You'll never walk alone - The effects of walkability on pregnancy behaviors and outcomes.

This study investigates the relationship between local walkability and physical activity and subsequent health outcomes among pregnant women - for whom walking is the recommended, and by far most common, form of exercise. Using an EPA measure of walkability at the county level (as well as other county-level characteristics) combined with rich individual-level data on pregnant women yields evidence that higher walkability translates into improvements in maternal and infant health outcomes as well as physical activity. Using the 2011 Natality Detail Files with geographic identifiers and controlling for the overall health of women in the community as well as the individual mother's pre-pregnancy BMI, we show that women residing in more walkable counties are less likely to experience preterm birth, low birth weight, gestational diabetes and hypertension. While one potential mechanism is through improved gestational weight gain, the evidence points to more general improvements in health as walkability does not seem to prevent excessive weight gain or macrosomic babies. Evidence that these general improvements derive at least in part from greater physical activity comes from analyses using the 2011 Behavioral Risk Factor Surveillance System, in which higher walkability translates into more physical activity among pregnant women (and also relative to their non-pregnant counterparts). Our study suggests more broadly that pregnant women's physical activity responds to factors that facilitate it and that such activity makes a difference to birth outcomes.

US Health Care Expenditures, GDP and Health Policy Reforms: Evidence from End-of-Sample Structural Break Tests.

This research investigates the over-time stability of the aggregate US healthcare expenditure (HCE)-GDP relationship, focusing on periods of healthcare reforms. The most consequential reforms-Medicaid/Medicare and the Affordable Care Act (ACA)-are challenging to study because they occur near the ends of the available data. Using annual national- and state-level data and a battery of structural break tests, we find the HCE-GDP relationship to be overwhelmingly stable. An ancillary analysis around the 2006 Massachusetts healthcare reform, which avoids the confounding effects of the Great Recession and the staggered rollout of the ACA, likewise finds no change.

The effect of tobacco policies on youth physical activity.

Our research examines the effects of tobacco policies on teenagers' physical activity. Smoking and physical activity are both strategies for weight management, and exercise may be a way to reduce some of the ill effects of smoking. These different links suggest that cigarette taxes could either increase or decrease physical activity. We explore this relationship using repeated cross-sectional 1991-2017 data from the national and state Youth Risk Behavior Surveillance System (YRBSS), combined with state-level policies and controls. Our smoking participation results confirm past work; cigarette taxes have a negative effect on smoking that has waned in recent years. The estimated effects of cigarette taxes on physical activity echo those of smoking; cigarette taxes decrease physical activity and, like smoking, these effects have waned recently. However, one likely avenue - sports participation - is unaffected. These results suggest that increased cigarette taxes lead to modest declines in teen physical activity, a finding consistent with youth using exercise to compensate for the health effects of smoking.

Sunshine, fertility and racial disparities.

This research investigates the effect of sun exposure on fertility, with a special focus on how its effects and consequences for birth outcomes may differ by race. Sun exposure is a key mechanism for obtaining Vitamin D, but this process is inhibited by skin pigmentation. Vitamin D has been linked to male and female fertility and risk of miscarriage, and Vitamin D deficiency is more prevalent among blacks than whites. Using 1989-2004 individual live births data from the Natality Detail Files, county-level, monthly conceptions are estimated as a function of monthly solar insolation, temperature and humidity, as well as month, time and location fixed effects and controls. Insolation has positive, statistically significant effects on fertility for both non-Hispanic blacks and whites, but the effects are stronger and the pattern of effect different for black mothers than white mothers. Poisson estimates from the main model suggest that a 1kWh increase in average daily insolation in the conception month - approximately the difference in sunshine experienced in the typical September vs. October - increases non-Hispanic black conceptions by 1% and non-Hispanic white conceptions by 0.6%. Allowing insolation's effect to differ by maternal characteristic suggests that the racial differences are not being driven by differences in socioeconomic status (SES). Models that allow for more complicated timing of insolation's effect further suggest that insolation pushes black (white) conceptions into the unfavorable (favorable) season of birth. These estimated effects and our decomposition analyses suggest that insolation - and the implied Vitamin D deficiency underlying its effect-helps explain why black conceptions are more likely to display a seasonal pattern that is disadvantageous to birth outcomes.

Cigarette Taxes, Smoking-and Exercise?

This research provides the first in-depth analysis of the effect that increased cigarette taxes have on exercise behavior. Smoking may diminish the ability to exercise; individuals may also use exercise to compensate for the harmful health effects of smoking or to avoid gaining weight if they cut back. Our conceptual model highlights these and several other avenues for effect and reveals that the predicted effect of cigarette costs on exercise behavior is theoretically ambiguous. To investigate the relationship empirically, 1994-2012 data from the behavioral risk factor surveillance system are combined with state level cigarette tax rates and other state level variables. Several measures of both smoking and exercise behavior are created and estimated in reduced form models. Our results suggest that both smoking and exercise are reduced by cigarette taxes. However, the effects on exercise may be more complicated as we find that certain groups, such as young adults or those who have recently quit smoking, are affected differently. Our analyses also show that the responsiveness of both smoking and exercise behavior to cigarette costs is much smaller in the 2000s, an era of high-tax increases. Copyright © 2016 John Wiley & Sons, Ltd.

Advancing medical device innovation through collaboration and coordination of structured data capture pilots: Report from the Medical Device Epidemiology Network (MDEpiNet) Specific, Measurable, Achievable, Results-Oriented, Time Bound (SMART) Think Tank.

The Medical Device Epidemiology Network (MDEpiNet) is a public private partnership (PPP) that provides a platform for collaboration on medical device evaluation and depth of expertise for supporting pilots to capture, exchange and use device information for improving device safety and protecting public health. The MDEpiNet SMART Think Tank, held in February, 2013, sought to engage expert stakeholders who were committed to improving the capture of device data, including Unique Device Identification (UDI), in key electronic health information. Prior to the Think Tank there was limited collaboration among stakeholders beyond a few single health care organizations engaged in electronic capture and exchange of device data. The Think Tank resulted in what has become two sustainable multi-stakeholder device data capture initiatives, BUILD and VANGUARD. These initiatives continue to mature within the MDEpiNet PPP structure and are well aligned with the goals outlined in recent FDA-initiated National Medical Device Planning Board and Medical Device Registry Task Force white papers as well as the vision for the National Evaluation System for health Technology.%.

How Has Elderly Migration Changed in the Twenty-First Century? What the Data Can-and Cannot-Tell Us.

Interstate elderly migration has strong implications for state tax policies and health care systems, yet little is known about how it has changed in the twenty-first century. Its relative rarity requires a large data set with which to construct reliable measures, and the replacement of the U.S. Census long form (CLF) with the American Community Survey (ACS) has made such updates difficult. Two commonly used alternative migration data sources-the Current Population Survey (CPS) and the Statistics of Income (SOI) program of the Internal Revenue Service (IRS)-suffer serious limitations in studying the migration of any subpopulation, including the elderly. Our study informs migration research in the post-2000 era by identifying methodological differences between data sources and devising strategies for reconciling the CLF and ACS. Our investigation focusing on the elderly suggests that the ACS can generate comparable migration data that reveal a continuation of previously identified geographic patterns as well as changes unique to the 2000s. However, its changed definition of residence and survey timing leaves us unable to construct a comparable national migration rate, suggesting that one must use national trends in the smaller CPS to investigate whether elderly migration has increased or decreased in the twenty-first century.

"Going with the flow"--a comparison of interstate elderly migration during 1970-2000 using the (I)PUMS versus full census data.

OBJECTIVES: We investigate how much state-to-state elderly migration patterns have changed during 1970-2000 and compare the findings from 2 commonly used sources of data, the census flow tabulations and the integrated public use microdata series (IPUMS). METHODS: We calculate descriptive statistics such as migration rates, the distribution of top destination and origin states, and a new migration Herfindahl-Hirschman Index that measures geographic concentration. Comparisons over time and between data sources are formalized using correlations and regression analyses that permit persistent flow patterns. RESULTS: After an increase between 1970 and 1980, elderly migration rates have been stable, with a slight decline. Elderly migration has become less geographically concentrated; the decline of California and Florida and ascension of Nevada and the Carolinas as top destinations are evident. Correlation and regression analyses reveal that migration patterns are overall very persistent over time, especially using census tabulations based on a larger sample. DISCUSSION: Elderly migration patterns have been quite stable since 1970. Using the IPUMS, as most migration studies do, exaggerates the changes in elderly migration over time in both descriptive and statistical analyses, a result that is likely due to its smaller sample size and the relative rarity of an interstate move.

Maternal health: does prenatal care make a difference?

This research attempts to close an important gap in health economics regarding the efficacy of prenatal care and policies designed to improve access to that care, such as Medicaid. We argue that a key beneficiary-- the mother-- has been left completely out of the analysis. If prenatal care significantly improves the health of the mother, then concluding that prenatal care is 'ineffective' or that the Medicaid expansions are a 'failure' is premature. This paper seeks to rectify the oversight by estimating the impact of prenatal care on maternal health and the associated cost savings. We first set up a joint maternal-infant health production framework that informs our empirical analysis. Using data from the National Maternal and Infant Health Survey, we estimate the effects of prenatal care on several different measures of maternal health such as body weight status and excessive hospitalizations. Our results suggest that receiving timely and adequate prenatal care may increase the probability of maintaining a healthy weight after the birth and, perhaps for blacks, of avoiding a lengthy hospitalization after the delivery. Given the costs to society of obesity and hospitalization, these are benefits worth exploring before making conclusions about the effectiveness of prenatal care-- and Medicaid.

Is prenatal care really ineffective? Or, is the 'devil' in the distribution?

Prenatal care should improve infant health, yet research frequently finds only weak effects. If there are two kinds of pregnancies, 'complicated' and 'normal' ones, then combining these pregnancies may lead prenatal care to appear ineffective. Data from the National Maternal and Infant Health Survey (NMIHS) offers compelling evidence. The standard 2SLS approach yields obviously bimodal residuals and frequently insignificant prenatal care coefficients. In contrast, estimating birth weights with a finite mixture model yields estimates revealing that prenatal care has a substantial effect on 'normal' pregnancies. Our Monte Carlo experiment confirms that ignoring even a small proportion of 'complicated' pregnancies can lead prenatal care to appear unimportant.

Pulmonary agenesis: expansion of the VCFS phenotype.

In this report, we describe a child with the typical craniofacial manifestations of velocardiofacial syndrome (VCFS), a 22q11.2 deletion, and unilateral pulmonary agenesis. The 22q11.2 deletion syndromes are associated with malformations presumed to be caused by a disruption of cephalic neural crest cell migration during the fourth week of embryonic development. We suggest that the pulmonary agenesis seen in this case is related to a disruption of the dorsal aortic arch development that selectively interfered with lung bud growth. We suggest that pulmonary agenesis should be considered part of the spectrum of malformations seen in 22q11.2 deletion.