[Show abstract][Hide abstract] ABSTRACT: Over the past ten years, unconventional gas and oil drilling (UGOD) has markedly expanded in the United States. Despite substantial increases in well drilling, the health consequences of UGOD toxicant exposure remain unclear. This study examines an association between wells and healthcare use by zip code from 2007 to 2011 in Pennsylvania. Inpatient discharge databases from the Pennsylvania Healthcare Cost Containment Council were correlated with active wells by zip code in three counties in Pennsylvania. For overall inpatient prevalence rates and 25 specific medical categories, the association of inpatient prevalence rates with number of wells per zip code and, separately, with wells per km<sup>2</sup> (separated into quantiles and defined as well density) were estimated using fixed-effects Poisson models. To account for multiple comparisons, a Bonferroni correction with associations of p<0.00096 was considered statistically significant. Cardiology inpatient prevalence rates were significantly associated with number of wells per zip code (p<0.00096) and wells per km<sup>2</sup> (p<0.00096) while neurology inpatient prevalence rates were significantly associated with wells per km<sup>2</sup> (p<0.00096). Furthermore, evidence also supported an association between well density and inpatient prevalence rates for the medical categories of dermatology, neurology, oncology, and urology. These data suggest that UGOD wells, which dramatically increased in the past decade, were associated with increased inpatient prevalence rates within specific medical categories in Pennsylvania. Further studies are necessary to address healthcare costs of UGOD and determine whether specific toxicants or combinations are associated with organ-specific responses.
[Show abstract][Hide abstract] ABSTRACT: Hypoplastic left heart syndrome is the most expensive birth defect managed in the United States, with a 5-year survival rate below 70%. Increasing evidence suggests that hospital volumes are inversely associated with mortality for infants with single ventricles undergoing stage 1 surgical palliation. Our aim was to examine the relative effects of surgeon and institutional volumes on outcomes and resource utilisation for these children.
A retrospective study was conducted using the Pediatric Health Information System database to examine the effects of the number of procedures performed per surgeon and per centre on mortality, costs, and post-operative length of stay for infants undergoing Risk Adjustment for Congenital Heart Surgery risk category six operations at tertiary-care paediatric hospitals, from 1 January, 2004 to 31 December, 2013. Multivariable modelling was used, adjusting for patient and institutional characteristics. Gaussian kernel densities were constructed to show the relative distributions of the effects of individual institutions and surgeons, before and after adjusting for the number of cases performed.
A total of 2880 infants from 35 institutions met the inclusion criteria. Mortality was 15.0%. Median post-operative length of stay was 24 days (IQR 14-41). Median standardized inpatient hospital costs were $156,000 (IQR $108,000-$248,000) in 2013 dollars. In the multivariable analyses, higher institutional volume was inversely associated with mortality (p=0.001), post-operative length of stay (p=0.004), and costs (p=0.001). Surgeon volume was associated with none of the measured outcomes. Neither institutional nor surgeon volumes explained much of the wide variation in outcomes and resource utilization observed between institutions and between surgeons.
Increased institutional - but not surgeon - volumes are associated with reduced mortality, post-operative length of stay, and costs for infants undergoing stage 1 palliation.
Full-text · Article · Jul 2015 · Cardiology in the Young
[Show abstract][Hide abstract] ABSTRACT: Evidence shows that pollution exposure early in life is detrimental to near-term health, and an increasing body of evidence suggests that early-childhood health influences health and human capital outcomes later in life. This article reviews the economic research that brings these two literatures together. We begin with a conceptual model that highlights the core relationships across the life cycle. We then review the literature concerned with such estimates, focusing particularly on identification strategies to mitigate concerns regarding endogenous exposure. The nascent empirical literature provides both direct and indirect evidence that early-childhood exposure to pollution significantly impacts later-life outcomes. We discuss the potential policy implications of these long-lasting effects and conclude with a number of promising avenues for future research.
No preview · Article · Nov 2014 · Annual Review of Resource Economics
[Show abstract][Hide abstract] ABSTRACT: Outdoor air pollution, largely from fossil fuel burning, is a major cause of morbidity and mortality in the United States, costing billions of dollars every year in health care and loss of productivity. The developing fetus and young child are especially vulnerable to neurotoxicants, such as polycyclic aromatic hydrocarbons (PAH) released to ambient air by combustion of fossil fuel and other organic material. Low-income populations are disproportionately exposed to air pollution. On the basis of the results of a prospective cohort study in a low-income population in New York City (NYC) that found a significant inverse association between child IQ and prenatal exposure to airborne PAH, we estimated the increase in IQ and related lifetime earnings in a low-income urban population as a result of a hypothesized modest reduction of ambient PAH concentrations in NYC of 0.25 ng/m(3). For reference, the current estimated annual mean PAH concentration is ~1 ng/m(3). Restricting to NYC Medicaid births and using a 5 per cent discount rate, we estimated the gain in lifetime earnings due to IQ increase for a single year cohort to be US$215 million (best estimate). Using much more conservative assumptions, the estimate was $43 million. This analysis suggests that a modest reduction in ambient concentrations of PAH is associated with substantial economic benefits to children.Journal of Public Health Policy advance online publication, 8 May 2014; doi:10.1057/jphp.2014.14.
No preview · Article · May 2014 · Journal of Public Health Policy
[Show abstract][Hide abstract] ABSTRACT: Bisphenol A (BPA), a high production chemical commonly found in plastics, has drawn great attention from researchers due to the substance's potential toxicity. Using data from three National Health and Nutrition Examination Survey (NHANES) cycles, we explored the consistency and robustness of BPA's reported effects on coronary heart disease and diabetes.
WE REPORT THE USE OF THREE DIFFERENT STATISTICAL MODELS IN THE ANALYSIS OF BPA: (1) logistic regression, (2) log-linear regression, and (3) dose-response logistic regression. In each variation, confounders were added in six blocks to account for demographics, urinary creatinine, source of BPA exposure, healthy behaviours, and phthalate exposure. Results were sensitive to the variations in functional form of our statistical models, but no single model yielded consistent results across NHANES cycles. Reported ORs were also found to be sensitive to inclusion/exclusion criteria. Further, observed effects, which were most pronounced in NHANES 2003-04, could not be explained away by confounding.
Limitations in the NHANES data and a poor understanding of the mode of action of BPA have made it difficult to develop informative statistical models. Given the sensitivity of effect estimates to functional form, researchers should report results using multiple specifications with different assumptions about BPA measurement, thus allowing for the identification of potential discrepancies in the data.
[Show abstract][Hide abstract] ABSTRACT: BACKGROUND: Identifying patients most at risk for hospital- and community-associated infections is one essential strategy for preventing infections. OBJECTIVE: To investigate whether rates of community- and healthcare-associated bloodstream and surgical site infections varied by patient gender in a large cohort after controlling for a wide variety of possible confounders. DESIGN: Retrospective cohort study. PARTICIPANTS: All patients discharged from January 1, 2006 through December 31, 2008 (133,756 adult discharges and 66,592 pediatric discharges) from a 650-bed tertiary care hospital, a 220-bed community hospital, and a 280-bed pediatric acute care hospital within a large, academic medical center in New York, NY. MAIN MEASURES: Data were collected retrospectively from various electronic sources shared by the hospitals and linked using patients' unique medical record numbers. Infections were identified using previously validated computerized algorithms. KEY RESULTS: Odds of community-associated bloodstream infections, healthcare-associated bloodstream infections, and surgical site infections were significantly lower for women than for men after controlling for present-on-admission patient characteristics and events during the hospital stay [odds ratios (95 % confidence intervals) were 0.85 (0.77-0.93), 0.82 (0.74-0.91), and 0.78 (0.68-0.91), respectively]. Gender differences were greatest for older adolescents (12-17 years) and adults 18-49 years and least for young children (<12 years) and older adults (≥70 years). CONCLUSIONS: In this cohort, men were at higher risk for bloodstream and surgical site infections, possibly due to differences in propensity for skin colonization or other anatomical differences.
No preview · Article · Apr 2013 · Journal of General Internal Medicine
[Show abstract][Hide abstract] ABSTRACT: In this review, we discuss three major contributions economists have made to our understanding of the relationship between the environment and individual well-being. First, in explicitly recognizing how optimizing behavior, particularly in the form of residential sorting, can lead to non-random assignment of pollution, economists have employed a wide range of quasi-experimental techniques to develop causal estimates of the effect of pollution. Second, economic research has placed a considerable focus on the role of avoidance behavior, which is an important component for understanding the difference between biological and behavioral effects of pollution and for proper welfare calculations. Lastly, economic research has expanded the focus of analysis beyond traditional health outcomes to include measures of human capital, including labor supply, productivity, and cognition. Our review of the quasi-experimental evidence on this topic suggests that pollution does indeed have a wide range of effects on individual well-being, even at levels well below current regulatory standards. Given the importance of health and human capital as an engine for economic growth, these findings underscore the role of environmental conditions as an important factor of production.
No preview · Article · Apr 2013 · Journal of Economic Literature
[Show abstract][Hide abstract] ABSTRACT: This paper examines the effect of energy production on newborn health using a recent strike that affected oil refineries in France as a natural experiment. First, we show that the temporary reduction in refining lead to a significant reduction in sulfur dioxide (SO2) concentrations. Second, this shock significantly increased birth weight and gestational age of newborns, particularly for those exposed to the strike during the third trimester of pregnancy. Back-of-the-envelope calculations suggest that a 1 unit decline in SO2 leads to a 196 million euro increase in lifetime earnings per birth cohort. This externality from oil refineries should be an important part of policy discussions surrounding the production of energy.Institutional subscribers to the NBER working paper series, and residents of developing countries may download this paper without additional charge at www.nber.org.
[Show abstract][Hide abstract] ABSTRACT: This paper provides estimates of the effects of in utero exposure to contaminated drinking water on fetal health. To do this, we examine the universe of birth records and drinking water testing results for the state of New Jersey from 1997 to 2007. Our data enable us to compare outcomes across siblings who were potentially exposed to differing levels of harmful contaminants from drinking water while in utero. We find small effects of drinking water contamination on all children, but large and statistically significant effects on birth weight and gestation of infants born to less educated mothers. We also show that those mothers who were most affected by contamination were the least likely to move between births in response to contamination.
Quelque chose dans l'eau: eau potable contaminée et santé du nourrisson. Ce mémoire développe des estimations des effets d'une exposition in utero à de l'eau potable contaminée sur la santé du fœtus. Pour ce faire, on examine l'ensemble des registres de naissance et des résultats de tests de l'eau potable dans l'état du New Jersey entre 1997 et 2007. Ces données permettent de comparer les résultats entre frères et soeurs qui ont potentiellement été exposés à des niveaux différents de contamination de l'eau potable quand ils étaient in utero. On détecte de petits effets de la contamination de l'eau sur tous les enfants, mais des effets importants et statistiquement significatifs sur le poids à la naissance et sur la gestation des nourrissons portés par des mères moins instruites. On montre aussi que ces mères qui sont les plus affectées par la contamination de l'eau sont celles qui sont le moins susceptibles de déménager entre les naissances en raison de la contamination.
No preview · Article · Mar 2013 · Canadian Journal of Economics/Revue Canadienne d`Economique
[Show abstract][Hide abstract] ABSTRACT: Design. We conducted a retrospective cohort study to examine the role played by length of hospital stay in the risk of healthcare-associated bloodstream infection (BSI), independent of demographic and clinical risk factors for BSI. Patients. We employed data from 113,893 admissions from inpatients discharged between 2006 and 2008. Setting. Large tertiary healthcare center in New York City. Methods. We estimated the crude and adjusted hazard of BSI by conducting logistic regression using a person-day data structure. The covariates included in the fully adjusted model included age, sex, Charlson score of comorbidity, renal failure, and malignancy as static variables and central venous catheterization, mechanical ventilation, and intensive care unit stay as time-varying variables. Results. In the crude model, we observed a nonlinear increasing hazard of BSI with increasing hospital stay. This trend was reduced to a constant hazard when fully adjusted for demographic and clinical risk factors for BSI. Conclusion. The association between longer length of hospital stay and increased risk of infection can largely be explained by the increased duration of stay among those who have underlying morbidity and require invasive procedures. We should take caution in attributing the association between length of stay and BSI to a direct negative impact of the healthcare environment.
Full-text · Article · Dec 2012 · Infection Control and Hospital Epidemiology
[Show abstract][Hide abstract] ABSTRACT: We compared differences in the hospital charges, length of hospital stay, and mortality between patients with healthcare- and community-associated bloodstream infections, urinary tract infections, and pneumonia due to antimicrobial-resistant versus -susceptible bacterial strains.
A retrospective analysis of an electronic database compiled from laboratory, pharmacy, surgery, financial, and patient location and device utilization sources was undertaken on 5699 inpatients who developed healthcare- or community-associated infections between 2006 and 2008 from 4 hospitals (1 community, 1 pediatric, 2 tertiary/quaternary care) in Manhattan. The main outcome measures were hospital charges, length of stay, and mortality among patients with antimicrobial-resistant and -susceptible infections caused by Staphylococcus aureus, Enterococcus faecium, Enterococcus faecalis, Klebsiella pneumoniae, Pseudomonas aeruginosa, and Acinetobacter baumannii.
Controlling for multiple confounders using linear regression and nearest neighbor matching based on propensity score estimates, resistant healthcare- and community-associated infections, when compared with susceptible strains of the same organism, were associated with significantly higher charges ($15,626; confidence interval [CI], $4339-$26,913 and $25,573; CI, $9331-$41,816, respectively) and longer hospital stays for community-associated infections (3.3; CI, 1.5-5.4). Patients with resistant healthcare-associated infections also had a significantly higher death rate (0.04; CI, 0.01-0.08).
With careful matching of patients infected with the same organism, antimicrobial resistance was associated with higher charges, length of stay, and death rates. The difference in estimates after accounting for censoring for death highlight divergent social and hospital incentives in reducing patient risk for antimicrobial resistant infections.
Full-text · Article · Jun 2012 · Clinical Infectious Diseases
[Show abstract][Hide abstract] ABSTRACT: Many human studies have shown a correlation between air pollution and poor health in children. This paper focuses on studies that employ quasi-experimental designs to study the effects of air pollution on specific populations in an effort to isolate the causes and minimize the effect of confounding factors. Human studies of many and varied designs have found that exposure to some pollutants, even at levels below regulatory thresholds, adversely affects health. Our review of quasi-experimental studies adds additional support to these findings. Together, the research suggests that lowering the thresholds for acceptable air pollution levels may be a prudent and necessary step toward improving population health, especially among the most vulnerable members of society: infants and children. Policy makers should also consider providing specific information to families and pregnant women about when and where the risk of pollution exposure is highest, so that they can minimize their exposure or avoid it altogether.
[Show abstract][Hide abstract] ABSTRACT: Despite a push to create electronic health records and a plethora of healthcare data from disparate sources, there are no data from a single electronic source that provide a full picture of a patient's hospital course. This paper describes a process to utilize electronically available inpatient hospital data for research. We linked several different sources of extracted data, including clinical, procedural, administrative, and accounting data, using patients' medical record numbers to compile a cohesive, comprehensive account of patient encounters. Challenges encountered included (1) interacting with distinct administrative units to locate data elements; (2) finding a secure, central location to house the data; (3) appropriately defining health measures of interest; (4) obtaining and linking these data to create a usable format for conducting research; and (5) dealing with missing data. Although the resulting data set is incredibly rich and likely to prove useful for a wide range of clinical and comparative effectiveness research questions, there are multiple challenges associated with linking hospital data to improve the quality of patient care.
Preview · Article · Oct 2011 · Clinical and Translational Science
[Show abstract][Hide abstract] ABSTRACT: We examine the impact of poor water quality on avoidance behavior by estimating the change in bottled water purchases in response to drinking water violations. Using data from a national grocery chain matched with water quality violations, we find an increase in bottled water sales of 22 percent from violations due to microorganisms and 17 percent from violations due to elements and chemicals. Back-of-the envelope calculations yield costs of avoidance behavior at roughly $60 million for all nationwide violations in 2005, which likely reflects a significant understatement of the total willingness to pay to eliminate violations.
Preview · Article · May 2011 · American Economic Review
[Show abstract][Hide abstract] ABSTRACT: Environmental protection is typically cast as a tax on the labor market and the economy in general. Since a large body of evidence links pollution with poor health, and health is an important part of human capital, efforts to reduce pollution could plausibly be viewed as an investment in human capital and thus a tool for promoting economic growth. While a handful of studies have documented the impacts of pollution on labor supply, this paper is the first to rigorously assess the less visible but likely more pervasive impacts on worker productivity. In particular, we exploit a novel panel dataset of daily farm worker output as recorded under piece rate contracts merged with data on environmental conditions to relate the plausibly exogenous daily variations in ozone with worker productivity. We find robust evidence that ozone levels well below federal air quality standards have a significant impact on productivity: a 10 ppb decrease in ozone concentrations increases worker productivity by 4.2 percent.
Preview · Article · Apr 2011 · American Economic Review
[Show abstract][Hide abstract] ABSTRACT: We explored whether a successful randomized controlled trial of early education, the Carolina Abecedarian Project (ABC), which enrolled infants from 1972 to 1977 at the Frank Porter Graham Child Development Institute in Chapel Hill, North Carolina, improved health outcomes and behaviors by 21 years of age.
ABC randomized 111 infants to receive an intensive early education program or nutritional supplements and parental counseling alone; participants have been followed to the present day. We examined the effect of ABC on health outcomes and behavioral risk factors when participants were aged 21 years, and then explored the mediators of this relationship.
Relative to the control group, the ABC treatment group was previously found to have improved cognition and educational attainment. We found that the intervention also improved heath (P = .05) and health behaviors (P = .03) when participants were aged 21 years. These improvements in behaviors were not mediated by IQ, math and reading scores at 15 years of age, educational attainment, or health insurance.
Effective early education programs may improve health and reduce risky health behaviors in adulthood.
Full-text · Article · Mar 2011 · American Journal of Public Health
[Show abstract][Hide abstract] ABSTRACT: Early life exposure to ambient polycyclic aromatic hydrocarbons (PAHs) can result in developmental delay. The negative health effects of PAHs have been well-documented but the cost of developmental delay due to PAH exposure has not been studied. The Columbia Center for Children's Environmental Health previously has reported the significant effect of prenatal exposure to ambient PAHs on delayed mental development at three years, using the Bayley Scales in a cohort of low-income women and children in New York City (NYC). Here we have used the cohort results to estimate the annual costs of preschool special education services for low-income NYC children with developmental delay due to PAH exposure using the Environmentally Attributable Fraction method. The estimated cost of PAH-exposure-related services is over $13.7 million per year for Medicaid births in NYC. This high cost supports policies to reduce level of PAHs in NYC air.
Full-text · Article · Feb 2011 · Journal of Health Care for the Poor and Underserved