Non-classical measurement error in instrumental variables estimation: An application to the medical care costs of obesity.

Estimates of the impact of body mass index and obesity on health and labor market outcomes often use instrumental variables estimation (IV) to mitigate bias due to endogeneity. When these studies rely on survey data that include self- or proxy-reported height and weight, there is non-classical measurement error due to the tendency of individuals to under-report their own weight. Mean reverting errors in weight do not cause IV to be asymptotically biased per se, but may result in bias if instruments are correlated with additive error in weight. We demonstrate the conditions under which IV is biased when there is non-classical measurement error and derive bounds for this bias conditional on instrument strength and the severity of mean-reverting error. We show that improvements in instrument relevance alone cannot eliminate IV bias, but reducing the correlation between weight and reporting error mitigates the bias. A solution we consider is regression calibration (RC) of endogenous variables with external validation data. In simulations, we find IV estimation paired with RC can produce consistent estimates when correctly specified. Even when RC fails to match the covariance structure of reporting error, there is still a reduction in asymptotic bias.

The effects of dental hygienist autonomy on dental care utilization.

We investigate the effects of regulations governing the practice autonomy of dental hygienists on dental care use with the 2001-2014 Medical Expenditure Panel Survey. We measure the strength of autonomy regulations by extending the Dental Hygiene Professional Practice Index to the years 2001-2014, allowing us to capture changes in regulations within states over time. Using a difference-in-differences framework applied to selected states, we find that relaxing supervision requirements to provide dental hygienists moderate autonomy results in an increase in total dental visits due to greater use of preventive dental care. However, the use of dental treatment decreases when states adopt the highest level of autonomy. Both sets of estimates increase in magnitude when we subset the sample to dental care provider shortage areas. In support of these findings, we show that dental visits shift to dental hygienists in shortage areas when states expand the scope of practice of hygienists, and that there is an increase in tasks performed by hygienists, such as cleanings and dental exams.

Do elections make you sick? Evidence from first-time voters.

Elections permit the continuance of democracy and enable economic development, but may have unintended effects on health. By applying a two-part model with regression discontinuity design to administrative health care claims, we determine that elections increased health care use during legally specified campaign periods by as much as 19% for first-time voters. Contrary to earlier studies focusing on mental health, we find higher spending on the treatment of physical health conditions, such as acute respiratory infections, gastrointestinal conditions and injuries. Levels of medical spending during campaign periods were highest in rural areas and among low-to-middle-income men. Using data on campaign spending from local elections, we identify campaign rallies as one important mechanism for the transmission of disease. Our findings provide additional rationale for policies that limit campaign spending on the grounds that it is socially wasteful.

Dental care use and other population characteristics of older Americans with self-reported chronic conditions in the health and retirement study.

OBJECTIVES: To analyze relative differences in oral health care utilization, oral health, and other population characteristics of older Americans with respect to self-reported chronic conditions in the health and retirement study. METHODS: Differences in estimated percentages of those with specific chronic conditions by selected attributes were tested for statistical significance with standardized normal Z tests and logistic regressions. All estimates were based on weighted data from 1992 to 2016 Early Release RAND HRS Longitudinal file. SE estimates for the percentages accounted for the complex sample design of the survey. RESULTS: We establish that the strength of the associations between regular use of dental care and the absence of a chronic condition is similar in magnitude to having a college education, living in a high-income family, never smoking, not having certain functional limitations, and being under 65 years of age. DISCUSSION: These cross-sectional findings establish the relative strength of relationships between dental care use, oral health status, and other population characteristics and eight diagnosed conditions. Further work beyond the scope of this paper is needed to confirm these results as either attributes of those with the disease or causal risk factors for the onset of the condition.

The role of electronic health record developers in hospital patient sharing.

OBJECTIVE: To determine whether hospital adoption of a new electronic health record (EHR) developer increases patient sharing with hospitals using the same developer. MATERIALS AND METHODS: We extracted data on patients shared with other hospitals for 3076 US nonfederal acute care hospitals from the 2011 to 2016 Centers for Medicare & Medicaid Services Physician Shared Patient Patterns database. We calculated the ratio of patients shared with hospitals outside of the focal hospital's network that use the same EHR developer as the focal hospital, and estimated difference-in-differences models to compare same-developer patient sharing among hospitals that switched to a new developer with those that did not switch developer. RESULTS: Switching to a new EHR developer increased the ratio of patients shared with other hospitals having the same EHR developer by 4.1-19.3%, depending on model specification. The magnitude of this effect varied by EHR developer and was increasing in developer market share. DISCUSSION: Consolidation in the EHR industry has led to higher patient sharing among hospitals with the same EHR developer. Contributing factors could include the growth of developer-based health information exchanges, customizable referral management systems, and provider preferences for easy and reliable data exchange. However, hospital transfers that are significantly influenced by EHR developer could lead to poor patient-provider matches. CONCLUSION: Hospitals' choice of EHR developer impacts the flow of patients across hospitals, which could have both desirable and undesirable effects on patient care. Future research should investigate whether health outcomes decline with greater same-developer patient sharing.

COVID-19 prevention, air pollution and transportation patterns in the absence of a lockdown.

Recent studies demonstrate that air quality improved during the coronavirus pandemic due to the imposition of social lockdowns. We investigate the impact of COVID-19 on air pollution in the two largest cities in Taiwan, which were not subject to economic or mobility restrictions. Using a difference-in-differences approach and real-time data on air quality and transportation, we estimate that anthropogenic air pollution from local sources increased during working days and decreased during non-working days during the COVID-19 pandemic. This led to a 3-7 percent increase in CO, O3, SO2, PM10 and PM2.5. We demonstrate that the increase in air pollution resulted from a shift in preferred mode of travel away from public transportation and towards personal motor vehicles during working days. In particular, metro and shared bicycle usage decreased between 8 and 18 percent, on average, while automobile and scooter use increased between 11 and 21 percent during working days. Similar COVID-19 prevention behaviors in regions or countries emerging from lockdowns could likewise result in an increase in air pollution. Taking action to reduce the transmissibility of COVID-19 on metro cars, trains and buses could help policymakers limit the substitution of personal motor vehicles for public transit, and mitigate increases in air pollution when lifting mobility restrictions.

Job Absenteeism Costs of Obesity in the United States: National and State-Level Estimates.

OBJECTIVE: To estimate the causal effect of obesity on job absenteeism and the associated lost productivity in the United States, both nationwide and by state. METHODS: We conducted a retrospective pooled cross-sectional analysis using the 2001 to 2016 Medical Expenditure Panel Survey and estimated two-part models of instrumental variables. RESULTS: Obesity, relative to normal weight, raises job absenteeism due to injury or illness by 3.0 days per year (128%). Annual productivity loss due to obesity ranges from $271 to $542 (lower/upper bound) per employee with obesity, with national productivity losses ranging from $13.4 to $26.8 billion in 2016. Trends in state-level estimates mirror those at the national level, varying across states. CONCLUSIONS: Obesity significantly raises job absenteeism. Reductions in job absenteeism should be included when calculating the cost-effectiveness of interventions to prevent or reduce obesity among employed adults.

Direct medical costs of obesity in the United States and the most populous states.

BACKGROUND: After a dramatic increase in prevalence over several decades, obesity has become a major public health crisis in the United States. Research to date has consistently demonstrated a correlation between obesity and higher medical costs for a variety of U.S. subpopulations and specific categories of care. However, by examining associations rather than causal effects, previous studies likely underestimated the effect of obesity on medical expenditures. OBJECTIVE: To estimate the causal effect of obesity on direct medical care costs at the national and state levels. METHODS: This study is a pooled cross-sectional analysis of retrospective data from the 2001-2016 Medical Expenditure Panel Surveys. Adults aged 20-65 years with a biological child living in the household were included in the study sample. Primary outcomes were individual-level medical expenditures due to obesity, overall, as well as separately by type of payer and category of medical care. Results were reported at the national level and separately for the 20 most populous states. The expenditure estimates were obtained from 2-part models of instrumental variables in which the respondent's body mass index (BMI) was instrumented using the BMI of their biological child. RESULTS: Adults with obesity in the United States compared with those with normal weight experienced higher annual medical care costs by $2,505 or 100%, with costs increasing significantly with class of obesity, from 68.4% for class 1 to 233.6% for class 3. The effects of obesity raised costs in every category of care: inpatient, outpatient, and prescription drugs. Increases in medical expenditures due to obesity were higher for adults covered by public health insurance programs ($2,868) than for those having private health insurance ($2,058). In 2016, the aggregate medical cost due to obesity among adults in the United States was $260.6 billion. The increase in individual-level expenditures due to obesity varied considerably by state (e.g., 24.0% in Florida, 66.4% in New York, and 104.9% in Texas). CONCLUSIONS: The 2-part models of instrumental variables, which estimate the causal effects of obesity on direct medical costs, showed that the effect of obesity is greater than suggested by previous studies, which estimated only correlations. Much of the aggregate national cost of obesity-$260.6 billion-represents external costs, providing a rationale for interventions to prevent and reduce obesity. DISCLOSURES: Novo Nordisk financed the development of the study design, analysis, and interpretation of data, as well as writing support of the manuscript. Cawley, Biener, and Meyerhoefer received financial support from Novo Nordisk to conduct the research study on which this manuscript is based. Smolarz and Ramasamy are employees of Novo Nordisk. Ding and Zvenyach have no conflicts to declare. Our research has been presented as a poster at the 2020 Academy Health Annual Research Meeting (Virtual), July 28-August 6, 2020.

The effects of paid sick leave on worker absenteeism and health care utilization.

We estimate the short-term effects of paid sick leave on worker absenteeism and health care utilization in the United States using data from the 2000-2013 Medical Expenditure Panel Survey. We use both parametric and matching-based difference-in-differences methods to account for nonrandom selection into jobs that offer paid sick leave and estimate the treatment effect separately for workers who gained and lost sick leave benefits. We find consistent evidence of increased absenteeism among female workers who gained paid sick leave but not for other groups. Estimates for office-based visits are mostly statistically insignificant and may not have a causal interpretation due to preexisting trends.

The medical care costs of obesity and severe obesity in youth: An instrumental variables approach.

This paper is the first to use the method of instrumental variables to estimate the impact of obesity and severe obesity in youth. on U.S. medical care costs. We examine data from the Medical Expenditure Panel Survey for 2001-2015 and instrument for child BMI using the BMI of the child's biological mother. Instrumental variables estimates indicate that obesity in youth raises annual medical care costs by $907 (in 2015 dollars) or 92%, which is considerably higher than previous estimates of the association of youth obesity with medical costs. We find that obesity in youth significantly raises costs in all major categories of medical care: outpatient doctor visits, inpatient hospital stays, and prescription drugs. The costs of youth obesity are borne almost entirely by third-party payers, which is consistent with substantial externalities of youth obesity, which in turn represents an economic rationale for government intervention.

The effects of Medicaid expansion on labor market outcomes: Evidence from border counties.

This paper provides new empirical evidence on the employment and earning effects of the recent Medicaid expansion. Unlike most existing studies that use a conventional state and year fixed effects approach, our main identification strategy is based on the comparison of employment and wages in contiguous county-pairs in neighboring states (i.e., border counties) with different Medicaid expansion status. Using the 2008-2016 Quarterly Census of Employment and Wages, we estimate a set of distributed lag models in order to examine the dynamic effects of Medicaid expansion. Results from our preferred specification suggest a statistically significant decrease in total employment of 1.2% 1 year after the expansion of Medicaid. This translates into a 37% decrease in employment among newly eligible Medicaid enrollees under the strong assumption that Medicaid coverage did not crowd out private insurance coverage. We also find that this disemployment effect is transitory: 2 years after the Medicaid expansion employment returns to preexpansion levels. We do not find any statistically significant effect of the Medicaid expansion on wages at any point.

Does covering routine dental care for the Medicare population produce cost savings in Medicare? A preliminary 2-year analysis.

OBJECTIVES: We estimated the association between the use of preventive dental care and medical use and expense for older persons over a 2-year period to determine if a Medicare dental benefit for routine care could result in potential cost savings in Medicare. METHODS: We relied on 2008-2014 Medical Expenditure Panel Survey data to estimate separate logistic and lognormal ordinary least squares regressions to analyze the influence of year 1 preventive dental care on either year 1 or year 2 use and expenses for total health care, office-based care, outpatient care, inpatient stays, emergency department visits, and prescription drugs. RESULTS: Our findings provide evidence over a 2-year period that a Medicare dental benefit for routine care could produce an increase in office-based visits and expense. We also found that older persons currently using routine dental care have healthier lifestyles and greater access to care and use of preventive medical care than current nonusers. CONCLUSION: Our results affirm the need for a longer-term study to provide any conclusive evidence as to the ultimate impact of a Medicare dental benefit on other health care use and expenses.

The demand for preventive and restorative dental services among older adults.

Many older Americans have poor access to dental care, resulting in a high prevalence of oral health problems. Because traditional Medicare does not include dental care benefits, only older Americans who are employed, have post-retirement dental benefits or spousal coverage, or enroll in certain Medicare Advantage plans are able to obtain dental care coverage. We seek to determine the extent to which poor access to dental insurance and high out-of-pocket costs affect dental service use by the elderly. Using the 2007-2015 Medical Expenditure Panel Survey and supplemental data on dental care prices, we estimate a demand system for preventive dental services and basic and major restorative services. Selection into dental and medical insurance is addressed using a correlated random effects panel data specification. Consistent with prior studies of the nonelderly population, dental service use was not sensitive to out-of-pocket prices. However, private dental insurance increased preventive service use by 25%, and dental coverage through Medicaid increased basic and major service use by 23% and 36%, respectively. The use of services was more responsive to dental insurance for women than men. These estimates suggest that a Medicare dental benefit could significantly increase dental service use by older Americans.

Inter-brand competition in the convenience store industry, store density and healthcare utilization.

We investigate the impact of access to convenience stores and competition between convenience store chains on the use of medical care in Taiwan. Using insurance claims from 0.85 million individuals and administrative data on store sales, we find that greater store density and more inter-brand competition reduced expenditures on outpatient medical services and prescription drugs. In support of these findings, we demonstrate that convenience store competition was associated with greater consumption of healthy foods and lower obesity rates. Our estimates suggest that the rise in convenience store competition from 2002 to 2012 reduced outpatient expenditures in Taiwan by 0.44 percent and prescription drug expenditures by 0.85 percent.

Provider and patient satisfaction with the integration of ambulatory and hospital EHR systems.

Objective: The installation of EHR systems can disrupt operations at clinical practice sites, but also lead to improvements in information availability. We examined how the installation of an ambulatory EHR at OB/GYN practices and its subsequent interface with an inpatient perinatal EHR affected providers' satisfaction with the transmission of clinical information and patients' ratings of their care experience. Methods: We collected data on provider satisfaction through 4 survey rounds during the phased implementation of the EHR. Data on patient satisfaction were drawn from Press Ganey surveys issued by the healthcare network through a standard process. Using multivariable models, we determined how provider satisfaction with information transmission and patient satisfaction with their care experience changed as the EHR system allowed greater information flow between OB/GYN practices and the hospital. Results: Outpatient OB/GYN providers became more satisfied with their access to information from the inpatient perinatal triage unit once system capabilities included automatic data flow from triage back to the OB/GYN offices. Yet physicians were generally less satisfied with how the EHR affected their work processes than other clinical and non-clinical staff. Patient satisfaction dropped after initial EHR installation, and we find no evidence of increased satisfaction linked to system integration. Conclusions: Dissatisfaction of providers with an EHR system and difficulties incorporating EHR technology into patient care may negatively impact patient satisfaction. Care must be taken during EHR implementations to maintain good communication with patients while satisfying documentation requirements.

The health implications of unconventional natural gas development in Pennsylvania.

We investigate the health impacts of unconventional natural gas development of Marcellus shale in Pennsylvania between 2001 and 2013 by merging well permit data from the Pennsylvania Department of Environmental Protection with a database of all inpatient hospital admissions. After comparing changes in hospitalization rates over time for air pollution-sensitive diseases in counties with unconventional gas wells to changes in hospitalization rates in nonwell counties, we find a significant association between shale gas development and hospitalizations for pneumonia among the elderly, which is consistent with higher levels of air pollution resulting from unconventional natural gas development. We note that the lack of any detectable impact of shale gas development on younger populations may be due to unobserved factors contemporaneous with drilling, such as migration.

The Impact of Obesity on Medical Care Costs and Labor Market Outcomes in the US.

BACKGROUND: The prevalence of obesity has risen dramatically in most countries of the world, and the economic consequences of obesity are not well understood. METHODS: We analyzed data from the Medical Expenditure Panel Survey (MEPS) for 2001-2015 and estimated the percentage of healthcare costs that were associated with adult obesity, both for the US as a whole and for the most populous states. We also reviewed the literature on the impact of obesity on economic outcomes such as medical care costs, employment, and wages. RESULTS: The percent of US national medical expenditures devoted to treating obesity-related illness in adults rose from 6.13% in 2001 to 7.91% in 2015, an increase of 29%. Substantial differences existed across states; in 2015, some states (AZ, CA, FL, NY) devoted 5%-6% of medical expenditures to obesity, whereas others (NC, OH, WI) spent >12% of all healthcare dollars on obesity. A review of previous literature that exploited natural experiments to estimate causal effects found that obesity raises medical care costs and lowers wages and the probability of employment. CONCLUSIONS: A substantial and rising percentage of healthcare costs are associated with obesity. This is true for the US, for individual states, for each category of expenditure, and for each type of payer. Previous literature generally found that obesity worsens economic outcomes, such as medical care costs, wages, and employment, and imposes negative external costs that may justify government intervention.

Projecting the Demand for Dental Care in 2040.

The purpose of this study was to provide a forward-thinking assessment of the underlying factors likely to impact trends in dental care demand and the need for dental providers in 2020, 2025, and beyond. Dental workforce trends and their likely impact on the need for dentists are a function of predicted dental care demand, which will in turn be determined by the size and characteristics of our population size, economic outlook, the state of public and private dental care insurance, trends in dental care delivery, professionally determined dental care need, and population health beliefs. Projecting rates of dental care utilization far into the future is difficult because projections must be made using historical data, and established trends may not persist if there is structural change in the future. Nonetheless, when structural change occurs, it does not typically affect all aspects of the economy, so there is value in describing the likely future impact of current trends. This article was written as part of the project "Advancing Dental Education in the 21st Century."

A mixed methods study of clinical information availability in obstetric triage and prenatal offices.

OBJECTIVE: To determine the effect of availability of clinical information from an integrated electronic health record system on pregnancy outcomes at the point of care. MATERIALS AND METHODS: We used provider interviews and surveys to evaluate the availability of pregnancy-related clinical information in ambulatory practices and the hospital, and applied multiple regression to determine whether greater clinical information availability is associated with improvements in pregnancy outcomes and changes in care processes. Our regression models are risk adjusted and include physician fixed effects to control for unobservable characteristics of physicians that are constant across patients and time. RESULTS: Making nonstress test results, blood pressure data, antenatal problem lists, and tubal sterilization requests from office records available to hospital-based providers is significantly associated with reductions in the likelihood of obstetric trauma and other adverse pregnancy outcomes. Better access to prenatal records also increases the probability of labor induction and decreases the probability of Cesarean section (C-section). Availability of lab test results and new diagnoses generated in the hospital at ambulatory offices is associated with fewer preterm births and low-birth-weight babies. DISCUSSION AND CONCLUSIONS: Increased availability of specific clinical information enables providers to deliver better care and improve outcomes, but some types of clinical data are more important than others. More available information does not always result from automated integration of electronic records, but rather from the availability of the source records. Providers depend upon information that they trust to be reliable, complete, consistent, and easily retrievable, even if this requires multiple interfaces.