Statistical Challenges in the Analysis of Biomarkers of Environmental Chemical Exposures for Perinatal Epidemiology
AbstractPurpose of ReviewBiomarkers are widely used in perinatal epidemiology to examine the health effects of environmental chemical exposures during pregnancy. These measurements take the form of chemical concentrations measured in blood, urine, or other biospecimens. Biomarkers have the advantage of providing objective estimates of chemical exposures from multiple sources. However, they are difficult to handle at the data analysis stage. We review recent trends and developments in the statistical analysis of biomarkers with particular emphasis on exposure assessment and multivariable modeling.Recent FindingsSix statisti...
Source: Current Epidemiology Reports - July 4, 2018 Category: Epidemiology Source Type: research
Understanding the Assumptions Underlying Instrumental Variable Analyses: a Brief Review of Falsification Strategies and Related Tools
AbstractPurpose of ReviewInstrumental variable (IV) methods continue to be applied to questions ranging from genetic to social epidemiology. In the epidemiologic literature, discussion of whether the assumptions underlying IV analyses hold is often limited to only certain assumptions and even then, arguments are mostly made using subject matter knowledge. To complement subject matter knowledge, there exist a variety of falsification strategies and other tools for weighing the plausibility of the assumptions underlying IV analyses.Recent FindingsThere are many tools that can refute the IV assumptions or help estimate the ma...
Source: Current Epidemiology Reports - June 22, 2018 Category: Epidemiology Source Type: research
Achieving Optimal Cardiovascular Health: a Social Epidemiological Approach
AbstractPurpose of ReviewThe American Heart Association (AHA) created the cardiovascular health (CVH) index to measure and monitor population-level reduction of cardiovascular disease (CVD) risk, with a goal of 20% reduction in CVD morbidity and mortality by 2020. Few U.S. adults meet all seven ideal CVH metrics (non-smoking behavior, healthy diet and body weight, active lifestyle, good cholesterol, glucose, and blood pressure scores), with 17% of men and women only achieving five or more ideal CVH metrics. This review describes the importance of considering sociodemographic, psychosocial, and behavioral factors as key str...
Source: Current Epidemiology Reports - June 21, 2018 Category: Epidemiology Source Type: research
A Review of Time Scale Fundamentals in the g-Formula and Insidious Selection Bias
AbstractPurpose of ReviewWe review recent examples of data analysis with the g-formula, a powerful tool for analyzing longitudinal data and survival analysis. Specifically, we focus on the common choices of time scale and review inferential issues that may arise.Recent FindingsResearchers are increasingly engaged with questions that require time scales subject to left truncation and right censoring. The assumptions necessary for allowing right censoring are well defined in the literature, whereas similar assumptions for left truncation are not well defined. Policy and biologic considerations sometimes dictate that observat...
Source: Current Epidemiology Reports - June 15, 2018 Category: Epidemiology Source Type: research
Established and Emerging Environmental Contributors to Disparities in Asthma and Chronic Obstructive Pulmonary Disease
The objective of this review is to evaluate the evidence supporting a link between disproportionate environmental exposures and these health disparities.Recent FindingsStudies suggest that various co-occurring factors related to the home environment, neighborhood environment, non-modifiable individual factors, and individual behaviors and attributes can increase or modify the risk of adverse respiratory outcomes among socioeconomically disadvantaged and racially/ethnically diverse populations. Pollutants in the home environment, including particulate matter, nitrogen dioxide, and pesticides, are elevated among lower socioe...
Source: Current Epidemiology Reports - May 25, 2018 Category: Epidemiology Source Type: research
Mendelian Randomization Studies of Cancer Risk: a Literature Review
AbstractPurpose of ReviewIn this paper, we summarize prior studies that have used Mendelian randomization (MR) methods to study the effects of exposures, lifestyle factors, physical traits, and/or biomarkers on cancer risk in humans. Many such risk factors have been associated with cancer risk in observational studies, and the MR approach can be used to provide evidence as to whether these associations represent causal relationships. MR methods require a risk factor of interest to have known genetic determinants that can be used as proxies for the risk factor (i.e., “instrumental variables” or IVs), and these can be us...
Source: Current Epidemiology Reports - May 18, 2018 Category: Epidemiology Source Type: research
Environmental Determinants of Insufficient Sleep and Sleep Disorders: Implications for Population Health
AbstractPurpose of ReviewSleep is important for overall health and well-being. Insufficient sleep and sleep disorders are highly prevalent among adults and children and therefore a public health burden, particularly because poor sleep is associated with adverse health outcomes. Emerging evidence has demonstrated that environmental factors at the household- and neighborhood-level can alter healthy sleep. This paper will [1] review recent literature on the environmental determinants of sleep among adults as well as children and adolescents and [2] discuss the opportunities and challenges for advancing research on the environ...
Source: Current Epidemiology Reports - May 5, 2018 Category: Epidemiology Source Type: research
Aviation Noise and Cardiovascular Health in the United States: a Review of the Evidence and Recommendations for Research Direction
AbstractPurpose of the ReviewIn the USA, there is mounting pressure on aviation operators and regulators to address concerns about community impacts of aircraft noise given increasing evidence of adverse health impacts, continuing community complaints, availability of cost-effective programs to reduce exposures to aircraft noise, and more stringent international policies. In the USA, regulation of civil aviation noise is the responsibility of the Federal Aviation Administration (FAA), which requires a “significant body of scientific support,” particularly applicable to the USA, to inform health-based policy and regulat...
Source: Current Epidemiology Reports - April 26, 2018 Category: Epidemiology Source Type: research
A Review of Environmental Epidemiology Studies in Southwestern and Mountain West Rural Minority Populations
AbstractPurpose of ReviewThis review summarizes the recent epidemiologic literature examining environmental exposures and health outcomes in rural, minority populations in the southwestern and mountain west region of the USA identifying areas requiring further data and research.Recent FindingsRecent studies (2012 –2017) in this region have primarily focused on arsenic exposure (n = 10 studies) with similar results reported across populations in this region. Associations between arsenic and cadmium were reported for cardiovascular and kidney disease, type II diabetes, cognitive function, hypothyroidism, and increased p...
Source: Current Epidemiology Reports - April 21, 2018 Category: Epidemiology Source Type: research
The Impact of Joint Misclassification of Exposures and Outcomes on the Results of Epidemiologic Research
AbstractPurpose of ReviewWe discuss the causes and impacts of dependent nondifferential misclassification with particular attention to the mechanisms by which dependent misclassification occurs. We also present suggestions for how to reduce the potential for dependent misclassification.Recent FindingsMisclassification is ubiquitous in associations between exposures and outcomes in epidemiology. While most epidemiologic textbooks cover independent nondifferential misclassification of both exposures and outcomes, the impact of joint misclassification of exposure and outcome is a poorly understood problem.SummaryUnder common ...
Source: Current Epidemiology Reports - April 20, 2018 Category: Epidemiology Source Type: research
Longer-Term Outdoor Temperatures and Health Effects: a Review
AbstractPurpose of ReviewOur goal was to assess current literature and knowledge on associations between characteristics (mean, variability, extremes) of ambient temperatures and human health. We were motivated by concerns that climate change, which operates on a time frame of decades or longer, may influence not only shorter-term associations between weather and health (daily/weekly) but also have enduring implications for population health. We reviewed papers published between 2010 and 2017 on the health effects of longer-term (3 weeks to years) exposures to ambient temperature. We sought to answer: “What health outc...
Source: Current Epidemiology Reports - April 17, 2018 Category: Epidemiology Source Type: research
The Replication Crisis in Epidemiology: Snowball, Snow Job, or Winter Solstice?
AbstractPurpose of ReviewLike a snowball rolling down a steep hill, the most recent crisis over the perceived lack of reproducibility of scientific results has outpaced the evidence of crisis. It has led to new actions and new guidelines that have been rushed to market without plans for evaluation, metrics for success, or due consideration of the potential for unintended consequences.Recent FindingsThe perception of the crisis is at least partly a snow job, heavily influenced by a small number of centers lavishly funded by a single foundation, with undue and unsupported attention to preregistration as a solution to the per...
Source: Current Epidemiology Reports - April 12, 2018 Category: Epidemiology Source Type: research
Ambient and Traffic-Related Air Pollution Exposures as Novel Risk Factors for Metabolic Dysfunction and Type 2 Diabetes
AbstractPurpose of ReviewDiabetes mellitus is a top contributor to the global burden of mortality and disability in adults. There has also been a slow but steady rise in prediabetes and type 2 diabetes in youth. The current review summarizes recent findings regarding the impact of increased exposure to air pollutants on the type 2 diabetes epidemic.Recent FindingsHuman and animal studies provide strong evidence that exposures to ambient and traffic-related air pollutants such as particulate matter (PM), nitrogen dioxide (NO2), and nitrogen oxides (NOx) play an important role in metabolic dysfunction and type 2 diabetes eti...
Source: Current Epidemiology Reports - April 10, 2018 Category: Epidemiology Source Type: research
Environmental Exposure Mixtures: Questions and Methods to Address Them
AbstractPurpose of This ReviewThis review provides a summary of statistical approaches that researchers can use to study environmental exposure mixtures. Two primary considerations are the form of the research question and the statistical tools best suited to address that question. Because the choice of statistical tools is not rigid, we make recommendations about when each tool may be most useful.Recent FindingsWhen dimensionality is relatively low, some statistical tools yield easily interpretable estimates of effect (e.g., risk ratio, odds ratio) or intervention impacts. When dimensionality increases, it is often necess...
Source: Current Epidemiology Reports - April 5, 2018 Category: Epidemiology Source Type: research
Air Pollution and Breast Cancer: a Review
AbstractPurpose of ReviewBreast cancer is the most common cancer diagnosed among US women. Air pollution is a pervasive mixture of chemicals containing carcinogenic compounds and chemicals with endocrine-disrupting properties. In the present review, we examine the epidemiologic evidence regarding the association between air pollution measures and breast cancer risk.Recent FindingsWe identified 17 studies evaluating the risk of breast cancer associated with air pollution. A higher risk of breast cancer has been associated with nitrogen dioxide (NO2) and nitrogen oxide (NOx) levels, both of which are proxies for traffic expo...
Source: Current Epidemiology Reports - March 27, 2018 Category: Epidemiology Source Type: research
