The impact of Medicaid expansion on spending and utilization by older low-income Medicare beneficiaries

OBJECTIVE

To examine indirect spillover effects of Affordable Care Act (ACA) Medicaid expansions to working-age adults on health care coverage, spending, and utilization by older low-income Medicare beneficiaries.

DATA SOURCES

2010-2018 Health and Retirement Study survey data linked to annual Medicare beneficiary summary files.

STUDY DESIGN

We estimated individual-level difference-in-differences models of total spending for inpatient, institutional outpatient, physician/professional provider services; inpatient stays, outpatient visits, physician visits; and Medicaid and Part A and B Medicare coverage. We compared changes in outcomes before and after Medicaid expansion in expansion versus nonexpansion states.

DATA COLLECTION/EXTRACTION METHODS

The sample included low-income respondents aged 69 and older with linked Medicare data, enrolled in full-year traditional Medicare, and residing in the community.

PRINCIPAL FINDINGS

ACA Medicaid expansion was associated with a 9.8 percentage point increase in Medicaid coverage (95% CI: 0.020-0.176), a 4.4 percentage point increase in having any institutional outpatient spending (95% CI: 0.005-0.083), and a positive but statistically insignificant 2.4 percentage point change in Part B enrollment (95% CI: -0.003 to 0.050, p = 0.079).

CONCLUSIONS

ACA Medicaid expansion was associated with more institutional outpatient spending among older low-income Medicare beneficiaries. Increased care costs should be weighed against potential benefits from increased realized access to care.

Improving Identification of Medicaid Eligible Community-Dwelling Older Adults in Major Household Surveys with Limited Income or Asset Information

Analysis of public policy affecting dual eligibles requires accurate identification of survey respondents eligible for both Medicare and Medicaid. Doing so for Medicaid is particularly challenging given the complex eligibility rules tied to income and assets. In this paper we provide guidance on how to best identify eligible respondents in household surveys that have limited income or asset information, such as the National Health Interview Survey (NHIS), American Community Survey (ACS), Current Population Survey (CPS), and Medical Expenditure Panel Survey (MEPS). We show how two types of errors-false negative and false positive errors-are impacted by incorporating limited income or asset information, relative to the commonly-used approach of solely comparing total income to the income threshold. With the 2018 Health and Retirement Study (HRS), which has detailed income and asset information, we mimic the income and asset information available in those other household surveys and quantify how errors change when imposing income or asset tests with limited information. We show that incorporating all available income and asset data results in the lowest number of errors and the lowest overall error rates. We recommend that researchers adjust income and impose the asset test to the fullest extent possible when imputing Medicaid eligibility for Medicare enrollees.

Examining Medicaid Participation and Medicaid Entry Among Senior Medicare Beneficiaries With Linked Administrative and Survey Data

Because Medicare beneficiaries can qualify for Medicaid through several pathways, duals who newly enroll in Medicaid may have experienced various financial and/or health changes that impact their Medicaid eligibility. Alternatively, new enrollment could reflect changes in awareness of the program among those previously eligible. Using monthly enrollment data linked to Health and Retirement Study survey data, we examine financial and health changes that occur around the time new Medicaid participants enter the program, and we compare those with changes experienced by both those continuously enrolled in Medicaid and those not enrolled. We find that Medicaid entry is often timed with a marked increase in out-of-pocket medical expenses, a substantial decrease in assets for some, and increases in activities of daily living (ADL) limitations. We also observe financial changes among persons continuously enrolled in Medicaid. Our results inform discussions about Medicaid eligibility policies and potential gaps in the protection that Medicaid offers from financial risk.

The Impact of Recent State and Local Minimum Wage Increases on Nursing Facility Employment

Various U.S. states and municipalities raised their mandated minimum wages between 2017 and 2019. In some areas, minimum wages became high enough to bind for more professional workers, such as lower paid staff at nursing facilities. We add to the small prior literature on the effects of minimum wages on nursing facility staffing using novel establishment-level data on daily hours worked; these data allow us to examine changes in staffing hours along margins previously unexplored in the minimum wage literature. We find no evidence that minimum wage increases reduced hours worked among lower-paid nurses in nursing facilities. In contrast, we find that increases in state and local minimum wages increased hours worked per resident day by nursing assistants; increases occurred for the average of all days throughout the month and on weekend days. We also find that a higher minimum wage increased the share of days in the month that facilities meet at least 75% of the minimum recommended levels of staffing for nursing assistants. These results lessen concerns that minimum wage hikes may reduce the quality of resident care at nursing facilities.

Differences In Care Between Special Needs Plans And Other Medicare Coverage For Dual Eligibles

Policy makers are pursuing strategies to integrate Medicare and Medicaid coverage for people enrolled in both programs, who are known as dual eligibles. Dual Eligible Special Needs Plans (D-SNPs) are Medicare Advantage plans that exclusively serve this population, with several features intended to enhance care and facilitate integration with Medicaid. This study compared access to, use of, and satisfaction with care among dual eligibles enrolled in D-SNPs versus those enrolled in two other forms of Medicare coverage: other Medicare Advantage (MA) plans not exclusively serving dual eligibles and traditional Medicare. Compared with those in traditional Medicare, dual eligibles generally reported greater access to care, preventive service use, and satisfaction with care in D-SNPs. However, we found fewer differences in these outcomes among dual eligibles in D-SNPs versus other MA plans. Compared with non-Hispanic White dual eligibles, dual eligibles of color (for example, those identifying as Black or Hispanic) were less likely to report receiving better care in D-SNPs versus other Medicare coverage. These findings suggest that D-SNPs altogether have not provided consistently superior or more equitable care, and they highlight areas where federal and state policy could strengthen incentives for D-SNPs to improve care.

Association of Medicaid Expansion With Medicaid Enrollment and Health Care Use Among Older Adults With Low Income and Chronic Condition Limitations

Question

Was the expansion of Medicaid to working-age adults under the Patient Protection and Affordable Care Act (ACA) associated with changes in Medicaid enrollment and health care use among older adults with low income and chronic condition limitations?

Findings

In this cross-sectional study of 7153 US adults 65 years or older with low income, ACA Medicaid expansion was associated with significant increases in the likelihood of Medicaid enrollment and outpatient health care use among those with chronic condition limitations. No associations were found between ACA Medicaid expansion and Medicaid enrollment and health care use among those without such limitations.

Meaning

In this study, expansion of Medicaid to working-age adults was associated with increased Medicaid enrollment and outpatient health care use among older adults with low income and chronic condition limitations who were enrolled in Medicare.

Importance

Medicaid is an important source of supplemental coverage for older Medicare beneficiaries with low income. Research has shown that Medicaid expansion under the Patient Protection and Affordable Care Act (ACA) was associated with increased Medicaid coverage for previously eligible older adults with low income, but there has been little research on whether their health care use increased or whether such changes differed by beneficiaries’ health status.

Objective

To assess whether the ACA Medicaid expansion to working-age adults was associated with increased Medicaid enrollment and health care use among older adults with low income with and without chronic condition limitations.

Design, Setting, and Participants

This cross-sectional study used data from the National Health Interview Survey from 2010 to 2017 for adults 65 years or older with low income (≤100% of the federal poverty level). Data were analyzed from November 2020 to March 2022.

Exposure

Residence in a state with Medicaid expansion for working-age adults.

Main Outcomes and Measures

The main outcomes were Medicaid coverage and health care use, measured by physician office visits and inpatient hospital care. Survey weights were used in calculating descriptive statistics and regression estimates. In multivariate analysis, difference-in-differences models were used to compare changes in outcomes over time between respondents in Medicaid expansion states and respondents in nonexpansion states.

Results

Of 21 859 adults included in the study, 7153 had chronic condition limitations (4983 [70.1%] female; mean [SD] age, 76.0 [0.1] years) and 14 706 did not have chronic condition limitations (9609 [66.3%] female; mean [SD] age, 74.85 [0.08] years). Of those with chronic condition limitations, 2707 (36.7%) were enrolled in Medicaid, 2816 (39.4%) had an office visit in the past 2 weeks, and 2152 (30.7%) used inpatient hospital care in the past year. Medicaid expansion was associated with differential increases in the likelihood of having Medicaid (4.92 percentage points; 95% CI, 0.25-9.60 percentage points; P = .04) and having an office visit in the past 2 weeks (5.31 percentage points; 95% CI, 0.10-10.51 percentage points; P = .046) compared with nonexpansion. There were no differential changes between expansion and nonexpansion states in receipt of inpatient hospital care (−0.62 percentage points; 95% CI, −5.39 to 4.14 percentage points; P = .79). Among adults without chronic condition limitations, 3159 (19.8%) were enrolled in Medicaid, and no differential changes between expansion and nonexpansion states in Medicaid enrollment (−0.24 percentage points; 95% CI, −3.06 to 2.57 percentage points; P = .86) or health care use were found.

Conclusions and Relevance

In this cross-sectional study, ACA Medicaid expansion for working-age adults was associated with increased Medicaid enrollment and outpatient health care use among older adults with low income and chronic condition limitations who were dually eligible for Medicare and Medicaid.

Effects of a Medicaid dental coverage 'cliff' on dental care access among low-income Medicare beneficiaries

OBJECTIVE

To evaluate how an abrupt drop-off, or "cliff," in Medicaid dental coverage affects access to dental care among low-income Medicare beneficiaries. Medicaid is an important source of dental insurance for low-income Medicare beneficiaries, but beneficiaries whose incomes slightly exceed eligibility thresholds for Medicaid have fewer affordable options for dental coverage, resulting in a dental coverage cliff above these thresholds.

DATA SOURCE

Medicare Current Beneficiary Surveys (MCBS) from 2016-2019.

STUDY DESIGN

We used a regression discontinuity design to evaluate effects of this dental coverage cliff. This study design exploited an abrupt difference in Medicaid coverage above income eligibility thresholds in the Medicaid program for elderly and disabled populations.

DATA COLLECTION

The study included low-income community-dwelling Medicare beneficiaries surveyed in the MCBS whose incomes, measured in percentage points of the federal poverty level, were within ±75 percentage points of state-specific Medicaid income eligibility thresholds (n=7,508 respondent-years, which when weighted represented 26,776,719 beneficiary-years).

PRINCIPAL FINDINGS

Medicare beneficiaries whose income exceeded Medicaid eligibility thresholds were 5.0 percentage points more likely to report difficulty accessing dental care due to cost concerns or a lack of insurance than beneficiaries below the thresholds (95% CI: 0.2, 9.8; P=0.04)-a one-third increase over the proportion reporting difficulty below the thresholds (15.0%).

CONCLUSIONS

A Medicaid dental coverage cliff exacerbates barriers to dental care access among low-income Medicare beneficiaries. Expanding dental coverage for Medicare beneficiaries, particularly those who are ineligible for Medicaid, could alleviate barriers to dental care access that result from the lack of comprehensive dental coverage in Medicare.

Increasing Medicaid's Stagnant Asset Test For People Eligible For Medicare And Medicaid Will Help Vulnerable Seniors

Low-income Medicare beneficiaries rely on Medicaid for supplemental coverage but must meet income and asset tests to qualify. We examined states' income and asset tests for full-benefit Medicaid during the period 2006-18 and examined how alternative asset tests would affect eligibility for community-dwelling Medicare beneficiaries ages sixty-five and older. Most states have not updated the dollar limit of Medicaid's asset test since 1989, making the asset test increasingly restrictive in inflation-adjusted terms. We estimated that increasing Medicaid's asset limit by the Consumer Price Index, to Medicare Savings Program levels, or to $10,000 for individuals and $20,000 for couples would increase Medicaid eligibility by 1.7 percent, 4.4 percent, and 7.5 percent, respectively. Simplifying Medicaid's asset test to focus only on certain high-value assets would increase eligibility by 20.5 percent. Increasing asset limits would lessen restrictions on Medicaid eligibility that arise from stagnant asset tests, broadening eligibility for certain low-income Medicare beneficiaries and allowing them to retain higher, yet still modest, savings.

Misclassification of Medicaid Participation by Dual Eligibles: Evidence From the Medicare Current Beneficiary Survey

Previous studies show that survey-based reports of Medicaid participation are measured with error, but no prior study has examined measurement error in an important segment of the Medicaid population-low-income adults enrolled in Medicare. Using the Medicare Current Beneficiary Survey, we examine whether respondent self-reports of Medicaid enrollment match administrative records and present several key findings. First, among low-income Medicare beneficiaries, the false negative rate is 11.5% when the self-report is interpreted as full Medicaid and 3.7% when the self-report is interpreted as full or partial Medicaid. Second, the likelihood of a false negative report is systematically associated with respondent traits. Third, systematic measurement error results in biased coefficient estimates in models of Medicaid participation defined from self-reports, and the bias is more significant when the researcher interprets self-reports as full Medicaid coverage only. Researchers should use caution when interpreting survey reports as pertaining to full Medicaid coverage only.

Welcome Mats and On-Ramps for Older Adults: The Impact of the Affordable Care Act's Medicaid Expansions on Dual Enrollment in Medicare and Medicaid

For many low-income Medicare beneficiaries, Medicaid provides important supplemental insurance that covers out-of-pocket costs and additional benefits. We examine whether Medicaid participation by low-income adults age 65 and up increased as a result of Medicaid expansions to working-age adults under the Affordable Care Act (ACA). Previous literature documents so-called "welcome mat" effects in other populations but has not explicitly studied older persons dually eligible for Medicare and Medicaid. We extend this literature by estimating models of Medicaid participation among persons age 65 and up using American Community Survey data from 2010 to 2017 and state variation in ACA Medicaid expansions. We find that Medicaid expansions to working-age adults increased Medicaid participation among low-income older adults by 1.8 percentage points (4.4 percent). We also find evidence of an "on-ramp" effect; that is, low-income Medicare beneficiaries residing in expansion states who were young enough to gain coverage under the 2014 ACA Medicaid expansions before aging into Medicare were 4 percentage points (9.5 percent) more likely to have dual Medicaid coverage relative to similar individuals who either turned 65 before the 2014 expansions or resided in non-expansion states. This on-ramp effect is an important mechanism behind welcome mat effects among some older adults.

Do financial incentives matter? Effects of Medicare price shocks on skilled nursing facility care

Skilled nursing facility (SNF) spending has been one of the fastest growing categories of Medicare spending over the past few decades, and reductions in SNF payments are often recommended as part of Medicare cost containment efforts. Using a quasi-experiment resulting from a policy-driven and facility-specific Medicare payment change, we provide new evidence on how Medicare payment changes affect the amount of SNF care provided to Medicare patients. Specifically, we examine a one-time, plausibly exogenous change in the hospital wage index, an area-level adjustment to SNF payments that affected the majority of SNFs nationwide. Using a panel dataset of SNFs, we model the effects of these payment changes on more than 12,000 SNFs across the United States. We find that increases in Medicare payment rates to SNFs increased the total number of Medicare resident days at SNFs. Specifically, a 5% payment increase raised Medicare resident days by 2.33% at facilities with a 10% Medicare share relative to 0%. Further, the effects were asymmetric: Although Medicare payment increases affected Medicare days, payment decreases did not. Our results have important implications for policies that alter the Medicare base payment rates to SNFs and other health care providers.

State variation in the characteristics of Medicare-Medicaid dual enrollees: Implications for risk adjustment

OBJECTIVE

To examine between-state differences in the socioeconomic and health characteristics of Medicare beneficiaries dually enrolled in Medicaid, focusing on characteristics not observable to or used by policy makers for risk adjustment.

DATA SOURCE

2010-2013 Medicare Current Beneficiary Survey.

STUDY DESIGN

Retrospective analyses of survey-reported health and socioeconomic status (SES) measures among low-income Medicare beneficiaries and low-income dual enrollees. We used hierarchical linear regression models with state random effects to estimate the between-state variation in respondent characteristics and linear models to compare the characteristics of dual enrollees by state Medicaid policies.

PRINCIPAL FINDINGS

Between-state differences in health and socioeconomic risk among low-income Medicare beneficiaries, as measured by the coefficient of variation, ranged from 17.5 percent for an index of socioeconomic risk to 20.3 percent for an index of health risk. Between-state differences were comparable among the subset of low-income beneficiaries dually enrolled in Medicare and Medicaid. Dual enrollees with incomes below the Federal Poverty Level were in better health and had higher SES in states that offered Medicaid to individuals with relatively higher incomes. Duals' average incomes were higher in states with Medically Needy programs.

CONCLUSIONS

Characteristics of dual enrollees differ substantially across states, reflecting differences in states' low-income Medicare populations and Medicaid policies. Risk-adjustment methods using dual enrollment to proxy for poor health and low SES should account for this state-level heterogeneity.

Racial and Ethnic Differences in Medicaid Acceptance by Primary Care Physicians: A Geospatial Analysis

Physician acceptance is an important dimension of access to care, especially for Medicaid patients. We constructed two new measures to quantify primary care physician (PCP) acceptance of Medicaid patients using geocoded Virginia physician addresses and population data and geospatial methods. For each Census block group, we measured the shares of "accessible PCPs" accepting any Medicaid patients or new Medicaid patients. Accessible PCPs were defined as those located within 30-minute travel from patient locations and patient locations were proxied by Census block group geographic centroids. We found that the shares of accessible PCPs accepting Medicaid varied within Virginia, and were significantly lower in urban communities where larger fractions of the population were Hispanic, even controlling for unobserved market-level traits associated with Medicaid acceptance. Policy makers and Medicaid program officials should continue to improve nonfinancial access to primary care, especially by addressing access barriers in communities with high shares of minority residents.

Defining Primary Care Shortage Areas: Do GIS-based Measures Yield Different Results?

PURPOSE

To examine whether geographic information systems (GIS)-based physician-to-population ratios (PPRs) yield determinations of geographic primary care shortage areas that differ from those based on bounded-area PPRs like those used in the Health Professional Shortage Area (HPSA) designation process.

METHODS

We used geocoded data on primary care physician (PCP) locations and census block population counts from 1 US state to construct 2 shortage area indicators. The first is a bounded-area shortage indicator defined without GIS methods; the second is a GIS-based measure that measures the populations' spatial proximity to PCP locations. We examined agreement and disagreement between bounded shortage areas and GIS-based shortage areas.

FINDINGS

Bounded shortage area indicators and GIS-based shortage area indicators agree for the census blocks where the vast majority of our study populations reside. Specifically, 95% and 98% of the populations in our full and urban samples, respectively, reside in census blocks where the 2 indicators agree. Although agreement is generally high in rural areas (ie, 87% of the rural population reside in census blocks where the 2 indicators agree), agreement is significantly lower compared to urban areas. One source of disagreement suggests that bounded-area measures may "overlook" some shortages in rural areas; however, other aspects of the HPSA designation process likely mitigate this concern. Another source of disagreement arises from the border-crossing problem, and it is more prevalent.

CONCLUSIONS

The GIS-based PPRs we employed would yield shortage area determinations that are similar to those based on bounded-area PPRs defined for Primary Care Service Areas. Disagreement rates were lower than previous studies have found.

Do Avoidable Hospitalization Rates among Older Adults Differ by Geographic Access to Primary Care Physicians?

OBJECTIVE

To investigate the association between older adults' potentially avoidable hospitalization rates and both a geographic measure of primary care physician (PCP) access and a standard bounded-area measure of PCP access.

DATA SOURCES

State physician licensure data from the Virginia Board of Medicine. Patient-level hospital discharge data from Virginia Health Information. Area-level data from the American Community Survey and the Area Health Resources Files. Virginia Information Technologies Agency road network data. US Census Bureau TIGER/Line boundary files.

STUDY DESIGN

We use enhanced two-step floating catchment area methods to calculate geographic PCP accessibility for each ZIP Code Tabulation Area in Virginia. We use spatial regression techniques to model potentially avoidable hospitalization rates.

DATA COLLECTION/EXTRACTION

Geographic accessibility was calculated using ArcGIS. Physician locations were geocoded using TAMU GeoServices and ArcGIS.

PRINCIPAL FINDINGS

Increased geographic access to PCPs is associated with lower rates of potentially avoidable hospitalization among older adults. This association is robust, allowing for spatial spillovers in spatial lag models.

CONCLUSIONS

Compared to bounded-area density measures, unbounded geographic accessibility measures provide more robust evidence that avoidable hospitalization rates are lower in areas with more PCPs per person. Results from our spatial lag models reveal the presence of positive spatial spillovers.

The impact of adolescent exposure to medical marijuana laws on high school completion, college enrollment and college degree completion

BACKGROUND

There is concern that medical marijuana laws (MMLs) could negatively affect adolescents. To better understand these policies, we assess how adolescent exposure to MMLs is related to educational attainment.

METHODS

Data from the 2000 Census and 2001-2014 American Community Surveys were restricted to individuals who were of high school age (14-18) between 1990 and 2012 (n=5,483,715). MML exposure was coded as: (i) a dichotomous "any MML" indicator, and (ii) number of years of high school age exposure. We used logistic regression to model whether MMLs affected: (a) completing high school by age 19; (b) beginning college, irrespective of completion; and (c) obtaining any degree after beginning college. A similar dataset based on the Youth Risk Behavior Survey (YRBS) was also constructed for confirmatory analyses assessing marijuana use.

RESULTS

MMLs were associated with a 0.40 percentage point increase in the probability of not earning a high school diploma or GED after completing the 12th grade (from 3.99% to 4.39%). High school MML exposure was also associated with a 1.84 and 0.85 percentage point increase in the probability of college non-enrollment and degree non-completion, respectively (from 31.12% to 32.96% and 45.30% to 46.15%, respectively). Years of MML exposure exhibited a consistent dose response relationship for all outcomes. MMLs were also associated with 0.85 percentage point increase in daily marijuana use among 12th graders (up from 1.26%).

CONCLUSIONS

Medical marijuana law exposure between age 14 to 18 likely has a delayed effect on use and education that persists over time.

Medicare Payment and Hospital Provision of Outpatient Care to the Uninsured

OBJECTIVE

To describe the amount of hospital outpatient care provided to the uninsured and its association with Medicare payment rate cuts following the implementation of Medicare's Outpatient Prospective Payment System.

DATA SOURCES/STUDY SETTING

We use hospital outpatient discharge records from Florida from 1997 through 2008.

STUDY DESIGN

We estimate multivariate regression models of hospital outpatient care provided to the uninsured in separate samples of nonprofit and for-profit hospitals.

PRINCIPAL FINDINGS

Hospital outpatient departments provide significant amounts of care to the uninsured. As Medicare payment rates fall, total charges and the share of charges for outpatient visits by the uninsured decrease at nonprofit hospitals. At for-profit hospitals, the share of outpatient care provided to uninsured patients increases, but there is no significant change in the number of uninsured discharges.

CONCLUSIONS

Nonprofit and for-profit hospitals respond differently to reductions in Medicare payments; thus, studies of the impact of legislated Medicare payment cuts on care of the uninsured should account for differences in hospital ownership in communities. Given that outpatient care to the uninsured includes preventive and diagnostic care procedures, reductions in this care following payment cuts may adversely affect long-run health and health care costs in communities dominated by nonprofit hospitals.

Recession depression: mental health effects of the 2008 stock market crash

Do sudden, large wealth losses affect mental health? We use exogenous variation in the interview dates of the 2008 Health and Retirement Study to assess the impact of large wealth losses on mental health among older U.S. adults. We compare cross-wave changes in wealth and mental health for respondents interviewed before and after the October 2008 stock market crash. We find that the crash reduced wealth and increased feelings of depression and use of antidepressant drugs, and that these effects were largest among respondents with high levels of stock holdings prior to the crash. These results suggest that sudden wealth losses cause immediate declines in subjective measures of mental health. However, we find no evidence that wealth losses lead to increases in clinically-validated measures of depressive symptoms or indicators of depression.

State unemployment in recessions during 1991-2009 was linked to faster growth in Medicare spending

During the US recession of 2007-09, overall health care spending growth fell, but Medicare spending growth increased. Using state-level data from the period 1991-2009, we show that these divergent trends were also observed within states. Furthermore, increases in state unemployment rates were associated with higher Medicare spending per capita and increased hospital use by Medicare beneficiaries. For example, a one-percentage-point point rise in the unemployment rate was associated with a $40 (0.7 percent) increase in Medicare spending per capita. Our results suggest that economic downturns contribute to Medicare spending and use. One of many possible explanations may be that health care providers have greater capacity, inclination, and financial incentive to treat Medicare patients during recessions as a result of slackening demand from the non-Medicare population.

Do changes in hospital outpatient payments affect the setting of care?

OBJECTIVE

To examine whether decreases in Medicare outpatient payment rates under the Outpatient Prospective Payment System (OPPS) caused outpatient care to shift toward the inpatient setting.

DATA SOURCES/STUDY SETTING

Hospital inpatient and outpatient discharge files from the Florida Agency for Health Care Administration from 1997 through 2008.

STUDY DESIGN

This study focuses on inguinal hernia repair surgery, one of the most commonly performed surgical procedures in the United States. We estimate multivariate regressions of inguinal hernia surgery counts in the outpatient setting and in the inpatient setting. The key explanatory variable is the time-varying Medicare payment rate specific to the procedure and hospital. Control variables include time-varying hospital and county characteristics and hospital and year-fixed effects.

PRINCIPAL FINDINGS

Outpatient hernia surgeries fell in response to OPPS-induced rate cuts. The volume of inpatient hernia repair surgeries did not increase in response to reductions in the outpatient reimbursement rate.

CONCLUSIONS

Potential substitution from the outpatient setting to the inpatient setting does not pose a serious threat to Medicare's efforts to contain hospital outpatient costs.

Racial and ethnic disparities in the surgical treatment of acute myocardial infarction: the role of hospital and physician effects

Many studies document disparities between Blacks and Whites in the treatment of acute myocardial infarction on controlling for patient demographic factors and comorbid conditions. Other studies provide evidence of disparities between Hispanics and Whites in cardiac care. Such disparities may be explained by differences in the hospitals where minority and nonminority patients obtain treatment and by differences in the traits of physicians who treat minority and nonminority patients. We used 1997-2005 Florida hospital inpatient discharge data to estimate models of cardiac catheterization, percutaneous transluminal coronary angioplasty, and coronary artery bypass grafting in Medicare fee-for-service patients 65 years and older. Controlling for hospital fixed effects does not explain Black-White disparities in cardiac treatment but largely explains Hispanic-White disparities. Controlling for physician fixed effects accounts for some extent of the racial disparities in treatment and entirely explains the ethnic disparities in treatment.

Recessions and seniors' health, health behaviors, and healthcare use: analysis of the Medicare Current Beneficiary Survey

A number of studies report that U.S. state mortality rates, particularly for the elderly, decline during economic downturns. Further, several prior studies use microdata to show that as state unemployment rates rise, physical health improves, unhealthy behaviors decrease, and medical care use declines. We use data on elderly mortality rates and data from the Medicare Current Beneficiary Survey from a time period that encompasses the start of the Great Recession. We find that elderly mortality is countercyclical during most of the 1994-2008 period. Further, as unemployment rates rise, seniors report worse mental health and are no more likely to engage in healthier behaviors. We find suggestive evidence that inpatient utilization increases perhaps because of an increased physician willingness to accept Medicare patients. Our findings suggest that either elderly individuals respond differently to recessions than do working age adults, or that the relationship between unemployment and health has changed.

Hospital volume responses to Medicare's Outpatient Prospective Payment System: evidence from Florida

Effective in 2000, Medicare's Outpatient Prospective Payment System (OPPS) sets pre-determined reimbursement rates for hospital outpatient services, replacing the prior cost-based methods of reimbursement. Using Florida outpatient discharge data, we study the effect of OPPS on hospital outpatient volume. We find that on average Medicare rate cuts either decreased or had no significant effect on Medicare volume, but increased private fee-for-service (FFS) volume. We also find that responses vary with the hospital's "exposure" to Medicare payment changes, where exposure is measured as the baseline Medicare patient share. Compared to less exposed hospitals, highly exposed hospitals responded with larger increases in private FFS volume and with smaller decreases (in some cases, even increases) in Medicare volume when payment rates fell. Our results are consistent with provider demand inducement.

Religious participation and risky health behaviors among adolescents

Previous studies have shown that adolescent religious participation is negatively associated with risky health behaviors such as cigarette smoking, alcohol consumption, and illicit drug use. One explanation for these findings is that religion directly reduces risky behaviors because churches provide youths with moral guidance or with strong social networks that reinforce social norms. An alternative explanation is that both religious participation and risky health behaviors are driven by some common unobserved individual trait. We use data from the National Longitudinal Study of Adolescent Health and implement an instrumental variables approach to identify the effect of religious participation on smoking, binge drinking, and marijuana use. Following Gruber (2005), we use a county-level measure of religious market density as an instrument. We find that religious market density has a strong positive association with adolescent religious participation, but not with secular measures of social capital. Upon accounting for unobserved heterogeneity, we find that religious participation continues to have a significant negative effect on illicit drug use. On the contrary, the estimated effects of attendance in instrumental variables models of binge drinking and smoking are statistically imprecise.

Do cigarette taxes affect children's body mass index? The effect of household environment on health

Several recent studies demonstrate a positive effect of cigarette prices and taxes on obesity among adults, especially those who smoke. If higher cigarette costs affect smokers' weights by increasing calories consumed or increasing food expenditures, then cigarette taxes and prices may also affect obesity in children of smokers. This study examines the link between child body mass index (BMI) and obesity status and cigarette costs using data from the National Longitudinal Survey of Youth-79 (NLSY79). Controlling for various child, mother, and household characteristics as well as child-fixed effects, I find that cigarette taxes and prices increase BMI in the children of smoking mothers. Interestingly, and unlike previous research findings for adults, higher cigarette taxes do not increase the likelihood of obesity in children. These findings are consistent with a causal mechanism in which higher cigarette costs reduce smoking and increase food expenditures and consumption in the household.

Child body mass index, obesity, and proximity to fast food restaurants

Objectives. Using a sample of elementary and middle school students, we examined the associations between body mass index (BMI), obesity, and measures of the proximity of fast food and full service restaurants to students' residences. We controlled for socioeconomic status using a novel proxy measure based on housing values. Methods. We used BMI and obesity measures based on height and weight data collected as part of a school health assessment along with geocoded data on addresses of residences and food establishments. We constructed a proxy measure of socioeconomic status from public records of residential property assessments. These data were used to estimate logistic regression models of overweight and ordinary least squares models of BMI. Results. Students residing in homes with higher assessment values were significantly less likely to be obese, and had significantly lower BMIs. Upon controlling for socioeconomic status and other characteristics, the associations of BMI and obesity with proximity to food service establishments were reduced. Nonetheless, students who resided within one-tenth or one-quarter of a mile from a fast food restaurant had significantly higher values of BMI. The proximity of full service restaurants to residences did not have a significant positive association with either BMI or overweight. Conclusion. Public health efforts to limit access to fast food among nearby residents could have beneficial effects on child obesity. Public data on property value assessments may serve as useful approximations for socioeconomic status when address data are available.

Predicting health behaviors with an experimental measure of risk preference

We conduct a large-scale economics experiment paired with a survey to examine the association between individual risk preference and health-related behaviors among adults aged 18-87 years. Risk preference is measured by the lottery choice experiment designed by Holt and Laury [Holt, C.A., Laury, S.K., 2002. Risk aversion and incentive effects. The American Economic Review 92(5), 1644-1655]. Controlling for subject demographic and economic characteristics, we find that risk aversion is negatively and significantly associated with cigarette smoking, heavy drinking, being overweight or obese, and seat belt non-use. In additional specifications, we find that risk aversion is negatively and significantly associated with the likelihood a subject engaged in any of five risky behaviors and the number of risky behaviors reported.

The impact of child obesity on active parental consent in school-based survey research on healthy eating and physical activity

Previous studies have shown that active consent procedures result in sampling bias in surveys dealing with adolescent risk behaviors such as cigarette smoking and illicit drug use. To examine sampling bias from active consent procedures when the survey topic pertains to childhood obesity and associated health behaviors, the authors pair data obtained from both active and passive consent procedures. The authors find that parents of children who are overweight or at risk for being overweight are significantly less likely to give active consent. In addition, parents of children enrolled in lower grades are more reluctant to consent to participate.

State social capital and individual health status

Recent studies have found that two state-level measures of social capital, average levels of civic participation and trust, are associated with improvements in individual health status. In this study we employ these measures, together with the Putnam index of state social capital, to examine several key aspects of the relationship between state social capital and individual health. We find that for all three measures, the association with health status persists after carefully adjusting for household income and that for two measures, mistrust and the Putnam index, the size of this association warrants further attention. Using the Putnam index, we find particular support for the hypothesis that social capital has a more pronounced salutary effect for the poor. Our findings generate both support for the social capital and health hypothesis and a number of implications for future research.

Individual health status and racial minority concentration in US states and counties

OBJECTIVES

We examined whether the positive association between mortality rates and racial minority concentration documented in ecological studies would be found for health status after control for race/ethnicity, socioeconomic status, and region of residence.

METHODS

We estimated least squares and probit models using aggregate and individual health status data from the 1995, 1997, and 1999 versions of the Current Population Survey merged with data from the US Bureau of the Census regarding state- and county-level racial minority concentration.

RESULTS

Except in the case of older Whites, racial minority concentration was not associated with health status after control for individual characteristics and fixed regional factors.

CONCLUSIONS

Racial minority concentration may not be a determinant of individual health; differential migration patterns may explain the anomalous result for older Whites.

On the importance of age-adjustment methods in ecological studies of social determinants of mortality

OBJECTIVE

To illustrate the potential sensitivity of ecological associations between mortality and certain socioeconomic factors to different methods of age-adjustment.

DATA SOURCES

Secondary analysis employing state-level data from several publicly available sources. Crude and age-adjusted mortality rates for 1990 are obtained from the U.S. Centers for Disease Control. The Gini coefficient for family income and percent of persons below the federal poverty line are from the U.S. Bureau of Labor Statistics. Putnam's (2000) Social Capital Index was downloaded from http://www.bowlingalone.com; the Social Mistrust Index was calculated from responses to the General Social Survey, following the method described in Kawachi et al. (1997). All other covariates are obtained from the U.S. Census Bureau.

STUDY DESIGN

We use least squares regression to estimate the effect of several state-level socioeconomic factors on mortality rates. We examine whether these statistical associations are sensitive to the use of alternative methods of accounting for the different age composition of state populations. Following several previous studies, we present results for the case when only mortality rates are age-adjusted. We contrast these results with those obtained from regressions of crude mortality on age variables.

PRINCIPAL FINDINGS

Different age-adjustment methods can cause a change in the sign or statistical significance of the association between mortality and various socioeconomic factors. When age variables are included as regressors, we find no significant association between mortality and either income inequality, minority racial concentration, or social capital.

CONCLUSIONS

Ecological associations between certain socioeconomic factors and mortality may be extremely sensitive to different age-adjustment methods.

Is exposure to income inequality a public health concern? Lagged effects of income inequality on individual and population health

OBJECTIVE

To examine the health consequences of exposure to income inequality.

DATA SOURCES

Secondary analysis employing data from several publicly available sources. Measures of individual health status and other individual characteristics are obtained from the March Current Population Survey (CPS). State-level income inequality is measured by the Gini coefficient based on family income, as reported by the U.S. Census Bureau and Al-Samarrie and Miller (1967). State-level mortality rates are from the Vital Statistics of the United States, other state-level characteristics are from U.S. census data as reported in the Statistical Abstract of the United States.

STUDY DESIGN

We examine the effects of state-level income inequality lagged from 5 to 29 years on individual health by estimating probit models of poor/fair health status for samples of adults aged 25-74 in the 1995 through 1999 March CPS. We control for several individual characteristics, including educational attainment and household income, as well as regional fixed effects. We use multivariate regression to estimate the effects of income inequality lagged 10 and 20 years on state-level mortality rates for 1990, 1980, 1970, and 1960.

PRINCIPAL FINDINGS

Lagged income inequality is not significantly associated with individual health status after controlling for regional fixed effects. Lagged income inequality is not associated with all cause mortality, but associated with reduced mortality from cardiovascular disease and malignant neoplasms, after controlling for state fixed-effects.

CONCLUSIONS

In contrast to previous studies that fail to control for regional variations in health outcomes, we find little support for the contention that exposure to income inequality is detrimental to either individual or population health.

Duplex Scorpion primers in SNP analysis and FRET applications

Scorpions are fluorogenic PCR primers with a probe element attached at the 5'-end via a PCR stopper. They are used in real-time amplicon-specific detection of PCR products in homogeneous solution. Two different formats are possible, the 'stem-loop' format and the 'duplex' format. In both cases the probing mechanism is intramolecular. We have shown that duplex Scorpions are efficient probes in real-time PCR. They give a greater fluorescent signal than stem-loop Scorpions due to the vastly increased separation between fluorophore and quencher in the active form. We have demonstrated their use in allelic discrimination at the W1282X locus of the ABCC7 gene and shown that they can be used in assays where fluorescence resonance energy transfer is required.

Long-term care and nursing home coverage: are adult children substitutes for insurance policies?

Recent theoretical work suggests that in some cases, parents will forego the purchase of long-term care insurance and rely on child-provided care in old age. This paper uses data from the Asset and Health Dynamics survey and the Panel Study of Income Dynamics to examine whether the availability of children and other potential caregivers explains why so few elderly persons have long-term care insurance. In contrast to the notion that family members serve as substitutes for long-term care insurance, variables measuring the availability of informal caregivers have no statistically significant effect in models of insurance ownership and models of intentions to purchase insurance.

Reexamining the evidence of an ecological association between income inequality and health

Several recent studies have made the provocative claim that income inequality is an important determinant of population health. The primary evidence for this hypothesis is the repeated finding--across countries and across U.S. states--that there is an association between income inequality and aggregate health outcomes. However, most of these studies examine only a single cross section of data and employ few (or even no) control variables. We examine the relationship between income inequality and aggregate health outcomes across thirty countries over a four-decade span and across forty-eight U.S. states over five decades. In large part, our findings contradict previous claims.

Pyridoxal phosphate de-activation by pyrroline-5-carboxylic acid. Increased risk of vitamin B6 deficiency and seizures in hyperprolinemia type II

We previously identified vitamin B6 deficiency in a child presenting with seizures whose primary diagnosis was the inherited disorder hyperprolinemia type II. This is an unrecognized association, which was not explained by diet or medication. We hypothesized that pyridoxal phosphate (vitamin B6 coenzyme) was de-activated by L-Delta(1)-pyrroline-5-carboxylic acid, the major intermediate that accumulates endogenously in hyperprolinemia type II. The proposed interaction has now been investigated in vitro with high resolution 1H nuclear magnetic resonance spectroscopy and mass spectrometry at a pH of 7.4 and temperature of 310 K. Three novel adducts were identified. These were the result of a Claisen condensation (or Knoevenagel type of reaction) of the activated C-4 carbon of the pyrroline ring with the aldehyde carbon of pyridoxal phosphate. The structures of the adducts were confirmed by a combination of high performance liquid chromatography, nuclear magnetic resonance, and mass spectrometry. This interaction has not been reported before. From preliminary observations, pyrroline-5-carboxylic acid also condenses with other aromatic and aliphatic aldehydes and ketones, and this may be a previously unsuspected generic addition reaction. Pyrroline-5-carboxylic acid is thus found to be a unique endogenous vitamin antagonist. Vitamin B6 de-activation may contribute to seizures in hyperprolinemia type II, which are so far unexplained, but they may be preventable with long term vitamin B6 supplementation.

Private long-term care insurance and the asset protection motive

This research examined the role of assets in the decision to purchase insurance for long-term care using survey data from the Asset and Health Dynamics Among the Oldest Old (AHEAD) study. Previous research suggests that assets matter, but the size and direction of the effect varies. An important issue regarding the role of assets has not been explored adequately--whether the effect of assets differs between less wealthy and very wealthy individuals. A methodology to control for this type of variation is employed in this analysis. Results suggest that increases in assets have the greatest influence on the probability that less wealthy individuals own long-term care insurance, and have a negligible impact on the wealthy. This has important implications for policies designed to increase long-term care insurance ownership.

Synthesis of novel intranuclear diazasteroids

By use of the aza Diels-Alder reaction a series of aminoisoquinolines and aminoquinolines have been elaborated to provide an effective synthesis of diverse diazasteroids. In particular, representative 1,11-diaza-, 3,11-diaza-, and 4,11-diazasteroids have been synthesized from cyclopentadiene. From dihydropyran a 4,11-diaza-15-oxa-D-homosteroid has been obtained.

Constrained peptide analogues of transforming growth factor-alpha residues cysteine 21-32 are mitogenically active. Use of proline mimetics to enhance biological potency

Two proline mimetics, the enantiomers of 2-aza-bicyclo[2,2,1]heptane-3-carboxylic acid, have been incorporated in place of Pro30 into synthetic peptides based on the B-loop beta-sheet sequence of human transforming growth factor-alpha (TGF-alpha) (residues Cys21-Cys32). The peptides were further modified by inclusion of an N-terminal phenylalanine and constrained by formation of an intramolecular disulfide bond. While no mitogenic response was observed in the parental NR6 cell line, the peptides stimulated DNA synthesis in NR6/HER cells (NR6 fibroblasts transfected with the human epidermal growth factor receptor). Induction of DNA synthesis was dose dependent, with EC50 values in the range 130-330 microM; in the presence of low doses of TGF-alpha, the mitogenic effect of the peptides was additive, up to the plateau response achieved by maximal doses of TGF-alpha alone. These effects are consistent with the peptides acting via the same mechanism as TGF-alpha. Analysis of the structure of the peptides by NMR indicated that the presence of the mimetics significantly increased the propensity of the peptidyl-proline bond to adopt the cis conformation. These data confirm the role of the beta-sheet in receptor activation, and emphasize the importance of presentation of peptides in an appropriate conformation for recognition.

Endothelial cell transformation in primary biliary cirrhosis: a morphological and biochemical study

There is increasing interest in the changes of the endothelial lining of the hepatic sinusoids during the development of chronic liver disease. In this study we looked for evidence of hepatic sinusoidal endothelial cell transformation and basement membrane production in patients with primary biliary cirrhosis. Morphological transformation to vascular-type endothelial cells, as evidenced by the development VIII-related antigen, was seen at the interface between portal tracts or fibrous septae and hepatic parenchyma; the most marked changes were observed in patients with established cirrhosis. Increased immunohistochemical staining for the basement membrane components type IV collagen and laminin was also found in a similar distribution. Raised serum levels of hyaluronic acid, a glycosaminoglycan metabolized by normal hepatic endothelial cells, were found in most patients and correlated strongly with advancing histological stage. Furthermore, significant positive correlations were found between serum hyaluronic acid and serum levels of laminin and type IV collagen. The unique structure of the normal endothelial lining of the hepatic sinusoids is important in the maintenance of hepatic function. Our data show that significant changes in endothelial cell structure and function occur in primary biliary cirrhosis and appear to be a contributing factor to the progression of the disease. Further studies are needed to determine the extent and importance of these changes in other forms of chronic liver disease.

3-Methylisoxazol-5-one, an artefact from acetoacetic acid formed during urinary organic acid analysis

During the analysis of urine for organic acids for suspected metabolic disorders by solvent extraction, derivatisation and capillary gas chromatography, unaccountably large lactic acid peaks were observed in some samples containing large amounts of acetoacetic acid. Electron impact mass spectrometry showed that this was due to two unknown compounds coeluting with lactic acid. These were found to be two trimethylsilyl derivatives of 3-methylisoxazol-5-one, produced from acetoacetic acid during oximation with hydroxylamine hydrochloride, by a cyclisation reaction. Awareness of the formation of this previously unreported artefact is important to laboratories employing a similar profiling procedure.