists while increasing payments to primary care physicians. We assessed the impact of this policy on spending, volume, and complexity for outpatient office encounters in 2010. Methods: We examined outpatient claims from 2007 through 2010 for 2 247 810 Medicare beneficiaries with Medicare Supplemental (Medigap) coverage through large employers in the Thomson Reuters MarketScan Database. We used segmented regression analysis to study changes in spending, volume, and complexity of office encounters adjusted for age, sex, health status, secular trends, seasonality, and hospital referral region. Results: “New” office visits largely replaced consultations in 2010. An average of $10.20 more was spent per beneficiary per quarter on physician encounters after the policy (6.5% increase). The total volume of physician encounters did not change significantly. The increase in spending was largely explained by higher office-visit fees from the policy and a shift toward higher-complexity visits to both specialists and primary care physicians. Conclusions: The elimination of consultations led to a net increase in spending on visits to both primary care physicians and specialists. Higher prices, partially owing to the subjectivity of codes in the physician fee schedule, explained the spending increase, rather than higher volumes.