Changes in inpatient payer-mix and hospitalizations following Medicaid expansion: Evidence from all-capture hospital discharge data

Effects of Affordable Care Act on uninsured hospitalization: Evidence from Texas

OBJECTIVE

To examine the impact of the Affordable Care Act (ACA) health insurance exchanges (Marketplace) on the rate of uninsured discharges in Texas.

DATA SOURCE AND STUDY SETTING

Secondary discharge data from 2011 to 2019 from Texas.

STUDY DESIGN

We conducted a retrospective study estimating the effects of the ACA Marketplace using difference-in-difference regressions, with the main outcome being the uninsured discharge rate. We stratified our sample by patient's race, age, gender, urbanicity, major diagnostic categories (MDC), and emergent type of admissions.

DATA COLLECTION/EXTRACTION METHODS

We used Texas hospital discharge records for non-elderly adults collected by the state of Texas and included acute care hospitals who reported data from 2011 to 2019.

PRINCIPAL FINDINGS

The expansion of insurance through ACA Marketplaces led to reductions in the uninsured discharge rate by 9.9% (95% CI, -17.5%, -2.3%) relative to the baseline mean. The effects of the ACA were felt strongest in counties with any share of Hispanic, in counties with a larger population of Black, and other racial groups, in counties with a significant share of female and older age individuals, in counties considered to be urban, in high-volume diagnoses, and emergent type of admissions.

CONCLUSIONS

These findings indicate that the ACA facilitated a shift in hospital payor mix from uninsured to insured.

Evaluating the impact of the Medicaid expansion program on diabetes hospitalization

Diabetes is the most expensive chronic disease in the United States, and hospital inpatient care accounts for 30% of the total medical expenditures. Medical costs for people with limited resources are covered by Medicaid, a joint federal and state program, and its expansion that extent the coverage to those with incomes up to 138% of the federal poverty level. We investigated the impact of Medicaid expansion on diabetes hospitalizations by states and payer, among adults aged 19 to 64 years old, 5 years after the expansion. We found that Medicaid expansion decreased total diabetes hospitalization in most states and a diabetes hospitalization payer mix shifted from private insurance and uninsured to Medicaid. The percentage of diabetes hospitalizations paid by Medicaid increased by 11% (95% CI 7%, 16%), while the percentage paid by private insurance decreased by 6% (95% CI - 8%, - 3%) and the percentage of uninsured diabetes hospitalization decreased by 13% (95% CI - 18%, - 9%).

Medicaid Expansion and Racial-Ethnic and Sex Disparities in Cardiovascular Diseases Over 6 Years: A Generalized Synthetic Control Approach

BACKGROUND

Studies have suggested Medicaid expansion enacted in 2014 has resulted in a reduction in overall cardiovascular disease (CVD) mortality in the United States. However, it is unknown whether Medicaid expansion has a similar effect across race-ethnicity and sex. We investigated the effect of Medicaid expansion on CVD mortality across race-ethnicity and sex.

METHODS

Data come from the behavioral risk factor surveillance system and the US Centers for Disease Control's Wide-ranging Online Data for Epidemiologic Research, spanning the period 2000-2019. We used the generalized synthetic control method, a quasi-experimental approach, to estimate effects.

RESULTS

Medicaid expansion was associated with -5.36 (mean difference [MD], 95% confidence interval [CI] = -22.63, 11.91) CVD deaths per 100,000 persons per year among Blacks; -4.28 (MD, 95% CI = -30.08, 21.52) among Hispanics; -3.18 (MD, 95% CI = -8.30, 1.94) among Whites; -5.96 (MD, 95% CI = -15.42, 3.50) among men; and -3.34 (MD, 95% CI = -8.05, 1.37) among women. The difference in mean difference (DMD) between the effect of Medicaid expansion in Blacks compared with Whites was -2.18; (DMD, 95% CI = -20.20, 15.83); between that in Hispanics compared with Whites: -1.10; (DMD, 95% CI = -27.40, 25.20) and between that in women compared with men: 2.62; (DMD, 95% CI = -7.95, 13.19).

CONCLUSIONS

Medicaid expansion was associated with a reduction in CVD mortality overall and in White, Black, Hispanic, male, and female subpopulations. Also, our study did not find any difference or disparity in the effect of Medicaid on CVD across race-ethnicity and sex-gender subpopulations, likely owing to imprecise estimates.

The impact of Medicaid expansion on mental health and substance use related inpatient visits

OBJECTIVE

Under the Affordable Care Act, many states expanded their Medicaid eligibility, allowing individuals living at or below 138% of the Federal Poverty Level to receive insurance coverage. As a result, forty states and the District of Columbia have expanded Medicaid to date. Although Medicaid expansion is expected to increase access to care in general, it is not evident if it has helped increase access to mental health and substance use-related healthcare, especially in inpatient settings. Therefore, this study examines the impact of Medicaid expansion on mental health and substance use- (MHSU) related inpatient visits and the variation in payer mix.

METHODS

This study utilizes state-level quarterly inpatient visit data from the Healthcare Cost and Utilization Project's Fast Stats Database from 2005 to 2019 and performs difference-in-differences regression analyses to compare MHSU-related inpatient visit data in expansion and non-expansion states for all visits and by payer. Analyses controlled for state-level socio-demographic and health policy variables.

RESULTS

Findings indicate that Medicaid expansion did not significantly affect overall MHSU-related inpatient visits. However, Medicaid expansion was associated with 22.74% increase (P < 0.01; 95% CI: 17.76, 27.71) in the Medicaid share of MHSU-related inpatient visits, 18.31% reduction (P < 0.01; 95% CI: -22.54, -14.09) in the uninsured share of MHSU-related inpatient visits, and 4.42% reduction (P < 0.05; 95% CI: -7.83, -1.01) in the privately insured share of MHSU-related inpatient visits in expansion states compared with non-expansion states.

CONCLUSIONS

Findings show that Medicaid expansion significantly affects the payer mix associated with MHSU-related inpatient visits while it has no significant impact on the overall MHSU-related inpatient visits.

The Effects of the Medicaid Expansion on Hospital Utilization, Employment, and Capital

In recent years, hospitals reacted to changes in demand caused by the Affordable Care Act Medicaid expansions. We conducted a difference-in-differences analysis that compared changes to hospital demand and supply in Medicaid expansion and nonexpansion states. We used 2010-2016 data from the American Hospital Association and the Healthcare Cost Report Information System to quantify changes to hospital utilization and characterize how hospitals adjusted labor and capital inputs. During the period studied, the Medicaid expansion was associated with increases in emergency department visits and other outpatient hospital visits. We find strong evidence that hospitals met increases in demand by hiring nursing staff and weaker evidence that they increased hiring of technicians and investments in equipment. We found no evidence that hospitals adjusted hiring of physicians, support staff, or investments in other capital inputs.

Younger Individuals Increase Their Use of Nursing Homes Following ACA Medicaid Expansion

OBJECTIVES

This study examines the effect of Medicaid eligibility expansion under the Affordable Care Act (ACA) on the utilization of nursing home services by younger individuals and those covered by Medicaid.

DESIGN

Compared the age of nursing home residents, proportion of individuals covered by Medicaid, annual nursing home admissions in those younger than 65, and nursing home length of stay in states that expanded Medicaid eligibility through the ACA to states that did not. We used data from LTCFocus (nursing home level), the Minimum Data Set (individual level), and Medicaid expansion status from the Kaiser Family Foundation.

SETTING AND PARTICIPANTS

The study included 15,005,888 nursing home admissions, 2,446,950 of which were residents younger than 65, across 14,132 nursing homes between 2009 and 2016.

METHODS

A time-varying difference-in-difference model including state and year fixed effects with effect modification by pre-2014 nursing home occupancy.

RESULTS

Facilities in expansion states with a pre-ACA occupancy rate of more than 70% increased the fraction of residents younger than 65 by 2.74% to 6.32%, compared with similar facilities in nonexpansion states. Medicaid admissions varied, with an increase in year 2 after expansion compared with nonexpansion states. Among residents entering from an acute care hospital, the proportion younger than 65 increased in facilities with pre-2014 occupancy rates of more than 70%, compared with similar facilities in nonexpansion states, an increase of up to 6.51%. Median nursing home length of stay for individuals younger than 65 decreased relative to nonexpansion states across all occupancy categories, ranging from 1.68 to 6.06 days after Medicaid expansion.

CONCLUSIONS AND IMPLICATIONS

Medicaid expansion increased access to nursing home post-acute care for individuals younger than 65. It remains unclear if the benefit of post-acute care is the same among this group, or if the needs of younger individuals can be adequately met in this setting.

The ACA Medicaid Expansion And Perinatal Insurance, Health Care Use, And Health Outcomes: A Systematic Review

The Affordable Care Act (ACA) Medicaid expansion increased Medicaid eligibility for low-income adults regardless of their pregnancy or parental status. Variation in states' adoption of this expansion created a natural experiment to study the effects of expanding public insurance on insurance coverage, health care use, and health outcomes during preconception, pregnancy, and postpartum. We conducted a systematic review of relevant literature on this topic, analyzing twenty-four studies published between January 2014 and April 2021. We found that the ACA Medicaid expansion increased preconception and postpartum Medicaid coverage with corresponding declines in uninsurance, private insurance coverage, and insurance churn. There was limited evidence that Medicaid expansion increased perinatal health care use or improved infant birth outcomes overall, although some studies reported reduced racial and ethnic disparities in rates of prenatal and postpartum visit attendance, maternal mortality, low birthweight, and preterm births. Stronger data collection on preconception and postpartum outcomes with sufficient sample sizes to stratify by race and ethnicity is needed to assess the full impact of the ACA and emerging Medicaid policy changes, such as the postpartum Medicaid extension.

How Would Medicaid Expansion Affect Texas Hospitals? Evidence From a Retrospective Quasi-Experimental Study

This study aims to estimate the impact of a potential Medicaid expansion on Texas hospitals. The Affordable Care Act (ACA) Medicaid expansion increased access to health care and improved health outcomes. Still, several states, including Texas, have not adopted the expansion. This is a retrospective quasi-experimental study. We obtained inpatient data containing discharges from Texas hospitals between 2010 and 2017 from the Texas Department of State Health Services. Texas hospitals receive a significant number of patients from the adjacent states. We use a difference-in-differences methodology, where the patients from the neighboring states that expanded Medicaid in 2014 are the treatment group, and those that reside in Texas are the control group. The outcome variables are the payer mix and the cost of treatment, proxied by Diagnoses Related Group (DRG) weights assigned by the Centers for Medicare and Medicaid Services (CMS). The Medicaid expansion is associated with 4.15% lower costs of treatment among the patients from the expansion states (P < .01). Also, the uninsured rate decreased by 4.7 percentage points (from 11.3%, P < .01), while the share of Medicaid patients increased by 10.9 percentage points (from 30.7%, P < .01). There are no significant changes in the share of privately insured or Medicare patients. Texas hospitals can benefit significantly from Medicaid expansion due to reductions in average treatment costs and the share of the uninsured.

Changes in Health Care Access and Utilization for Low-SES Adults Aged 51-64 Years After Medicaid Expansion

OBJECTIVES

Whether the Affordable Care Act (ACA) insurance expansions improved access to care and health for adults aged 51-64 years has not been closely examined. This study examined longitudinal changes in access, utilization, and health for low-socioeconomic status adults aged 51-64 years before and after the ACA Medicaid expansion.

METHODS

Longitudinal difference-in-differences (DID) study before (2010-2014) and after (2016) Medicaid expansion, including N = 2,088 noninstitutionalized low-education adults aged 51-64 years (n = 633 in Medicaid expansion states, n = 1,455 in nonexpansion states) from the nationally representative biennial Health and Retirement Study. Outcomes included coverage (any, Medicaid, and private), access (usual source of care, difficulty finding a physician, foregone care, cost-related medication nonadherence, and out-of-pocket costs), utilization (outpatient visit and hospitalization), and health status.

RESULTS

Low-education adults aged 51-64 years had increased rates of Medicaid coverage (+10.6 percentage points [pp] in expansion states, +3.2 pp in nonexpansion states, DID +7.4 pp, p = .001) and increased likelihood of hospitalizations (+9.2 pp in expansion states, -1.1 pp in nonexpansion states, DID +10.4 pp, p = .003) in Medicaid expansion compared with nonexpansion states after 2014. Those in expansion states also had a smaller increase in limitations in paid work/housework over time, compared to those in nonexpansion states (+3.6 pp in expansion states, +11.0 pp in nonexpansion states, DID -7.5 pp, p = .006). There were no other significant differences in access, utilization, or health trends between expansion and nonexpansion states.

DISCUSSION

After Medicaid expansion, low-education status adults aged 51-64 years were more likely to be hospitalized, suggesting poor baseline access to chronic disease management and pent-up demand for hospital services.

The impact of Medicaid expansion on emergency department wait times

OBJECTIVE

To estimate the impact of Medicaid expansion on emergency department (ED) wait times.

DATA SOURCES

We used 2012-2017 hospital-level secondary data from the CMS Hospital Compare data warehouse.

STUDY DESIGN

We used a state-level difference-in-differences approach to identify the impact of Medicaid expansion on four measures of ED wait times: time before being seen by a provider; time before being sent home after being seen by a provider; boarding time spent in the ED waiting to be discharged to an inpatient room; and the percentage of patients who left without being seen. We compared outcomes in states that expanded Medicaid with those in states that did not expand Medicaid.

DATA COLLECTION/EXTRACTION METHODS

Our sample included all US acute care hospitals with EDs in states that did not ever expand Medicaid or that fully expanded Medicaid in January of 2014.

PRINCIPAL FINDINGS

Medicaid expansion was associated with a 3.1-min increase (SE: 0.994, baseline mean: 30.8 min) in the time spent waiting to see an ED provider, a relative increase of 10%. Patients who were eventually sent home after being seen by a provider experienced a 7.5-min increase (SE: 1.8, baseline mean 142.1 min) in wait time. Boarding time rose by 3.8 min (SE 1.9, baseline mean 111.4 min). The percentage of patients who left without being seen rose by 0.3 percentage points (SE: 0.09, baseline mean 2.0), a relative increase of 15.3%.

CONCLUSIONS

This study provides multistate evidence that Medicaid expansion increased ED wait times for patients, indicating that ED crowding may have worsened post-expansion. Future work should aim to uncover the mechanisms through which insurance expansion increased ED wait times to provide policy direction.

Impact of Medicaid expansion on mental health and substance use related emergency department visits

Background: Although Medicaid expansion under the Affordable Care Act reduces uninsurance, little evidence exists on its impact on mental health and substance use (MHSU) related healthcare utilization. Therefore, the objectives of this study are to examine the impact of Medicaid expansion on emergency department visits related to mental health and substance use disorders and to examine its effect on the variation in payer mix. Methods: The study utilizes state-level quarterly emergency department (ED) visit data from Healthcare Cost and Utilization Project's Fast Stats Database, along with state socio-demographic and health policy data for the analysis. A difference-in-differences regression analysis approach was utilized in comparing MHSU-related ED visit data between expansion and non-expansion states from 2006 to 2019 for all visits and by payer mix. Results: Medicaid expansion was associated with additional 0.35 non-Medicare adult MHSU-related ED visits per 1,000 population (p < 0.05) in expansion states compared with non-expansion states. In addition, Medicaid expansion was associated with about 20.4% increase (p < 0.01) in Medicaid-share of MHSU-related ED visits, about 17.4% reduction (p < 0.01) in uninsured-share of MHSU-related ED visits, and about 3% reduction (p < 0.05) in privately-insured share of MHSU-related ED visits in expansion states compared with non-expansion states. Conclusions: The findings indicate that Medicaid expansion was associated with increased MHSU-related ED visits among the Medicaid population and the overall non-Medicare adult population, while it was associated with reductions in MHSU-related ED visits among the uninsured and privately-insured populations in expansion states compared with non-expansion states.

Insurance expansions and hospital utilization: Relabeling and reabling?

The 2010 Patient Protection & Affordable Care Act (ACA) significantly expanded access to private and public health insurance for low-income individuals through income-based subsidies and income-based eligibility expansions, respectively. In this paper, we use the universe of hospitals from 2009 to 2015 to characterize how these expansions affected the financing of hospital visits, along with price, utilization, and potential spillovers in the quality of care. The insurance coverage expansions generated a shift in the composition of payers and a modest increase in the utilization of hospital outpatient services. While concerns have been raised that these shifts in utilization could cause negative spillovers to the already insured population (e.g., Medicare enrollees), we find no significant change in the quality of care experienced by those already insured. The primary result of both federally funded insurance expansions was to increase the profits generated and prices charged by the hospitals providing such services.

Medicaid Expansion Increased Preconception Health Counseling, Folic Acid Intake, And Postpartum Contraception

The period before pregnancy is critically important for the health of a woman and her infant, yet not all women have access to health insurance during this time. We evaluated whether increased access to health insurance under the Affordable Care Act Medicaid expansions affected ten preconception health indicators, including the prevalence of chronic conditions and health behaviors, birth control use and pregnancy intention, and receipt of preconception health services. By comparing changes in outcomes for low-income women in expansion and nonexpansion states, we document greater preconception health counseling, prepregnancy folic acid intake, and postpartum use of effective birth control methods among low-income women associated with Medicaid expansion. We do not find evidence of changes on the other preconception health indicators examined. Our findings indicate that expanding Medicaid led to detectable improvements on a subset of preconception health measures.

Coverage for Adults With Chronic Disease Under the First 5 Years of the Affordable Care Act

BACKGROUND

A key goal of the Patient Protection and Affordable Care Act (ACA) was to increase health insurance coverage for people with chronic disease. Little is known about progress toward this goal over the first 5 years of ACA implementation.

OBJECTIVE

The objective of this study was to assess changes in coverage for nonelderly adults with and without chronic disease over the first 5 years of ACA implementation, and the effects of state-level Medicaid eligibility expansions on coverage for these populations.

RESEARCH DESIGN

Multivariable and difference-in-differences regression models.

PARTICIPANTS

A total of 2,007,271 adults aged 18-64 years in the nationally representative Behavioral Risk Factor Surveillance System 2011-2018 data.

MEASURES

Self-reported insurance coverage.

RESULTS

Over the first 5 years of ACA implementation, coverage increased among nonelderly adults with versus without chronic disease by 6.9 versus 5.4 percentage points, respectively (95% confidence interval: 6.1-7.6, P<0.001, and 4.4-6.3, P<0.001, respectively). State-level Medicaid eligibility expansions were associated with a coverage increase among people with chronic disease of 2.8 percentage points (95% confidence interval: 1.7-3.8, P<0.001). After ACA implementation diminished in 2017, coverage gains for people with chronic disease declined by 0.9 percentage points (P<0.001).

CONCLUSIONS

Coverage significantly improved for people with chronic disease during the first 5 years of ACA implementation, with ACA Medicaid expansions increasing coverage further. After ACA implementation diminished in 2017, coverage gains decreased.

The Effect of Large-scale Health Coverage Expansions in Wealthy Nations on Society-Wide Healthcare Utilization

Most analysts project that a reform like Medicare-for-All that lowers financial barriers to care would cause a surge in the utilization of services, raising costs despite stable or even reduced prices. However, the finite supply of physicians and hospital beds could constrain such utilization increases. We reviewed the effects of 13 universal coverage expansions in capitalist nations on physician and hospital utilization, beginning with New Zealand's 1938 Social Security Act up through the 2010 Affordable Care Act in the USA. Almost all coverage expansions had either a small (i.e., < 10%) or no effect on society-wide utilization. However, coverage expansions often redistributed care-increasing use among newly covered groups while producing small, offsetting reductions among those already covered. We conclude that in wealthy nations, large-scale coverage expansions need not cause overall utilization to surge if provider supply is controlled. However, such reforms could redirect care towards patients who most need it.

Medicaid Expansion and Mechanical Ventilation in Asthma, Chronic Obstructive Pulmonary Disease, and Heart Failure

Rationale: The Affordable Care Act's Medicaid expansion has led to increased access to chronic disease care among newly insured adults. Despite this, its effects on clinical outcomes, particularly for patients with asthma, chronic obstructive pulmonary disease, and heart failure, are uncertain. Objectives: To assess whether Medicaid expansion was associated with changes in mechanical ventilation rates among hospitalized patients with heart failure, asthma, and chronic obstructive pulmonary disease. Methods: Difference-in-differences analysis comparing discharge data from four states that expanded Medicaid in 2014 (Arizona, Iowa, New Jersey, and Washington) and three comparison states that did not (North Carolina, Nebraska, and Wisconsin) was performed. Models were adjusted for patient and hospital factors. Results: Mechanical ventilation rates at baseline were 7.2% in nonexpansion states and 8.8% in expansion states. Medicaid expansion was associated with a decline in mechanical ventilation rates at -0.2% per quarter (95% confidence interval [CI], -0.3% to 0.0%; P = 0.010). We did not observe a change in the rate of ICU admission (-0.4% per quarter; 95% CI, -0.8% to 0.1%; P = 0.10) or in-hospital mortality (0.1% per quarter; 95% CI, 0.0% to 0.1%; P = 0.30). In a negative control among adults aged 65 years or older, changes in mechanical ventilation rates were similar, though the CIs crossed zero (-0.1%; 95% CI, -0.2% to 0.0%; P = 0.08). Conclusions: Medicaid expansion may have been associated with a decline in mechanical ventilation rates among uninsured and Medicaid-covered patients admitted with heart failure, chronic obstructive pulmonary disease, and asthma.

Shifting threats and rhetoric: how Republican governors framed Medicaid expansion

The 2012 Supreme Court decision in National Federation of Independent Business v Sebelius gave states the option to adopt the Medicaid expansion as part of the Affordable Care Act. Many states, especially those under Republican control, have since grappled with their decision to implement the expansion. We conduct a comparative analysis of how Republican governors framed their stance on the Medicaid expansion. We analyze public statements on the Medicaid expansion published in two major in-state newspapers from all Republican governors from June 2012 through June 2018. In total we collected, coded and analyzed 3277 statements from 66 newspapers. Several key themes emerge from our analysis. While every Republican governor used oppositional framing as part of their rhetorical response to the Medicaid expansion, the policy had a destabilizing effect on the previously unified opposition to health reform. We find that Republican framing split after the results of the 2012 election and that overall Republican governors shifted towards more supportive framing prior to the 2016 presidential election. Republican governors transformed how they framed their stance towards Medicaid expansion after Donald Trump was elected in 2016, with both supportive and oppositional moral-based framing of expansion increasing. These findings inform how policymakers use rhetoric to support their stance on controversial policies in a hyper-partisan and polarized political environment.

The Association of Nurse Practitioner Scope-of-Practice Laws With Emergency Department Use: Evidence From Medicaid Expansion

BACKGROUND

Overuse and inappropriate use of emergency departments (EDs) remains an important issue in health policy. After implementation of Medicaid expansion, many states experienced an increase in ED use, but the magnitude varied. Differential access to primary care might explain such variation.

OBJECTIVE

To determine whether the increase in ED use among Medicaid enrollees following Medicaid expansion was smaller in states that allowed greater access to primary care providers by permitting nurse practitioners (NPs) to practice without physician oversight.

RESEARCH DESIGN

Examining data on ED use by Medicaid beneficiaries, we estimated random effects models to examine changes in ED visits. Models for 8 different clinical conditions were estimated, with each model including a linear time trend, indicators for Medicaid expansion and for the absence of physician oversight requirements, and an interaction between these 2 indicators.

RESULTS

States requiring physician oversight of NPs had a 28% increase in ED visits relative to the preexpansion period, while states allowing NP practice without physician oversight had only a 7% increase. The increase in the share of visits covered by Medicaid in no-oversight states was 40% of the size of the increase in oversight states.

CONCLUSIONS

Allowing NPs to practice without physician oversight was associated with a reduction in the magnitude of increase in ED use following Medicaid expansion. States that restrict NP practice should weigh the costs of maintaining these restrictions against the potential benefits of lower ED use. States considering Medicaid expansion should also consider relaxing NP scope-of-practice laws.

Association Between Medicaid Coverage and Income Status on Health Care Use and Costs Among Hypertensive Adults After Enactment of the Affordable Care Act

BACKGROUND

Hypertension is highly prevalent among the low-income population in the United States. This study assessed the association between Medicaid coverage and health care service use and costs among hypertensive adults following the enactment of the Patient Protection and Affordable Care Act (ACA), by income status level.

METHODS

A nationally representative sample of 2,866 nonpregnant hypertensive individuals aged 18-64 years with income up to 138% of the federal poverty level (FPL) were selected from the 2014 and 2015 Medical Expenditure Panel Survey. Regression analyses were performed to examine the association of Medicaid coverage with outpatient (outpatient visits and prescription medication fills), emergency, and acute health care service use and costs among those potentially eligible for Medicaid by income status-the very low-income (FPL ≤ 100%) and the moderately low-income (100% > FPL ≤ 138%).

RESULTS

Among the study population, 70.1% were very low-income and 29.9% were moderately low-income. Full-year Medicaid coverage was higher among the very low-income group (41.0%) compared with those moderately low-income (29.1%). For both income groups, having full-year Medicaid coverage was associated with increased health care service use and higher overall annual medical costs ($13,085 compared with $7,582 without Medicaid); costs were highest among moderately low-income patients ($17,639).

CONCLUSION

Low-income individuals with hypertension, who were potentially newly eligible for Medicaid under the ACA may benefit from expanded Medicaid coverage by improving their access to outpatient services that can support chronic disease management. However, to realize decreases in medical expenditures, efforts to decrease their use of emergency and acute care services are likely needed.

Using Data From the Healthcare Cost and Utilization Project for State Health Policy Research

BACKGROUND

The Healthcare Cost and Utilization Project (HCUP), the nation's most complete source of all-payer hospital care data, supports analyses at the national, regional, state and community levels. However, national HCUP data are often used in inappropriate ways in studies of state-specific issues.

OBJECTIVE

To describe the opportunities and challenges of using HCUP data to conduct state health policy research and to provide empirical examples of what can go wrong when using the national HCUP data inappropriately.

RESEARCH DESIGN

Comparison of results from state-level analyses using national HCUP data and the state-specific HCUP data recommended by the Agency for Healthcare Research and Quality (AHRQ). Analyses included trends in state-specific rates of cesarean delivery and a difference-in-differences analysis of Connecticut's Medicaid expansion.

SUBJECTS

Hospital discharges from the 2004 to 2011 HCUP Nationwide Inpatient Samples (NIS) and State Inpatient Databases (SID).

MEASURES

Cesarean delivery rates, discharges per capita, and discharges by the payer.

RESULTS

State-level estimates derived from the NIS are volatile and often provide misleading policy conclusions relative to estimates from the SID.

CONCLUSIONS

The NIS should not be used for state-level research. AHRQ provides resources to assist analysts with state-specific studies using SID files.

The Effects on Hospital Utilization of the 1966 and 2014 Health Insurance Coverage Expansions in the United States

BACKGROUND

Persons with comprehensive health insurance use more hospital care than those who are uninsured or have high-deductible plans. Consequently, analysts generally assume that expanding coverage will increase society-wide use of inpatient services. However, a limited supply of beds might constrain this growth.

OBJECTIVE

To determine how the implementations of Medicare and Medicaid (1966) and the Patient Protection and Affordable Care Act (ACA) (2014) affected hospital use.

DESIGN

Repeated cross-sectional study.

SETTING

Nationally representative surveys.

PARTICIPANTS

Respondents to the National Health Interview Survey (1962 to 1970) and Medical Expenditure Panel Survey (2008 to 2015).

MEASUREMENTS

Mean hospital discharges and days were measured, both society-wide and among subgroups defined by income, age, and health status. Changes between preexpansion and postexpansion periods were analyzed using multivariable negative binomial regression.

RESULTS

Overall hospital discharges averaged 12.8 per 100 persons in the 3 years before implementation of Medicare and Medicaid and 12.7 per 100 persons in the 4 years after (adjusted difference, 0.2 discharges [95% CI, -0.1 to 0.4 discharges] per 100 persons; P = 0.26). Hospital days did not change in the first 2 years after implementation but increased later. Effects differed by subpopulation: Adjusted discharges increased by 2.4 (CI, 1.7 to 3.1) per 100 persons among elderly compared with nonelderly persons (P < 0.001) and also increased among those with low incomes compared with high-income populations. For younger and higher-income persons, use decreased. Similarly, after the ACA's implementation, overall hospital use did not change: Society-wide rates of discharge were 9.4 per 100 persons before the ACA and 9.0 per 100 persons after the ACA (adjusted difference, -0.6 discharges [CI, -1.3 to 0.2 discharges] per 100 persons; P = 0.133), and hospital days were also stable. Trends differed for some subgroups, and rates decreased significantly in unadjusted (but not adjusted) analyses among persons reporting good or better health status and increased nonsignificantly among those in worse health.

LIMITATION

Data sources relied on participant recall, surveys excluded institutionalized persons, and follow-up after the ACA was limited.

CONCLUSION

Past coverage expansions were associated with little or no change in society-wide hospital use; increases in groups who gained coverage were offset by reductions among others, suggesting that bed supply limited increases in use. Reducing coverage may merely shift care toward wealthier and healthier persons. Conversely, universal coverage is unlikely to cause a surge in hospital use if growth in hospital capacity is carefully constrained.

PRIMARY FUNDING SOURCE

None.

Trends in Hospital Utilization After Medicaid Expansion

BACKGROUND

Medicaid expansion was associated with an increase in hospitalizations funded by Medicaid. Whether this increase reflects an isolated payer shift or broader changes in case-mix among hospitalized adults remains uncertain.

RESEEARCH DESIGN

Difference-in-differences analysis of discharge data from 4 states that expanded Medicaid in 2014 (Arizona, Iowa, New Jersey, and Washington) and 3 comparison states that did not (North Carolina, Nebraska, and Wisconsin).

SUBJECTS

All nonobstetric hospitalizations among patients aged 19-64 years of age admitted between January 2012 and December 2015.

MEASURES

Outcomes included state-level per-capita rates of insurance coverage, several markers of admission severity, and admission diagnosis.

RESULTS

We identified 6,516,576 patients admitted during the study period. Per-capita admissions remained consistent in expansion and nonexpansion states, though Medicaid-covered admissions increased in expansion states (274.6-403.8 per 100,000 people vs. 268.9-262.8 per 100,000; P<0.001). There were no significant differences after Medicaid expansion in hospital utilization, based on per-capita rates of patients-designated emergent, admitted via the emergency department, admitted via clinic, discharged within 1 day, or with lengths of stay ≥7 days. Similarly, there were no differences in diagnosis category at admission, admission severity, comorbidity burden, or mortality associated with Medicaid expansion (P>0.05 for all comparisons).

CONCLUSIONS

Medicaid expansion was associated with a shift in payers among nonelderly hospitalized adults without significant changes in case-mix or in several markers of acuity. These findings suggest that Medicaid expansion may reduce uncompensated care without shifting admissions practices or acuity among hospitalized adults.

Changes in hospital service demand, cost, and patient illness severity following health reform

OBJECTIVE

To estimate the effects of the health insurance exchange and Medicaid coverage expansions on hospital inpatient and emergency department (ED) utilization rates, cost, and patient illness severity, and also to test the association between changes in outcomes and the size of the uninsured population eligible for coverage in states.

DATA SOURCES

Healthcare Cost and Utilization Project State Inpatient and Emergency Department Databases, 2011-2015, Nielsen Demographic Data, and the American Community Survey.

STUDY DESIGN

Retrospective study using fixed-effects regression to estimate the effects in expansion and nonexpansion states by age/sex demographic groups.

FINDINGS

In Medicaid expansion states, rates of uninsured inpatient discharges and ED visits fell sharply in many demographic groups. For example, uninsured inpatient discharge rates across groups, except young females, decreased by ≥39 percent per capita on average in expansion states. In nonexpansion states, uninsured utilization rates remained unchanged or increased slightly (0-9.2 percent). Changes in all-payer and private insurance rates were more muted. Changes in inpatient costs per discharge were negative, and all-payer inpatient costs per discharge declined <6 percent in most age/sex groups. The size of the uninsured population eligible for coverage was strongly associated with changes in outcomes. For example, among males aged 35-54 years in expansion states, there was a 0.793 percent decrease in the uninsured discharge rate per unit increase in the coverage expansion ratio (the ratio of the size of the population eligible for coverage to the size of the previously covered population within an age/sex/payer/geographic group).

CONCLUSIONS

Significant shifts in cost per discharge and patient severity were consistent with selective take-up of insurance. The "treatment intensity" of expansions may be useful for anticipating future effects.

Medicaid Eligibility Expansions May Address Gaps In Access To Diabetes Medications

Diabetes is a top contributor to the avoidable burden of disease. Costly diabetes medications, including insulin and drugs from newer medication classes, can be inaccessible to people who lack insurance coverage. In 2014 and 2015 twenty-nine states and the District of Columbia expanded eligibility for Medicaid among low-income adults. To examine the impacts of Medicaid expansion on access to diabetes medications, we analyzed data on over ninety-six million prescription fills using Medicaid insurance in the period January 2008-December 2015. Medicaid eligibility expansions were associated with thirty additional Medicaid diabetes prescriptions filled per 1,000 population in 2014-15, relative to states that did not expand Medicaid eligibility. Age groups with higher prevalence of diabetes exhibited larger increases. The increase in prescription fills grew significantly over time. Overall, fills for insulin and for newer medications increased by 40 percent and 39 percent, respectively. Our findings suggest that Medicaid eligibility expansions may address gaps in access to diabetes medications, with increasing effects over time.

The Effect of Health Insurance on Prescription Drug Use Among Low-Income Adults:Evidence from Recent Medicaid Expansions

This study examines how subsidized coverage affects prescription drug utilization among low-income non-elderly adults. Using the Affordable Care Act's Medicaid expansions as a source of variation and a national, all-payer pharmacy transactions database, we find that within the first 15 months of new health insurance availability, aggregate Medicaid-paid prescriptions increased 19 percent, amounting to nearly 9 new prescriptions a year, per new enrollee. We find no evidence of reductions in uninsured or privately-insured prescriptions, suggesting that new coverage did not simply substitute for other payment sources. The largest increases occurred for medications treating conditions such as diabetes and heart disease, suggesting greater price elasticity for chronic medications. Generics increased more than brand-name drugs; and utilization increased less in expansion states with higher Medicaid drug copayments. Overall, these findings suggest that prescription drug demand among low-income populations exhibits substantial price sensitivity, and insurance expansion can increase medication treatment for chronic conditions.

Changes in Reimbursement to Emergency Physicians After Medicaid Expansion Under the Patient Protection and Affordable Care Act

STUDY OBJECTIVE

We examine the effect of Medicaid expansion on reimbursement for emergency physicians' professional services.

METHODS

We conducted a retrospective study using data from a national emergency medicine group in a sample of 50 emergency departments (EDs) from July 1, 2012, to June 30, 2015. We categorized facilities in 14 states into full-expansion (23), partial-expansion (17), and nonexpansion (10) categories based on pre-expansion Medicaid eligibility criteria for all adults. We used a difference-in-differences design to assess the effect of Medicaid expansion on provider reimbursement per visit. Secondary outcomes included reimbursement per relative value unit and relative value units per visit, both overall and by payer type, controlling for age, sex, billing codes, and health system relationship.

RESULTS

We studied greater than 6.7 million ED visits during July 2012 to December 2015, 3.0 million pre-expansion and 3.7 million postexpansion. After adjusting for covariates, reimbursement per visit increased 6.3% (95% confidence interval 1.4% to 11.1%) in full-expansion relative to nonexpansion states and did not change significantly in partial-expansion versus nonexpansion states. Reimbursement per visit for commercial insurance increased 17.1% (95% confidence interval 9.9% to 24.2%) in full-expansion versus nonexpansion states. Reimbursement for self-pay visits increased 9.7% (95% confidence interval 3.7% to 15.7%) in full-expansion versus nonexpansion states. Changes in payments were driven by higher reimbursement per relative value unit; relative value units per visit declined slightly in full-expansion compared with nonexpansion states.

CONCLUSION

In this sample, full Medicaid expansion increased payments for emergency physicians' professional services compared with reimbursement in nonexpansion states. Higher reimbursement was driven primarily by lower proportions of uninsured patients and increased reimbursement per visit for both commercially insured and self-pay patients in states with full Medicaid expansion.

Association of State Medicaid Expansion With Rate of Uninsured Hospitalizations for Major Cardiovascular Events, 2009-2014

IMPORTANCE

Cardiovascular disease is the leading primary diagnosis among all hospital discharges, and insurance status is associated with patient outcomes. The association of state-level policy decisions regarding the Affordable Care Act (ACA) Medicaid expansion with rates of uninsured hospitalizations for major cardiovascular events and in-hospital mortality has not been investigated to date.

OBJECTIVE

To investigate whether the rates of uninsured hospitalizations for major cardiovascular events and in-hospital mortality varied by state-level policy on ACA Medicaid expansion.

DESIGN, SETTING, AND PARTICIPANTS

For this cohort study, difference-in-differences analysis of data from the Healthcare Cost and Utilization Project State Inpatient Databases of 30 US states on 524 848 non-Medicare hospitalizations in 2014 and a mean of 516 811 non-Medicare hospitalizations per year from 2009 to 2013 was performed for major cardiovascular events (defined as a composite of acute myocardial infarction, stroke, and heart failure) from January 1, 2009, through December 31, 2014. Analyses were completed September 1, 2017.

EXPOSURE

State Medicaid expansion as of January 1, 2014.

MAIN OUTCOMES AND MEASURES

Comparison of mean payer mix proportions (uninsured, Medicaid, and privately insured) and in-hospital mortality between expansion and nonexpansion states for the years preceding the ACA Medicaid expansion (2009-2013) and the year after the ACA Medicaid expansion (2014).

RESULTS

Of the 801 819 hospitalizations in the 17 expansion states in 2014, 428 503 (53.4%) patients were men, 514 036 (64.1%) were white, and 365 797 (45.6%) were aged 65 to 84 years. Of 719 459 hospitalizations in the 13 nonexpansion states in 2014, 383 311 (53.3%) patients were men, 492 136 (68.4%) were white, and 335 781 (46.7%) were aged 65 to 84 years. There were 281 184 non-Medicare hospitalizations for major cardiovascular events in the 17 expansion states and 243 664 non-Medicare hospitalizations in the 13 nonexpansion states in 2014. In multivariable regression analyses, the expansion states had a significant 5.8-percentage point decrease in the proportion of uninsured hospitalizations after Medicaid expansion relative to the nonexpansion states (adjusted difference-in-differences estimate, -0.058; 95% CI, -0.075 to -0.042; P < .001). The expansion states also had a significant 8.4-percentage point increase in the Medicaid share after Medicaid expansion relative to the nonexpansion states (adjusted difference-in-differences estimate, 0.084; 95% CI, 0.065 to 0.102; P < .001). In-hospital mortality did not change significantly after Medicaid expansion in either the expansion states (before ACA, 3.8% vs after ACA, 3.7%) or the nonexpansion states (4.0% vs 4.0%).

CONCLUSIONS AND RELEVANCE

States that expanded Medicaid during the ACA implementation had a significantly greater reduction in the proportion of uninsured hospitalizations for major cardiovascular events compared with the nonexpansion states. This study suggests that expansion status was not associated with in-hospital mortality rates in the first year after ACA implementation.