ASSESSING WATERBORNE RISKS: AN INTRODUCTION

EPA Science Inventory

Information in this article can help readers evaluate the results of epidemiologic studies of

waterborne disease risks. It is important that readers understand the various epidemiologic study

designs, their strengths and limitations, and potential biases. Terminolog...

Evaluation of a rule-based method for epidemiological document classification towards the automation of systematic reviews.

PubMed

Karystianis, George; Thayer, Kristina; Wolfe, Mary; Tsafnat, Guy

2017-06-01

Most data extraction efforts in epidemiology are focused on obtaining targeted information from clinical trials. In contrast, limited research has been conducted on the identification of information from observational studies, a major source for human evidence in many fields, including environmental health. The recognition of key epidemiological information (e.g., exposures) through text mining techniques can assist in the automation of systematic reviews and other evidence summaries. We designed and applied a knowledge-driven, rule-based approach to identify targeted information (study design, participant population, exposure, outcome, confounding factors, and the country where the study was conducted) from abstracts of epidemiological studies included in several systematic reviews of environmental health exposures. The rules were based on common syntactical patterns observed in text and are thus not specific to any systematic review. To validate the general applicability of our approach, we compared the data extracted using our approach versus hand curation for 35 epidemiological study abstracts manually selected for inclusion in two systematic reviews. The returned F-score, precision, and recall ranged from 70% to 98%, 81% to 100%, and 54% to 97%, respectively. The highest precision was observed for exposure, outcome and population (100%) while recall was best for exposure and study design with 97% and 89%, respectively. The lowest recall was observed for the population (54%), which also had the lowest F-score (70%). The generated performance of our text-mining approach demonstrated encouraging results for the identification of targeted information from observational epidemiological study abstracts related to environmental exposures. We have demonstrated that rules based on generic syntactic patterns in one corpus can be applied to other observational study design by simple interchanging the dictionaries aiming to identify certain characteristics (i.e., outcomes, exposures). At the document level, the recognised information can assist in the selection and categorization of studies included in a systematic review. Copyright © 2017 Elsevier Inc. All rights reserved.

Research Methods in Healthcare Epidemiology and Antimicrobial Stewardship-Observational Studies.

PubMed

Snyder, Graham M; Young, Heather; Varman, Meera; Milstone, Aaron M; Harris, Anthony D; Munoz-Price, Silvia

2016-10-01

Observational studies compare outcomes among subjects with and without an exposure of interest, without intervention from study investigators. Observational studies can be designed as a prospective or retrospective cohort study or as a case-control study. In healthcare epidemiology, these observational studies often take advantage of existing healthcare databases, making them more cost-effective than clinical trials and allowing analyses of rare outcomes. This paper addresses the importance of selecting a well-defined study population, highlights key considerations for study design, and offers potential solutions including biostatistical tools that are applicable to observational study designs. Infect Control Hosp Epidemiol 2016;1-6.

A proposal for assessing study quality: Biomonitoring, Environmental Epidemiology, and Short-lived Chemicals (BEES-C) instrument.

PubMed

LaKind, Judy S; Sobus, Jon R; Goodman, Michael; Barr, Dana Boyd; Fürst, Peter; Albertini, Richard J; Arbuckle, Tye E; Schoeters, Greet; Tan, Yu-Mei; Teeguarden, Justin; Tornero-Velez, Rogelio; Weisel, Clifford P

2014-12-01

The quality of exposure assessment is a major determinant of the overall quality of any environmental epidemiology study. The use of biomonitoring as a tool for assessing exposure to ubiquitous chemicals with short physiologic half-lives began relatively recently. These chemicals present several challenges, including their presence in analytical laboratories and sampling equipment, difficulty in establishing temporal order in cross-sectional studies, short- and long-term variability in exposures and biomarker concentrations, and a paucity of information on the number of measurements required for proper exposure classification. To date, the scientific community has not developed a set of systematic guidelines for designing, implementing and interpreting studies of short-lived chemicals that use biomonitoring as the exposure metric or for evaluating the quality of this type of research for WOE assessments or for peer review of grants or publications. We describe key issues that affect epidemiology studies using biomonitoring data on short-lived chemicals and propose a systematic instrument--the Biomonitoring, Environmental Epidemiology, and Short-lived Chemicals (BEES-C) instrument--for evaluating the quality of research proposals and studies that incorporate biomonitoring data on short-lived chemicals. Quality criteria for three areas considered fundamental to the evaluation of epidemiology studies that include biological measurements of short-lived chemicals are described: 1) biomarker selection and measurement, 2) study design and execution, and 3) general epidemiological study design considerations. We recognize that the development of an evaluative tool such as BEES-C is neither simple nor non-controversial. We hope and anticipate that the instrument will initiate further discussion/debate on this topic. Copyright © 2014 The Authors. Published by Elsevier Ltd.. All rights reserved.

A proposal for assessing study quality: Biomonitoring, Environmental Epidemiology, and Short-lived Chemicals (BEES-C) instrument

PubMed Central

LaKind, Judy S.; Sobus, Jon R.; Goodman, Michael; Barr, Dana Boyd; Fürst, Peter; Albertini, Richard J.; Arbuckle, Tye E.; Schoeters, Greet; Tan, Yu-Mei; Teeguarden, Justin; Tornero-Velez, Rogelio; Weisel, Clifford P.

2015-01-01

The quality of exposure assessment is a major determinant of the overall quality of any environmental epidemiology study. The use of biomonitoring as a tool for assessing exposure to ubiquitous chemicals with short physiologic half-lives began relatively recently. These chemicals present several challenges, including their presence in analytical laboratories and sampling equipment, difficulty in establishing temporal order in cross-sectional studies, short- and long-term variability in exposures and biomarker concentrations, and a paucity of information on the number of measurements required for proper exposure classification. To date, the scientific community has not developed a set of systematic guidelines for designing, implementing and interpreting studies of short-lived chemicals that use biomonitoring as the exposure metric or for evaluating the quality of this type of research for WOE assessments or for peer review of grants or publications. We describe key issues that affect epidemiology studies using biomonitoring data on short-lived chemicals and propose a systematic instrument – the Biomonitoring, Environmental Epidemiology, and Short-lived Chemicals (BEES-C) instrument – for evaluating the quality of research proposals and studies that incorporate biomonitoring data on short-lived chemicals. Quality criteria for three areas considered fundamental to the evaluation of epidemiology studies that include biological measurements of short-lived chemicals are described: 1) biomarker selection and measurement, 2) study design and execution, and 3) general epidemiological study design considerations. We recognize that the development of an evaluative tool such as BEES-C is neither simple nor non-controversial. We hope and anticipate that the instrument will initiate further discussion/debate on this topic. PMID:25137624

Epidemiological Studies to Support the Development of Next Generation Influenza Vaccines.

PubMed

Petrie, Joshua G; Gordon, Aubree

2018-03-26

The National Institute of Allergy and Infectious Diseases recently published a strategic plan for the development of a universal influenza vaccine. This plan focuses on improving understanding of influenza infection, the development of influenza immunity, and rational design of new vaccines. Epidemiological studies such as prospective, longitudinal cohort studies are essential to the completion of these objectives. In this review, we discuss the contributions of epidemiological studies to our current knowledge of vaccines and correlates of immunity, and how they can contribute to the development and evaluation of the next generation of influenza vaccines. These studies have been critical in monitoring the effectiveness of current influenza vaccines, identifying issues such as low vaccine effectiveness, reduced effectiveness among those who receive repeated vaccination, and issues related to egg adaptation during the manufacturing process. Epidemiological studies have also identified population-level correlates of protection that can inform the design and development of next generation influenza vaccines. Going forward, there is an enduring need for epidemiological studies to continue advancing knowledge of correlates of protection and the development of immunity, to evaluate and monitor the effectiveness of next generation influenza vaccines, and to inform recommendations for their use.

Overview of risk assessment in new EPA epidemiology studies

EPA Science Inventory

Since 2003, the Office of Research and Development of the US Environmental Protection Agency has conducted a series of epidemiology studies of water quality and health effects among beach goers at beaches across the United States. These studies are designed to establish associati...

A Seven-Year Retrospective View of a Course in Epidemiology and Biostatistics.

ERIC Educational Resources Information Center

Mulvihill, Michael N.; And Others

1980-01-01

Modifications of a course in epidemiology and biostatistics, designed to facilitate the presentation of difficult material in a clinically relevant manner, are described. Key strategies include seminar sessions devoted to methods of epidemiology and the critique of pairs of published studies, and the use of a course-specific syllabus. (JMD)

History and Impact of Nutritional Epidemiology123

PubMed Central

Alpers, David H.; Bier, Dennis M.; Carpenter, Kenneth J.; McCormick, Donald B.; Miller, Anthony B.; Jacques, Paul F.

2014-01-01

The real and important role of epidemiology was discussed, noting heretofore unknown associations that led to improved understanding of the cause and prevention of individual nutritional deficiencies. However, epidemiology has been less successful in linking individual nutrients to the cause of chronic diseases, such as cancer and cardiovascular disease. Dietary changes, such as decreasing caloric intake to prevent cancer and the Mediterranean diet to prevent diabetes, were confirmed as successful approaches to modifying the incidence of chronic diseases. The role of the epidemiologist was confirmed as a collaborator, not an isolated expert of last resort. The challenge for the future is to decide which epidemiologic methods and study designs are most useful in studying chronic disease, then to determine which associations and the hypotheses derived from them are especially strong and worthy of pursuit, and finally to design randomized studies that are feasible, affordable, and likely to result in confirmation or refutation of these hypotheses. PMID:25469385

Snippets from the past: the evolution of Wade Hampton Frost's epidemiology as viewed from the American Journal of Hygiene/Epidemiology.

PubMed

Morabia, Alfredo

2013-10-01

Wade Hampton Frost, who was a Professor of Epidemiology at Johns Hopkins University from 1919 to 1938, spurred the development of epidemiologic methods. His 6 publications in the American Journal of Hygiene, which later became the American Journal of Epidemiology, comprise a 1928 Cutter lecture on a theory of epidemics, a survey-based study of tonsillectomy and immunity to Corynebacterium diphtheriae (1931), 2 papers from a longitudinal study of the incidence of minor respiratory diseases (1933 and 1935), an attack rate ratio analysis of the decline of diphtheria in Baltimore (1936), and a 1936 lecture on the age, time, and cohort analysis of tuberculosis mortality. These 6 American Journal of Hygiene /American Journal of Epidemiology papers attest that Frost's personal evolution mirrored that of the emerging "early" epidemiology: The scope of epidemiology extended beyond the study of epidemics of acute infectious diseases, and rigorous comparative study designs and their associated quantitative methods came to light.

Snippets From the Past: The Evolution of Wade Hampton Frost's Epidemiology as Viewed From the American Journal of Hygiene/Epidemiology

PubMed Central

Morabia, Alfredo

2013-01-01

Wade Hampton Frost, who was a Professor of Epidemiology at Johns Hopkins University from 1919 to 1938, spurred the development of epidemiologic methods. His 6 publications in the American Journal of Hygiene, which later became the American Journal of Epidemiology, comprise a 1928 Cutter lecture on a theory of epidemics, a survey-based study of tonsillectomy and immunity to Corynebacterium diphtheriae (1931), 2 papers from a longitudinal study of the incidence of minor respiratory diseases (1933 and 1935), an attack rate ratio analysis of the decline of diphtheria in Baltimore (1936), and a 1936 lecture on the age, time, and cohort analysis of tuberculosis mortality. These 6 American Journal of Hygiene /American Journal of Epidemiology papers attest that Frost's personal evolution mirrored that of the emerging “early” epidemiology: The scope of epidemiology extended beyond the study of epidemics of acute infectious diseases, and rigorous comparative study designs and their associated quantitative methods came to light. PMID:24022889

THE 1998 BALTIMORE PARTICULATE MATTER EPIDEMIOLOGY-EXPOSURE STUDY: PART 2-PERSONAL EXPOSURE ASSESSMENT ASSOCIATED WITH AN ELDERLY STUDY POPULATION

EPA Science Inventory

An integrated epidemiological-exposure panel study was conducted during the summer of 1998 which focused upon establishing relationships between potential human exposures to particulate matter (PM) and related co-pollutants with detectable health effects. The study design incor...

Advances in spatial epidemiology and geographic information systems.

PubMed

Kirby, Russell S; Delmelle, Eric; Eberth, Jan M

2017-01-01

The field of spatial epidemiology has evolved rapidly in the past 2 decades. This study serves as a brief introduction to spatial epidemiology and the use of geographic information systems in applied research in epidemiology. We highlight technical developments and highlight opportunities to apply spatial analytic methods in epidemiologic research, focusing on methodologies involving geocoding, distance estimation, residential mobility, record linkage and data integration, spatial and spatio-temporal clustering, small area estimation, and Bayesian applications to disease mapping. The articles included in this issue incorporate many of these methods into their study designs and analytical frameworks. It is our hope that these studies will spur further development and utilization of spatial analysis and geographic information systems in epidemiologic research. Copyright © 2016 Elsevier Inc. All rights reserved.

INTEGRATING EPIDEMIOLOGY AND TOXICOLOGY IN NEUROTOXICITY RISK ASSESSMENT.

EPA Science Inventory

This manuscript provides an overview of the use of data from toxicology and epidemiology studies for neurotoxicity risk assessment. Parameters such as the use of subjects, study designs, exposures, and measured outcomes are compared and contrasted. The main concern for use of d...

Geometrically Evident: Framing Studies Using the Graphic Appraisal Tool for Epidemiology (GATE)

ERIC Educational Resources Information Center

Martin, Andres; Srihari, Vinod

2006-01-01

Educators in evidence-based medicine (EBM) have noted that the core set of epidemiological concepts outlined in standard sources are sometimes put to use as oversimplified checklists for the appraisal of research reports. In this article, the authors present the Graphic Appraisal Tool for Epidemiology which was designed as a way combat, by visual…

The Changing Epidemiology of Autism

ERIC Educational Resources Information Center

Fombonne, Eric

2005-01-01

This article reviews epidemiological studies of autism and related disorders. Study designs and sample characteristics are summarized. Currently, conservative prevalence estimates are: 13/10000 for autistic disorder, 21/10000 for pervasive developmental disorders not otherwise specified, 2.6/10000 for Asperger disorder, and 2/100000 for childhood…

A Data Base Management System for Clinical and Epidemiologic Studies In Systemic Lupus Erythematosus: Design and Maintenance

PubMed Central

Kosmides, Victoria S.; Hochberg, Marc C.

1984-01-01

This report describes the development, design specifications, features and implementation of a data base management system (DBMS) for clinical and epidemiologic studies in SLE. The DBMS is multidimensional with arrays formulated across patients, studies and variables. The major impact of this DBMS has been to increase the efficiency of managing and analyzing vast amounts of clinical and laboratory data and, as a result, to allow for continued growth in research productivity in areas related to SLE.

Epidemiology and Clinical Research Design, Part 2: Principles.

PubMed

Manja, Veena; Lakshminrusimha, Satyan

This is the third article covering core knowledge in scholarly activities for neonatal physicians. In this article, we discuss various principles of epidemiology and clinical research design. A basic knowledge of these principles is necessary for conducting clinical research and for proper interpretation of studies. This article reviews bias and confounding, causation, incidence and prevalence, decision analysis, cost-effectiveness, sensitivity analysis, and measurement.

Methodological considerations, such as directed acyclic graphs, for studying "acute on chronic" disease epidemiology: chronic obstructive pulmonary disease example.

PubMed

Tsai, Chu-Lin; Camargo, Carlos A

2009-09-01

Acute exacerbations of chronic disease are ubiquitous in clinical medicine, and thus far, there has been a paucity of integrated methodological discussion on this phenomenon. We use acute exacerbations of chronic obstructive pulmonary disease as an example to emphasize key epidemiological and statistical issues for this understudied field in clinical epidemiology. Directed acyclic graphs are a useful epidemiological tool to explain the differential effects of risk factor on health outcomes in studies of acute and chronic phases of disease. To study the pathogenesis of acute exacerbations of chronic disease, case-crossover design and time-series analysis are well-suited study designs to differentiate acute and chronic effect. Modeling changes over time and setting appropriate thresholds are important steps to separate acute from chronic phases of disease in serial measurements. In statistical analysis, acute exacerbations are recurrent events, and some individuals are more prone to recurrences than others. Therefore, appropriate statistical modeling should take into account intraindividual dependence. Finally, we recommend the use of "event-based" number needed to treat (NNT) to prevent a single exacerbation instead of traditional patient-based NNT. Addressing these methodological challenges will advance research quality in acute on chronic disease epidemiology.

Introduction to the use of regression models in epidemiology.

PubMed

Bender, Ralf

2009-01-01

Regression modeling is one of the most important statistical techniques used in analytical epidemiology. By means of regression models the effect of one or several explanatory variables (e.g., exposures, subject characteristics, risk factors) on a response variable such as mortality or cancer can be investigated. From multiple regression models, adjusted effect estimates can be obtained that take the effect of potential confounders into account. Regression methods can be applied in all epidemiologic study designs so that they represent a universal tool for data analysis in epidemiology. Different kinds of regression models have been developed in dependence on the measurement scale of the response variable and the study design. The most important methods are linear regression for continuous outcomes, logistic regression for binary outcomes, Cox regression for time-to-event data, and Poisson regression for frequencies and rates. This chapter provides a nontechnical introduction to these regression models with illustrating examples from cancer research.

The Prevention of Schizophrenia—What Can We Learn From Eco-Epidemiology?

PubMed Central

Kirkbride, James B.; Jones, Peter B.

2011-01-01

The search for the causes of schizophrenia has predominantly originated from 2 research paradigms; genetics and epidemiology. While each approach has made important contributions to etiological understanding, neither has fully resolved the exact milieu of risk factors for schizophrenia, and there is growing recognition that several pathways to the onset of such disorders may exist. Eco-epidemiology offers an integrative framework to study schizophrenia etiology, incorporating multiple, interactive levels of causation, including genetic, epigenetic, individual, familial, community, and societal domains over the life course. In this article, we review the current evidence base, through the lens of eco-epidemiology, to determine whether it warrants the design and implementation of putative prevention strategies for schizophrenia. We argue that while there are potentially large public health gains available, we do not currently have sufficient empirical data to design effective prevention strategies. It will be important for the research community to more fully elucidate the likely multifactorial, multilevel, polygenetic, and eco-epidemiological basis of schizophrenia before we can design useful prevention strategies. We conclude by speculating on the forms effective strategies might take. PMID:20974748

Translational Epidemiology in Psychiatry

PubMed Central

Weissman, Myrna M.; Brown, Alan S.; Talati, Ardesheer

2012-01-01

Translational research generally refers to the application of knowledge generated by advances in basic sciences research translated into new approaches for diagnosis, prevention, and treatment of disease. This direction is called bench-to-bedside. Psychiatry has similarly emphasized the basic sciences as the starting point of translational research. This article introduces the term translational epidemiology for psychiatry research as a bidirectional concept in which the knowledge generated from the bedside or the population can also be translated to the benches of laboratory science. Epidemiologic studies are primarily observational but can generate representative samples, novel designs, and hypotheses that can be translated into more tractable experimental approaches in the clinical and basic sciences. This bedside-to-bench concept has not been explicated in psychiatry, although there are an increasing number of examples in the research literature. This article describes selected epidemiologic designs, providing examples and opportunities for translational research from community surveys and prospective, birth cohort, and family-based designs. Rapid developments in informatics, emphases on large sample collection for genetic and biomarker studies, and interest in personalized medicine—which requires information on relative and absolute risk factors—make this topic timely. The approach described has implications for providing fresh metaphors to communicate complex issues in interdisciplinary collaborations and for training in epidemiology and other sciences in psychiatry. PMID:21646577

Epidemiology and Clinical Research Design, Part 2: Principles

PubMed Central

Manja, Veena; Lakshminrusimha, Satyan

2015-01-01

This is the third article covering core knowledge in scholarly activities for neonatal physicians. In this article, we discuss various principles of epidemiology and clinical research design. A basic knowledge of these principles is necessary for conducting clinical research and for proper interpretation of studies. This article reviews bias and confounding, causation, incidence and prevalence, decision analysis, cost-effectiveness, sensitivity analysis, and measurement. PMID:26236171

THE NATIONAL EPIDEMIOLOGICAL AND ENVIRONMENTAL ASSESSMENT OF RECREATIONAL WATERS: RESULTS FROM THE FIRST SUMMER OF FULL-SCALE STUDIES

EPA Science Inventory

Introduction

The National Epidemiological and Environmental Assessment of Recreational Waters (NEEAR) is a multi-year study of recreational water conducted by the United States Environmental Protection Agency and the Centers for Disease Control and Prevention (CDC), design...

THE NATIONAL EPIDEMIOLOGICAL AND ENVIRONMENTAL ASSESSMENT OF RECREATIONAL WATERS: RESULTS FROM THE FIRST SUMMER FULL-SCALE STUDIES

EPA Science Inventory

Introduction

The National Epidemiological and Environmental Assessment of Recreational Waters (NEEAR) is a multi-year study of recreational water conducted by the United States Environmental Protection Agency and the Centers for Disease Control and Prevention (CDC), design...

DESIGN OF EXPOSURE MEASUREMENTS FOR EPIDEMIOLOGIC STUDIES

EPA Science Inventory

This presentation will describe the following items: (1) London daily air pollution and deaths that demonstrate how time series epidemiology can indicate that air pollution caused death; (2) Sophisticated statistical models required to establish this relationship for lower pollut...

Challenges and Opportunities for Occupational Epidemiology in the Twenty-first Century.

PubMed

Stayner, L T; Collins, J J; Guo, Y L; Heederik, D; Kogevinas, M; Steenland, K; Wesseling, C; Demers, P A

2017-09-01

There are many opportunities and challenges for conducting occupational epidemiologic studies today. In this paper, we summarize the discussion of a symposium held at the Epidemiology in Occupational Health (EPICOH) conference, Chicago 2014, on challenges for occupational epidemiology in the twenty-first century. The increasing number of publications and attendance at our conferences suggests that worldwide interest in occupational epidemiology has been growing. There are clearly abundant opportunities for new research in occupational epidemiology. Areas ripe for further work include developing improved methods for exposure assessment, statistical analysis, studying migrant workers and other vulnerable populations, the use of biomarkers, and new hazards. Several major challenges are also discussed such as the rapidly changing nature and location of work, lack of funding, and political/legal conflicts. As long as work exists there will be occupational diseases that demand our attention, and a need for epidemiologic studies designed to characterize these risks and to support the development of preventive strategies. Despite the challenges and given the important past contribution in this field, we are optimistic about the importance and continued vitality of the research field of occupational epidemiology.

A Course in Medical Research Study Design and Analysis.

ERIC Educational Resources Information Center

Linskey, Mark E.; And Others

1987-01-01

A course to familiarize medical students with the principles of good medical research study design and analysis focuses on three types of studies: clinical trials, laboratory science, and epidemiology and biostatistics. (MSE)

Foodborne outbreak simulation to teach field epidemiology: the Moroccan Field Epidemiology Training Program.

PubMed

Jroundi, Imane; Belarbi, Abdellatif

2016-11-01

Morocco in 2010 launched a new field epidemiology training program to enhance the skills of health professionals in charge of epidemiological surveillance and to investigate outbreaks; including foodborne diseases that represent a very substantial burden of disease. To apply an active learning method to teach outbreak investigation within a controled environment for field epidemiology trainees program at the Moroccan National school of public Health. A scenario describing digestive symptoms evoking a restaurant-associated foodborne outbreak that would affect the school staff was designed for the residents to investigate, to assess their organizational capacity and application of all stages of epidemiological investigation. Nine Residents applied study design, database management and statistical analysis to investigate the foodborne outbreak, to estimate attack rates, classify cases and controls, to identify the contaminated foods and pathogens and to issue preventive recommendations for the control and the prevention of further transmission. The overall resident's satisfaction of the learning method was 67%. A simulation of an outbreak investigation within an academic setting is an active learning method to be used in the curriculum for introducing the residents on field epidemiology program to the principles and practices of outbreak investigation before their implication in a real situation.

[Prevalence of the Diabetic Retinopathy and Genetic Factors Significance in the Development of Diabetic Retinopathy in Patients with Diabetes Mellitus type I and II in Slovakia (DIARET SK study). Overview of Actual Findings and Design of the Epidemiological DIARET SK Study].

PubMed

Krásnik, V; Štefaničková, J; Fabková, J; Bucková, D; Helbich, M

2015-09-01

Diabetic retinopathy (DR) is the second most common microvascular complication and the most common cause of blindness in patients with diabetes mellitus (DM). Despite the ongoing research, the findings of diabetic retinopathy epidemiological and risk factors are, until now, not consistent. More finding may be revealed by epidemiological studies, consistently mapping DR epidemiology under the current possibilities of investigations and treatment of the DM. DIARET SK Study, with 5 000 enrolled patients with diabetes mellitus in the Slovak Republic, is, until now, the largest epidemiological study to set the prevalence of diabetic retinopathy. The primary aim is to establish the prevalence of diabetic retinopathy in patients with diabetes mellitus type I and II, according to the duration of the disease. The secondary aim is to establish prevalence of the different stages of the DR and diabetic macular edema (DME) and analysis of the risk factors influence. Included are patients with DM type I and II regardless to the ocular complications history and the period of DM duration. Each enrolled patient has both complex diabetic and ophthalmic examinations.Projects to establish DR prevalence: Tens of projects concerned with diabetic retinopathy epidemiology with different approaches to establish the prevalence and with different patients population. Results from different studies vary significantly (from 12.3 % to 66.9 %). The results depend on the design of the study and the patients recruitment, used examination methods, specific patients population with regard to the geography, prevalence of risk factors, period of diabetes duration, glycated hemoglobin (HbA1C) level, blood pressure, and is higher in type I diabetic patients. The most accurate results are from population epidemiological studies with well-controlled patient recruitment and uniform complex examination that are similar to the DIARET SK study. The DIARET SK study represents the largest epidemiological study to establish the prevalence of the diabetic retinopathy in patients with DM type I and II. Thanks to the quality design, similar to the already published studies, but with larger number of patients and newest examinations methods, the DIARET SK study has the aspiration to obtain the most accurate up to date data of diabetic retinopathy prevalence and risk factors influence to its outbreak. The patients recruitment started in February 2015. The expected date of patients recruitment termination is in the end of the year 2015, and the data analysis in 2016.

Epidemiological designs for vaccine safety assessment: methods and pitfalls.

PubMed

Andrews, Nick

2012-09-01

Three commonly used designs for vaccine safety assessment post licensure are cohort, case-control and self-controlled case series. These methods are often used with routine health databases and immunisation registries. This paper considers the issues that may arise when designing an epidemiological study, such as understanding the vaccine safety question, case definition and finding, limitations of data sources, uncontrolled confounding, and pitfalls that apply to the individual designs. The example of MMR and autism, where all three designs have been used, is presented to help consider these issues. Copyright © 2011 The International Alliance for Biological Standardization. Published by Elsevier Ltd. All rights reserved.

Experimental design and quantitative analysis of microbial community multiomics.

PubMed

Mallick, Himel; Ma, Siyuan; Franzosa, Eric A; Vatanen, Tommi; Morgan, Xochitl C; Huttenhower, Curtis

2017-11-30

Studies of the microbiome have become increasingly sophisticated, and multiple sequence-based, molecular methods as well as culture-based methods exist for population-scale microbiome profiles. To link the resulting host and microbial data types to human health, several experimental design considerations, data analysis challenges, and statistical epidemiological approaches must be addressed. Here, we survey current best practices for experimental design in microbiome molecular epidemiology, including technologies for generating, analyzing, and integrating microbiome multiomics data. We highlight studies that have identified molecular bioactives that influence human health, and we suggest steps for scaling translational microbiome research to high-throughput target discovery across large populations.

The Schisto Track: A System for Gathering and Monitoring Epidemiological Surveys by Connecting Geographical Information Systems in Real Time

PubMed Central

2014-01-01

Background Using the Android platform as a notification instrument for diseases and disorders forms a new alternative for computerization of epidemiological studies. Objective The objective of our study was to construct a tool for gathering epidemiological data on schistosomiasis using the Android platform. Methods The developed application (app), named the Schisto Track, is a tool for data capture and analysis that was designed to meet the needs of a traditional epidemiological survey. An initial version of the app was finished and tested in both real situations and simulations for epidemiological surveys. Results The app proved to be a tool capable of automation of activities, with data organization and standardization, easy data recovery (to enable interfacing with other systems), and totally modular architecture. Conclusions The proposed Schisto Track is in line with worldwide trends toward use of smartphones with the Android platform for modeling epidemiological scenarios. PMID:25099881

Information content of household-stratified epidemics.

PubMed

Kinyanjui, T M; Pellis, L; House, T

2016-09-01

Household structure is a key driver of many infectious diseases, as well as a natural target for interventions such as vaccination programs. Many theoretical and conceptual advances on household-stratified epidemic models are relatively recent, but have successfully managed to increase the applicability of such models to practical problems. To be of maximum realism and hence benefit, they require parameterisation from epidemiological data, and while household-stratified final size data has been the traditional source, increasingly time-series infection data from households are becoming available. This paper is concerned with the design of studies aimed at collecting time-series epidemic data in order to maximize the amount of information available to calibrate household models. A design decision involves a trade-off between the number of households to enrol and the sampling frequency. Two commonly used epidemiological study designs are considered: cross-sectional, where different households are sampled at every time point, and cohort, where the same households are followed over the course of the study period. The search for an optimal design uses Bayesian computationally intensive methods to explore the joint parameter-design space combined with the Shannon entropy of the posteriors to estimate the amount of information in each design. For the cross-sectional design, the amount of information increases with the sampling intensity, i.e., the designs with the highest number of time points have the most information. On the other hand, the cohort design often exhibits a trade-off between the number of households sampled and the intensity of follow-up. Our results broadly support the choices made in existing epidemiological data collection studies. Prospective problem-specific use of our computational methods can bring significant benefits in guiding future study designs. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.

Mendelian randomization in nutritional epidemiology

PubMed Central

Qi, Lu

2013-01-01

Nutritional epidemiology aims to identify dietary and lifestyle causes for human diseases. Causality inference in nutritional epidemiology is largely based on evidence from studies of observational design, and may be distorted by unmeasured or residual confounding and reverse causation. Mendelian randomization is a recently developed methodology that combines genetic and classical epidemiological analysis to infer causality for environmental exposures, based on the principle of Mendel’s law of independent assortment. Mendelian randomization uses genetic variants as proxiesforenvironmentalexposuresofinterest.AssociationsderivedfromMendelian randomization analysis are less likely to be affected by confounding and reverse causation. During the past 5 years, a body of studies examined the causal effects of diet/lifestyle factors and biomarkers on a variety of diseases. The Mendelian randomization approach also holds considerable promise in the study of intrauterine influences on offspring health outcomes. However, the application of Mendelian randomization in nutritional epidemiology has some limitations. PMID:19674341

Risk factors and study designs used in research of youths' suicide behaviour-an epidemiological discussion with focus on level of evidence.

PubMed

Christiansen, Erik; Larsen, Kim Juul; Agerbo, Esben; Bilenberg, Niels; Stenager, Elsebeth

2014-11-01

Abstract Introduction: Many different epidemiology study designs have been used to analyse risk factors for suicide behaviour. The purpose of this study was to obtain an insight into the current study design used in research on youths' risk factors for suicide behaviour and to rank the studies according to level of evidence (LoE). We searched PubMed and psycINFO in order to identify relevant individual studies. We included 36 studies of children and youth on suicidal behaviour and ideation-many rank low on LoE. For suicide, cohort design was often used, and mental illness (depression, substance abuse and severity of mental illness) was the most common risk factor. Cohort studies are ranked 2b, which is high according to LoE. For suicide attempts, survey was often used, and psychopathology, substance abuse and being exposed to suicidal behaviour were the most common risk factors. For suicidal ideation, survey was the only design used, and substance abuse and psychopathology the most common risk factors. Surveys are ranked 4, which are low according to LoE. Many risk factors were broad and unspecific, and standard definitions of outcome and exposure were rarely used. A good study of risk factors for suicidal behaviour would need a high LoE, as a high-powered longitudinal epidemiological study (cohort or case-control) of very specific risk factors. The factors would have high prevention potential, compared with more broad and unspecific risk factors, to which many people are exposed. We would recommend a cohort design (in high-risk populations) or a case-control design to identify risk factors, using clinical and/or register data instead of self-reported information, reporting adjusted estimates and using standard definition of suicidal outcome and risk factors.

Los Alamos National Laboratory: A guide to records series supporting epidemiologic studies conducted for the Department of Energy

DOE Office of Scientific and Technical Information (OSTI.GOV)

NONE

1997-01-01

The purpose of this guide is to describe each series of records that pertains to the epidemiologic studies conducted by the Epidemiology Section of the Occupational Medicine Group (ESH-2) at the Department of Energy`s (DOE) Los Alamos National Laboratory (LANL) in Los Alamos, New Mexico. The records described in this guide relate to occupational studies performed by the Epidemiology Section, including those pertaining to workers at LANL, Mound Plant, Oak Ridge Reservation, Pantex Plant, Rocky Flats Plant, and Savannah River Site. Also included are descriptions of other health-related records generated or collected by the Epidemiology Section and a small setmore » of records collected by the Industrial Hygiene and Safety Group. This guide is not designed to describe the universe of records generated by LANL which may be used for epidemiologic studies of the LANL work force. History Associates Incorporated (HAI) prepared this guide as part of its work as the support services contractor for DOE`s Epidemiologic Records Inventory Project. This introduction briefly describes the Epidemiologic Records Inventory Project, HAI`s role in the project, the history of LANL the history and functions of LANL`s Health Division and Epidemiology Section, and the various epidemiologic studies performed by the Epidemiology Section. It provides information on the methodology that HAI used to inventory and describe records housed in the offices of the LANL Epidemiology Section in Technical Area 59 and at the LANL Records Center. Other topics include the methodology used to produce the guide, the arrangement of the detailed record series descriptions, and information concerning access to records repositories.« less

The healthy men study: design and recruitment considerations for environmental epidemiologic studies in male reproductive health

EPA Science Inventory

Study Objective: To describe study conduct and response and participant characteristics. Design: Prospective cohort study. Setting: Participants were male partners of women enrolled in a community-based study of drinking water disinfection by-products and pregnancy healt...

16 CFR 1000.26 - Directorate for Epidemiology.

Code of Federal Regulations, 2011 CFR

2011-01-01

.... In addition, staff in the Hazard Analysis Division design special studies, design and analyze data from experiments for testing of consumer products, and provide statistical expertise and advice to...

16 CFR 1000.26 - Directorate for Epidemiology.

Code of Federal Regulations, 2012 CFR

2012-01-01

.... In addition, staff in the Hazard Analysis Division design special studies, design and analyze data from experiments for testing of consumer products, and provide statistical expertise and advice to...

16 CFR 1000.26 - Directorate for Epidemiology.

Code of Federal Regulations, 2014 CFR

2014-01-01

.... In addition, staff in the Hazard Analysis Division design special studies, design and analyze data from experiments for testing of consumer products, and provide statistical expertise and advice to...

Causality and causal inference in epidemiology: the need for a pluralistic approach.

PubMed

Vandenbroucke, Jan P; Broadbent, Alex; Pearce, Neil

2016-12-01

Causal inference based on a restricted version of the potential outcomes approach reasoning is assuming an increasingly prominent place in the teaching and practice of epidemiology. The proposed concepts and methods are useful for particular problems, but it would be of concern if the theory and practice of the complete field of epidemiology were to become restricted to this single approach to causal inference. Our concerns are that this theory restricts the questions that epidemiologists may ask and the study designs that they may consider. It also restricts the evidence that may be considered acceptable to assess causality, and thereby the evidence that may be considered acceptable for scientific and public health decision making. These restrictions are based on a particular conceptual framework for thinking about causality. In Section 1, we describe the characteristics of the restricted potential outcomes approach (RPOA) and show that there is a methodological movement which advocates these principles, not just for solving particular problems, but as ideals for which epidemiology as a whole should strive. In Section 2, we seek to show that the limitation of epidemiology to one particular view of the nature of causality is problematic. In Section 3, we argue that the RPOA is also problematic with regard to the assessment of causality. We argue that it threatens to restrict study design choice, to wrongly discredit the results of types of observational studies that have been very useful in the past and to damage the teaching of epidemiological reasoning. Finally, in Section 4 we set out what we regard as a more reasonable 'working hypothesis' as to the nature of causality and its assessment: pragmatic pluralism. © The Author 2016. Published by Oxford University Press on behalf of the International Epidemiological Association.

[Strengthening the methodology of study designs in scientific researches].

PubMed

Ren, Ze-qin

2010-06-01

Many problems in study designs have affected the validity of scientific researches seriously. We must understand the methodology of research, especially clinical epidemiology and biostatistics, and recognize the urgency in selection and implement of right study design. Thereafter we can promote the research capability and improve the overall quality of scientific researches.

16 CFR § 1000.26 - Directorate for Epidemiology.

Code of Federal Regulations, 2013 CFR

2013-01-01

.... In addition, staff in the Hazard Analysis Division design special studies, design and analyze data from experiments for testing of consumer products, and provide statistical expertise and advice to...

Environmental Viral Metagenomics Analyses in Aquaculture: Applications in Epidemiology and Disease Control

PubMed Central

Munang’andu, Hetron M.

2016-01-01

Studies on the epidemiology of viral diseases in aquaculture have for a long time depended on isolation of viruses from infected aquatic organisms. The role of aquatic environments in the epidemiology of viral diseases in aquaculture has not been extensively expounded mainly because of the lack of appropriate tools for environmental studies on aquatic viruses. However, the upcoming of metagenomics analyses opens great avenues in which environmental samples can be used to study the epidemiology of viral diseases outside their host species. Hence, in this review I have shown that epidemiological factors that influence the composition of viruses in different aquatic environments include ecological factors, anthropogenic activities and stocking densities of cultured organisms based on environmental metagenomics studies carried out this far. Ballast water transportation and global trade of aquatic organisms are the most common virus dispersal process identified this far. In terms of disease control for outdoor aquaculture systems, baseline data on viruses found in different environments intended for aquaculture use can be obtained to enable the design of effective disease control strategies. And as such, high-risk areas having a high specter of pathogenic viruses can be identified as an early warning system. As for the control of viral diseases for indoor recirculation aquaculture systems (RAS), the most effective disinfection methods able to eliminate pathogenic viruses from water used in RAS can be identified. Overall, the synopsis I have put forth in this review shows that environmental samples can be used to study the epidemiology of viral diseases in aquaculture using viral metagenomics analysis as an overture for the design of rational disease control strategies. PMID:28018317

Designing Epidemiology Studies to Determine the Incidence and Prevalence of Encapsulating Peritoneal Sclerosis (EPS).

PubMed

Nitsch, Dorothea; Davenport, Andrew

2015-12-01

The reported incidence and prevalence of encapsulating peritoneal sclerosis (EPS) varies markedly between North America, Europe, Japan, and Australia. Although this could reflect differences in clinical practice patterns and access to transplantation as there is no current test for early detection, and some patients may present many years after discontinuation of peritoneal dialysis (PD), there are concerns about under-reporting, particularly for those with milder forms. Currently, only PD vintage has been identified as a significant risk factor for developing EPS, although some patients can develop EPS within months of starting PD. As such, there is a need for epidemiological studies to determine the incidence and prevalence of EPS to allow for patient education and counselling in terms of dialysis modality choice and length of treatment. In addition, carefully designed epidemiological studies could potentially allow for the identification of risk factors and bio-markers that could then be used to identify patients at increased risk of developing EPS in the future. Typically, studies to date have been underpowered with inadequate longitudinal follow-up. We review the different types of epidemiological studies and provide information as to the number of patients to be recruited and the duration of follow-up required to determine the incidence and prevalence of EPS. Copyright © 2015 International Society for Peritoneal Dialysis.

Mental illness and reduction of gun violence and suicide: bringing epidemiologic research to policy.

PubMed

Swanson, Jeffrey W; McGinty, E Elizabeth; Fazel, Seena; Mays, Vickie M

2015-05-01

This article describes epidemiologic evidence concerning risk of gun violence and suicide linked to psychiatric disorders, in contrast to media-fueled public perceptions of the dangerousness of mentally ill individuals, and evaluates effectiveness of policies and laws designed to prevent firearms injury and mortality associated with serious mental illnesses and substance use disorders. Research concerning public attitudes toward persons with mental illness is reviewed and juxtaposed with evidence from benchmark epidemiologic and clinical studies of violence and mental illness and of the accuracy of psychiatrists' risk assessments. Selected policies and laws designed to reduce gun violence in relation to mental illness are critically evaluated; evidence-based policy recommendations are presented. Media accounts of mass shootings by disturbed individuals galvanize public attention and reinforce popular belief that mental illness often results in violence. Epidemiologic studies show that the large majority of people with serious mental illnesses are never violent. However, mental illness is strongly associated with increased risk of suicide, which accounts for over half of US firearms-related fatalities. Policymaking at the interface of gun violence prevention and mental illness should be based on epidemiologic data concerning risk to improve the effectiveness, feasibility, and fairness of policy initiatives. Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.

Mental illness and reduction of gun violence and suicide: bringing epidemiologic research to policy

PubMed Central

Swanson, Jeffrey W.; McGinty, E. Elizabeth; Fazel, Seena; Mays, Vickie M.

2015-01-01

Purpose This article describes epidemiologic evidence concerning risk of gun violence and suicide linked to psychiatric disorders, in contrast to media-fueled public perceptions of the dangerousness of mentally ill individuals, and evaluates effectiveness of policies and laws designed to prevent firearms injury and mortality associated with serious mental illnesses and substance use disorders. Methods Research concerning public attitudes toward persons with mental illness is reviewed and juxtaposed with evidence from benchmark epidemiologic and clinical studies of violence and mental illness and of the accuracy of psychiatrists' risk assessments. Selected policies and laws designed to reduce gun violence in relation to mental illness are critically evaluated; evidence-based policy recommendations are presented. Results Media accounts of mass shootings by disturbed individuals galvanize public attention and reinforce popular belief that mental illness often results in violence. Epidemiologic studies show that the large majority of people with serious mental illnesses are never violent. However, mental illness is strongly associated with increased risk of suicide, which accounts for over half of US firearms–related fatalities. Conclusions Policymaking at the interface of gun violence prevention and mental illness should be based on epidemiologic data concerning risk to improve the effectiveness, feasibility, and fairness of policy initiatives. PMID:24861430

Immortal time bias in pharmaco-epidemiology.

PubMed

Suissa, Samy

2008-02-15

Immortal time is a span of cohort follow-up during which, because of exposure definition, the outcome under study could not occur. Bias from immortal time was first identified in the 1970s in epidemiology in the context of cohort studies of the survival benefit of heart transplantation. It recently resurfaced in pharmaco-epidemiology, with several observational studies reporting that various medications can be extremely effective at reducing morbidity and mortality. These studies, while using different cohort designs, all involved some form of immortal time and the corresponding bias. In this paper, the author describes various cohort study designs leading to this bias, quantifies its magnitude under different survival distributions, and illustrates it by using data from a cohort of lung cancer patients. The author shows that for time-based, event-based, and exposure-based cohort definitions, the bias in the rate ratio resulting from misclassified or excluded immortal time increases proportionately to the duration of immortal time. The bias is more pronounced with a decreasing hazard function for the outcome event, as illustrated with the Weibull distribution compared with a constant hazard from the exponential distribution. In conclusion, observational studies of drug benefit in which computerized databases are used must be designed and analyzed properly to avoid immortal time bias.

Sudden cardiac death in haemodialysis: clinical epidemiology and mechanisms.

PubMed

Banerjee, Debasish

Sudden cardiac death, which causes premature loss of lives on haemodialysis of the elderly, youths and even children; cannot be prevented, because the aetiology is poorly understood and effective interventions are yet unknown. Improving our knowledge of mechanisms causing sudden cardiac death in haemodialysis patients may help us to design better interventions; and clinical epidemiology of sudden cardiac death could be an important tool to further guide human and animal studies. This review researches the clinical epidemiology of sudden cardiac death to suggest possible mechanisms, although they require further studies. The research shows how traditional cardiovascular risk factors such as age, diabetes and smoking have an impact; non-traditional risk factors such as inflammation, mineral-bone disease and even uraemia itself have higher impact; and how cardiac structural, functional and electrocardiographic markers predict sudden cardiac death in dialysis patients. More in-depth human and animal studies, guided with existing knowledge, are necessary to better understand the mechanisms and design successful interventions. Copyright © 2016 Elsevier Inc. All rights reserved.

Epidemiology of non-submersion injuries in aquatic sporting and recreational activities.

PubMed

Chalmers, David; Morrison, Luke

2003-01-01

Although the issues of drowning and near-drowning in aquatic sporting and recreational activities receive considerable attention in the epidemiological literature, there is not a recognised literature on non-submersion injuries occurring in these activities. This review draws together the epidemiological literature on non-submersion injuries and describes the incidence, nature and causes of these injuries, common risk factors, and strategies for prevention. Activities covered by the review include swimming, diving, boating, surf sports, fishing, water polo and water sliding. For most activities there is a dearth of good quality descriptive studies, with most involving cases-series designs and few providing estimates of incidence. Inconsistencies in inclusion criteria and the reporting of incidence rates makes comparisons within and between activities difficult. Incidence rates were identified for most activities and in general the incidence of injury was low, especially for more serious injury. However, some activities were associated with severely disabling injury, such as spinal cord injury (diving) and amputation (from propeller strikes in water skiing and swimming). Only three studies reporting the significance of postulated risk factors were identified. Lack of knowledge about the water being entered and alcohol consumption are significant risk factors in recreational diving; increased blood alcohol concentrations were reported to increase the risk of death in boating; and obesity and tandem riding were reported to increase the risk of injury on public water slides. Few evaluations of preventive measures were identified. Two studies reported reductions in the incidence of water slide injuries following the introduction of design changes and supervision, but neither had a non-intervention comparison group. Improvements in swimming and diving skills were reported in three studies, but these were not designed to measure changes in the risk of injury.This review demonstrates that there is a need for well-designed epidemiological research on non-submersion injury in aquatic sporting and recreational activities. The first priority should be for studies designed to describe accurately the incidence, nature, severity and circumstances of these injuries, followed by research on the significance of postulated risk factors. Once this research has been undertaken, interventions targeted at reducing the incidence of injury in aquatic sporting and recreational activities can be designed and evaluated.

Association Between Cannabis and Psychosis: Epidemiologic Evidence.

PubMed

Gage, Suzanne H; Hickman, Matthew; Zammit, Stanley

2016-04-01

Associations between cannabis use and psychotic outcomes are consistently reported, but establishing causality from observational designs can be problematic. We review the evidence from longitudinal studies that have examined this relationship and discuss the epidemiologic evidence for and against interpreting the findings as causal. We also review the evidence identifying groups at particularly high risk of developing psychosis from using cannabis. Overall, evidence from epidemiologic studies provides strong enough evidence to warrant a public health message that cannabis use can increase the risk of psychotic disorders. However, further studies are required to determine the magnitude of this effect, to determine the effect of different strains of cannabis on risk, and to identify high-risk groups particularly susceptible to the effects of cannabis on psychosis. We also discuss complementary epidemiologic methods that can help address these questions. Copyright © 2016 Society of Biological Psychiatry. Published by Elsevier Inc. All rights reserved.

The ZInEP Epidemiology Survey: background, design and methods.

PubMed

Ajdacic-Gross, Vladeta; Müller, Mario; Rodgers, Stephanie; Warnke, Inge; Hengartner, Michael P; Landolt, Karin; Hagenmuller, Florence; Meier, Magali; Tse, Lee-Ting; Aleksandrowicz, Aleksandra; Passardi, Marco; Knöpfli, Daniel; Schönfelder, Herdis; Eisele, Jochen; Rüsch, Nicolas; Haker, Helene; Kawohl, Wolfram; Rössler, Wulf

2014-12-01

This article introduces the design, sampling, field procedures and instruments used in the ZInEP Epidemiology Survey. This survey is one of six ZInEP projects (Zürcher Impulsprogramm zur nachhaltigen Entwicklung der Psychiatrie, i.e. the "Zurich Program for Sustainable Development of Mental Health Services"). It parallels the longitudinal Zurich Study with a sample comparable in age and gender, and with similar methodology, including identical instruments. Thus, it is aimed at assessing the change of prevalence rates of common mental disorders and the use of professional help and psychiatric sevices. Moreover, the current survey widens the spectrum of topics by including sociopsychiatric questionnaires on stigma, stress related biological measures such as load and cortisol levels, electroencephalographic (EEG) and near-infrared spectroscopy (NIRS) examinations with various paradigms, and sociophysiological tests. The structure of the ZInEP Epidemiology Survey entails four subprojects: a short telephone screening using the SCL-27 (n of nearly 10,000), a comprehensive face-to-face interview based on the SPIKE (Structured Psychopathological Interview and Rating of the Social Consequences for Epidemiology: the main instrument of the Zurich Study) with a stratified sample (n = 1500), tests in the Center for Neurophysiology and Sociophysiology (n = 227), and a prospective study with up to three follow-up interviews and further measures (n = 157). In sum, the four subprojects of the ZInEP Epidemiology Survey deliver a large interdisciplinary database. Copyright © 2014 John Wiley & Sons, Ltd.

Epidemiology of Transfusion-Transmitted Infections Among Multi-Transfused Patients in Seven Hospitals in Peru

DTIC Science & Technology

2005-01-01

locate jcv Epidemiology of transfusion-transmitted infections among multi-transfused patients in seven hospitals in Peru 1 VA. Laguna-Torres a...and risk factors associated with TTIs among a sample of multi-transfused adult patients in Peru Study design: A cross- sectional multi-center study...was conducted across seven major hospitals in Peru fi’om February 2003 to September 2004 Self-reported behavior lntbrmatlon (medical procedures

Causality and causal inference in epidemiology: the need for a pluralistic approach

PubMed Central

Vandenbroucke, Jan P; Broadbent, Alex; Pearce, Neil

2016-01-01

Abstract Causal inference based on a restricted version of the potential outcomes approach reasoning is assuming an increasingly prominent place in the teaching and practice of epidemiology. The proposed concepts and methods are useful for particular problems, but it would be of concern if the theory and practice of the complete field of epidemiology were to become restricted to this single approach to causal inference. Our concerns are that this theory restricts the questions that epidemiologists may ask and the study designs that they may consider. It also restricts the evidence that may be considered acceptable to assess causality, and thereby the evidence that may be considered acceptable for scientific and public health decision making. These restrictions are based on a particular conceptual framework for thinking about causality. In Section 1, we describe the characteristics of the restricted potential outcomes approach (RPOA) and show that there is a methodological movement which advocates these principles, not just for solving particular problems, but as ideals for which epidemiology as a whole should strive. In Section 2, we seek to show that the limitation of epidemiology to one particular view of the nature of causality is problematic. In Section 3, we argue that the RPOA is also problematic with regard to the assessment of causality. We argue that it threatens to restrict study design choice, to wrongly discredit the results of types of observational studies that have been very useful in the past and to damage the teaching of epidemiological reasoning. Finally, in Section 4 we set out what we regard as a more reasonable ‘working hypothesis’ as to the nature of causality and its assessment: pragmatic pluralism. PMID:26800751

Important considerations for designing and reporting epidemiologic and clinical studies in dental traumatology.

PubMed

Andersson, Lars; Andreasen, Jens O

2011-08-01

The purpose of this article is to suggest important considerations for epidemiologic and clinical studies in the field of dental traumatology. The article is based on the authors' experiences from research in this field and editorial board work for the scientific journal Dental Traumatology. Examples are given of issues where development is important. The importance of planning ahead of the study and consulting with experts in other fields is emphasized. © 2011 John Wiley & Sons A/S.

Assessing the first wave of epidemiological studies of nanomaterial workers

NASA Astrophysics Data System (ADS)

Liou, Saou-Hsing; Tsai, Candace S. J.; Pelclova, Daniela; Schubauer-Berigan, Mary K.; Schulte, Paul A.

2015-10-01

The results of early animal studies of engineered nanomaterials (ENMs) and air pollution epidemiology suggest that it is important to assess the health of ENM workers. Initial epidemiological studies of workers' exposure to ENMs (<100 nm) are reviewed and characterized for their study designs, findings, and limitations. Of the 15 studies, 11 were cross-sectional, 4 were longitudinal (1 was both cross-sectional and longitudinal in design), and 1 was a descriptive pilot study. Generally, the studies used biologic markers as the dependent variables. All 11 cross-sectional studies showed a positive relationship between various biomarkers and ENM exposures. Three of the four longitudinal studies showed a negative relationship; the fourth showed positive findings after a 1-year follow-up. Each study considered exposure to ENMs as the independent variable. Exposure was assessed by mass concentration in 10 studies and by particle count in six studies. Six of them assessed both mass and particle concentrations. Some of the studies had limited exposure data because of inadequate exposure assessment. Generally, exposure levels were not very high in comparison to those in human inhalation chamber studies, but there were some exceptions. Most studies involved a small sample size, from 2 to 258 exposed workers. These studies represent the first wave of epidemiological studies of ENM workers. They are limited by small numbers of participants, inconsistent (and in some cases inadequate) exposure assessments, generally low exposures, and short intervals between exposure and effect. Still, these studies are a foundation for future work; they provide insight into where ENM workers are experiencing potentially adverse effects that might be related to ENM exposures.

Evidence-based decision-making in infectious diseases epidemiology, prevention and control: matching research questions to study designs and quality appraisal tools

PubMed Central

2014-01-01

Background The Project on a Framework for Rating Evidence in Public Health (PRECEPT) was initiated and is being funded by the European Centre for Disease Prevention and Control (ECDC) to define a methodology for evaluating and grading evidence and strength of recommendations in the field of public health, with emphasis on infectious disease epidemiology, prevention and control. One of the first steps was to review existing quality appraisal tools (QATs) for individual research studies of various designs relevant to this area, using a question-based approach. Methods Through team discussions and expert consultations, we identified 20 relevant types of public health questions, which were grouped into six domains, i.e. characteristics of the pathogen, burden of disease, diagnosis, risk factors, intervention, and implementation of intervention. Previously published systematic reviews were used and supplemented by expert consultation to identify suitable QATs. Finally, a matrix was constructed for matching questions to study designs suitable to address them and respective QATs. Key features of each of the included QATs were then analyzed, in particular in respect to its intended use, types of questions and answers, presence/absence of a quality score, and if a validation was performed. Results In total we identified 21 QATs and 26 study designs, and matched them. Four QATs were suitable for experimental quantitative study designs, eleven for observational quantitative studies, two for qualitative studies, three for economic studies, one for diagnostic test accuracy studies, and one for animal studies. Included QATs consisted of six to 28 items. Six of the QATs had a summary quality score. Fourteen QATs had undergone at least one validation procedure. Conclusions The results of this methodological study can be used as an inventory of potentially relevant questions, appropriate study designs and QATs for researchers and authorities engaged with evidence-based decision-making in infectious disease epidemiology, prevention and control. PMID:24886571

Evidence-based decision-making in infectious diseases epidemiology, prevention and control: matching research questions to study designs and quality appraisal tools.

PubMed

Harder, Thomas; Takla, Anja; Rehfuess, Eva; Sánchez-Vivar, Alex; Matysiak-Klose, Dorothea; Eckmanns, Tim; Krause, Gérard; de Carvalho Gomes, Helena; Jansen, Andreas; Ellis, Simon; Forland, Frode; James, Roberta; Meerpohl, Joerg J; Morgan, Antony; Schünemann, Holger; Zuiderent-Jerak, Teun; Wichmann, Ole

2014-05-21

The Project on a Framework for Rating Evidence in Public Health (PRECEPT) was initiated and is being funded by the European Centre for Disease Prevention and Control (ECDC) to define a methodology for evaluating and grading evidence and strength of recommendations in the field of public health, with emphasis on infectious disease epidemiology, prevention and control. One of the first steps was to review existing quality appraisal tools (QATs) for individual research studies of various designs relevant to this area, using a question-based approach. Through team discussions and expert consultations, we identified 20 relevant types of public health questions, which were grouped into six domains, i.e. characteristics of the pathogen, burden of disease, diagnosis, risk factors, intervention, and implementation of intervention. Previously published systematic reviews were used and supplemented by expert consultation to identify suitable QATs. Finally, a matrix was constructed for matching questions to study designs suitable to address them and respective QATs. Key features of each of the included QATs were then analyzed, in particular in respect to its intended use, types of questions and answers, presence/absence of a quality score, and if a validation was performed. In total we identified 21 QATs and 26 study designs, and matched them. Four QATs were suitable for experimental quantitative study designs, eleven for observational quantitative studies, two for qualitative studies, three for economic studies, one for diagnostic test accuracy studies, and one for animal studies. Included QATs consisted of six to 28 items. Six of the QATs had a summary quality score. Fourteen QATs had undergone at least one validation procedure. The results of this methodological study can be used as an inventory of potentially relevant questions, appropriate study designs and QATs for researchers and authorities engaged with evidence-based decision-making in infectious disease epidemiology, prevention and control.

Pilot study of extremely low frequency magnetic fields emitted by transformers in dwellings. Social aspects.

PubMed

Zaryabova, Victoria; Shalamanova, Tsvetelina; Israel, Michel

2013-06-01

A large number of epidemiologic studies examining the potential effect of residential exposure to extremely-low frequency (ELF) magnetic fields and childhood leukemia have been published. Two pooled analyses [Ahlbom A, Day N, Feychting M, Roman E, Skinner J, Dockerty J, Linet M, et al. (2000). A pooled analysis of magnetic fields and childhood leukaemia. Br J Cancer. 83(5):692-698; Greenland S, Sheppard AR, Kaune WT, Poole C, Kelsh AM (2000). A pooled analysis of magnetic fields, wire codes, and childhood leukemia. Epidemiology. 11(6):624-634], which included the major epidemiologic studies on ELF magnetic fields and childhood leukemia showed twofold increase in childhood leukemia risk in association with residential ELF exposure above 0.3-0.4 μT. Based on "limited" epidemiologic evidence linking ELF exposure to childhood leukemia and "inadequate evidence" for carcinogenicity of ELF in rodent bioassays, the International Agency for Research on Cancer (IARC) classified ELF magnetic fields as a possible human carcinogen (2B classification) [International Agency for Research on Cancer (IARC) (2002). Non-ionizing radiation, Part 1: Static and extremely low-frequency (ELF) electric and magnetic fields. IARC monographs on the evaluation of carcinogenic risks to humans. Vol. 80. IARC Press: Lyon], confirmed by WHO on the basis of studies published after 2000 [World Health Organization. Extremely low frequency fields. In: 238 Environmental health criteria, Geneva: WHO; 2007]. The analysis of more recent studies of ELF magnetic fields and childhood leukemia had small findings and propose methodological improvements concerning the uncertainties in epidemiological approaches and exposure assessment, bias in selection of controls [Kheifets L, Oksuzyan S (2008). Exposure assessment and other challenges in non-ionizing radiation studies of childhood leukaemia. Radiat Prot Dosimetry. 132(2):139-147]. By the end of 2010, 37 countries had been identified for possible participation in the International study TRANSEXPO. The pilot work has been completed in five countries (Finland, Hungary, Israel, Switzerland and Bulgaria). In 2008, Bulgaria through the National Centre of Public Health Protection joined with pilot study in TRANSEXPO Project. At this first stage of the project our investigation was directed to performing measurements in dwellings with built-in transformer stations, collecting data of population and cancer registry and choosing the epidemiology design feasible for continuing the project. Taking into account the available sources of information in Bulgaria (different registers of the population) needed for epidemiological approach, it was found that the most appropriate epidemiology design would be the nested case-control study. Control group could be collected in accordance with the international requirements for such epidemiological studies. This approach could be modified in the course of the further study in order to ensure achievement of the purposes of the main international requirements of the study.

Epidemiological evidence of carcinogenicity of chlorinated organics in drinking water.

PubMed

Cantor, K P

1982-12-01

Concern has recently been voiced over possible chronic toxicity associated with chlorination of public drinking water supplies in the United States. This paper reviews the available evidence and the studies underway to further evaluate hypothesized associations between cancer risk and byproducts of chlorination. Preliminary data from measures of halogenated volatiles and personal exposure histories from respondents in a large epidemiologic study of bladder cancer are presented. These data support the use in epidemiologic studies of categorical measures of exposure and suggest that results from completed case-control studies, based on death certificates, may have underestimated the true risk of exposure to chlorination by-products. The current generation of studies which use a case-control interview design offer many advantages over earlier efforts to evaluate this issue.

Epidemiological evidence of carcinogenicity of chlorinated organics in drinking water.

PubMed Central

Cantor, K P

1982-01-01

Concern has recently been voiced over possible chronic toxicity associated with chlorination of public drinking water supplies in the United States. This paper reviews the available evidence and the studies underway to further evaluate hypothesized associations between cancer risk and byproducts of chlorination. Preliminary data from measures of halogenated volatiles and personal exposure histories from respondents in a large epidemiologic study of bladder cancer are presented. These data support the use in epidemiologic studies of categorical measures of exposure and suggest that results from completed case-control studies, based on death certificates, may have underestimated the true risk of exposure to chlorination by-products. The current generation of studies which use a case-control interview design offer many advantages over earlier efforts to evaluate this issue. PMID:6759108

ALTERNATIVE EXPOSURE MEASUREMENT DESIGNS TO IMPROVE EPIDEMIOLOGICAL STUDY DESIGNS: USE OF HUMAN EXPOSURE STUDY DATA TO IDENTIFY EXPOSURE QUESTIONS FOR USE IN THE NCS

EPA Science Inventory

The National Human Exposure Assessment Survey in Maryland (NHEXAS-MD) was a longitudinal study of multimedia exposure to metals, pesticides, and polycyclic aromatic compounds (PAHs). Measurements were made and questionnaires were concurrently administered to identify sources o...

Sampling designs for HIV molecular epidemiology with application to Honduras.

PubMed

Shepherd, Bryan E; Rossini, Anthony J; Soto, Ramon Jeremias; De Rivera, Ivette Lorenzana; Mullins, James I

2005-11-01

Proper sampling is essential to characterize the molecular epidemiology of human immunodeficiency virus (HIV). HIV sampling frames are difficult to identify, so most studies use convenience samples. We discuss statistically valid and feasible sampling techniques that overcome some of the potential for bias due to convenience sampling and ensure better representation of the study population. We employ a sampling design called stratified cluster sampling. This first divides the population into geographical and/or social strata. Within each stratum, a population of clusters is chosen from groups, locations, or facilities where HIV-positive individuals might be found. Some clusters are randomly selected within strata and individuals are randomly selected within clusters. Variation and cost help determine the number of clusters and the number of individuals within clusters that are to be sampled. We illustrate the approach through a study designed to survey the heterogeneity of subtype B strains in Honduras.

The Epidemiology of Delirium: Challenges and Opportunities for Population Studies

PubMed Central

Davis, Daniel H.J.; Kreisel, Stefan H.; Muniz Terrera, Graciela; Hall, Andrew J.; Morandi, Alessandro; Boustani, Malaz; Neufeld, Karin J.; Lee, Hochang Benjamin; MacLullich, Alasdair M.J.; Brayne, Carol

2013-01-01

Delirium is a serious and common acute neuropsychiatric syndrome that is associated with short- and long-term adverse health outcomes. However, relatively little delirium research has been conducted in unselected populations. Epidemiologic research in such populations has the potential to resolve several questions of clinical significance in delirium. Part 1 of this article explores the importance of population selection, case-ascertainment, attrition, and confounding. Part 2 examines a specific question in delirium epidemiology: What is the relationship between delirium and trajectories of cognitive decline? This section assesses previous work through two systematic reviews and proposes a design for investigating delirium in the context of longitudinal cohort studies. Such a design requires robust links between community and hospital settings. Practical considerations for case-ascertainment in the hospital, as well as the necessary quality control of these programs, are outlined. We argue that attention to these factors is important if delirium research is to benefit fully from a population perspective. PMID:23907068

ALTERNATIVE EXPOSURE MEASUREMENT DESIGNS TO IMPROVE EPIDEMIOLOGICAL STUDY DESIGNS: DETERMINANTS OF TEMPORAL VARIABILITY IN ENVIRONMENTAL CONCENTRATIONS, EXPOSURES, AND BIOMARKERS

EPA Science Inventory

The National Human Exposure Assessment Survey in Maryland (NHEXAS-MD) was a longitudinal study of multimedia exposure to metals, pesticides, and polycyclic aromatic compounds (PAHs). Measurements were made and questionnaires were concurrently administered to identify sources o...

Design and implementation of observational studies to measure disease burden with a focus on stroke.

PubMed

Howard, George; Howard, Virginia J

2018-02-01

Observational epidemiological studies have the dual goals of measuring disease burden and assessing the association between exposures and outcomes. This report focuses on the first of these goals and provides an overview of design considerations of commonly used approaches, specifically community surveillance studies, cross-sectional studies, and longitudinal cohort studies. Each of these designs has strengths and weaknesses, with no study design being superior in all cases. Rather, these designs are complementary to achieve a better understanding of the burden of stroke.

Estimating the Occurrence of Child Maltreatment and Risk-Factor Effects: Benefits of a Mixed-Design Strategy in Epidemiologic Research.

ERIC Educational Resources Information Center

Bertolli, Jeanne; And Others

1995-01-01

This article discusses methodologic limitations of four observational study designs (ecologic, case-control, cross-sectional, and cohort) that dominate the child abuse and neglect literature and identifies key features of an "ideal" study of child maltreatment. It proposes a new mixed-design strategy, which improves ability to identify child…

Molecular epidemiology of tuberculosis: achievements and challenges to current knowledge.

PubMed Central

Murray, Megan; Nardell, Edward

2002-01-01

Over the past 10 years, molecular methods have become available with which to strain-type Mycobacterium tuberculosis. They have allowed researchers to study certain important but previously unresolved issues in the epidemiology of tuberculosis (TB). For example, some unsuspected microepidemics have been revealed and it has been shown that the relative contribution of recently acquired disease to the TB burden in many settings is far greater than had been thought. These findings have led to the strengthening of TB control. Other research has demonstrated the existence and described the frequency of exogenous reinfection in areas of high incidence. Much recent work has focused on the phenotypic variation among strains and has evaluated the relative transmissibility, virulence, and immunogenicity of different lineages of the organism. We summarize the recent achievements in TB epidemiology associated with the introduction of DNA fingerprinting techniques, and consider the implications of this technology for the design and analysis of epidemiological studies. PMID:12132006

Community Engagement in Epidemiological Research

PubMed Central

Sapienza, Jessica N.; Corbie-Smith, Giselle; Keim, Sarah; Fleischman, Alan R.

2007-01-01

Objectives Engaging communities has become a critical aspect of planning and implementing health research. The role community engagement should play in epidemiological and observational research remains unclear since much of this research is not directly generated by community concerns and is not interventional in nature. The National Children's Study (NCS), an observational longitudinal study of 100,000 children and their families, provides a model to help guide the development of community engagement strategies in epidemiologic research. Methodology This manuscript describes community engagement activities of the NCS during the planning phases of the study. Results There are many challenges of community engagement in epidemiologic research particularly before the actual research sites are determined. After communities of interest are designated many further issues must be resolved, including: defining the specific community, determining which residents or institutions represent the identified community, and developing trust and rapport through respectful engagement. Conclusions Community engagement is critical to the long-term success of any longitudinal epidemiologic study. A partnership with the community should be formed to ensure mutual respect and the establishment of an enduring relationship. Genuine community engagement offers the hope of enhancing recruitment, retention, and participant satisfaction. PMID:17512886

The emergence of translational epidemiology: from scientific discovery to population health impact.

PubMed

Khoury, Muin J; Gwinn, Marta; Ioannidis, John P A

2010-09-01

Recent emphasis on translational research (TR) is highlighting the role of epidemiology in translating scientific discoveries into population health impact. The authors present applications of epidemiology in TR through 4 phases designated T1-T4, illustrated by examples from human genomics. In T1, epidemiology explores the role of a basic scientific discovery (e.g., a disease risk factor or biomarker) in developing a "candidate application" for use in practice (e.g., a test used to guide interventions). In T2, epidemiology can help to evaluate the efficacy of a candidate application by using observational studies and randomized controlled trials. In T3, epidemiology can help to assess facilitators and barriers for uptake and implementation of candidate applications in practice. In T4, epidemiology can help to assess the impact of using candidate applications on population health outcomes. Epidemiology also has a leading role in knowledge synthesis, especially using quantitative methods (e.g., meta-analysis). To explore the emergence of TR in epidemiology, the authors compared articles published in selected issues of the Journal in 1999 and 2009. The proportion of articles identified as translational doubled from 16% (11/69) in 1999 to 33% (22/66) in 2009 (P = 0.02). Epidemiology is increasingly recognized as an important component of TR. By quantifying and integrating knowledge across disciplines, epidemiology provides crucial methods and tools for TR.

The Emergence of Translational Epidemiology: From Scientific Discovery to Population Health Impact

PubMed Central

Khoury, Muin J.; Gwinn, Marta; Ioannidis, John P. A.

2010-01-01

Recent emphasis on translational research (TR) is highlighting the role of epidemiology in translating scientific discoveries into population health impact. The authors present applications of epidemiology in TR through 4 phases designated T1–T4, illustrated by examples from human genomics. In T1, epidemiology explores the role of a basic scientific discovery (e.g., a disease risk factor or biomarker) in developing a “candidate application” for use in practice (e.g., a test used to guide interventions). In T2, epidemiology can help to evaluate the efficacy of a candidate application by using observational studies and randomized controlled trials. In T3, epidemiology can help to assess facilitators and barriers for uptake and implementation of candidate applications in practice. In T4, epidemiology can help to assess the impact of using candidate applications on population health outcomes. Epidemiology also has a leading role in knowledge synthesis, especially using quantitative methods (e.g., meta-analysis). To explore the emergence of TR in epidemiology, the authors compared articles published in selected issues of the Journal in 1999 and 2009. The proportion of articles identified as translational doubled from 16% (11/69) in 1999 to 33% (22/66) in 2009 (P = 0.02). Epidemiology is increasingly recognized as an important component of TR. By quantifying and integrating knowledge across disciplines, epidemiology provides crucial methods and tools for TR. PMID:20688899

Epidemiological study air disaster in Amsterdam (ESADA): study design.

PubMed

Slottje, Pauline; Huizink, Anja C; Twisk, Jos W R; Witteveen, Anke B; van der Ploeg, Henk M; Bramsen, Inge; Smidt, Nynke; Bijlsma, Joost A; Bouter, Lex M; van Mechelen, Willem; Smid, Tjabe

2005-05-30

In 1992, a cargo aircraft crashed into apartment buildings in Amsterdam, killing 43 victims and destroying 266 apartments. In the aftermath there were speculations about the cause of the crash, potential exposures to hazardous materials due to the disaster and the health consequences. Starting in 2000, the Epidemiological Study Air Disaster in Amsterdam (ESADA) aimed to assess the long-term health effects of occupational exposure to this disaster on professional assistance workers. Epidemiological study among all the exposed professional fire-fighters and police officers who performed disaster-related task(s), and hangar workers who sorted the wreckage of the aircraft, as well as reference groups of their non-exposed colleagues who did not perform any disaster-related tasks. The study took place, on average, 8.5 years after the disaster. Questionnaires were used to assess details on occupational exposure to the disaster. Health measures comprised laboratory assessments in urine, blood and saliva, as well as self-reported current health measures, including health-related quality of life, and various physical and psychological symptoms. In this paper we describe and discuss the design of the ESADA. The ESADA will provide additional scientific knowledge on the long-term health effects of technological disasters on professional workers.

Heavy Metal Exposure and Metabolic Syndrome: Evidence from Human and Model System Studies.

PubMed

Planchart, Antonio; Green, Adrian; Hoyo, Cathrine; Mattingly, Carolyn J

2018-03-01

Metabolic syndrome (MS) describes the co-occurrence of conditions that increase one's risk for heart disease and other disorders such as diabetes and stroke. The worldwide increase in the prevalence of MS cannot be fully explained by lifestyle factors such as sedentary behavior and caloric intake alone. Environmental exposures, such as heavy metals, have been implicated, but results are conflicting and possible mechanisms remain unclear. To assess recent progress in determining a possible role between heavy metal exposure and MS, we reviewed epidemiological and model system data for cadmium (Cd), lead (Pb), and mercury (Hg) from the last decade. Data from 36 epidemiological studies involving 17 unique countries/regions and 13 studies leveraging model systems are included in this review. Epidemiological and model system studies support a possible association between heavy metal exposure and MS or comorbid conditions; however, results remain conflicting. Epidemiological studies were predominantly cross-sectional and collectively, they highlight a global interest in this question and reveal evidence of differential susceptibility by sex and age to heavy metal exposures. In vivo studies in rats and mice and in vitro cell-based assays provide insights into potential mechanisms of action relevant to MS including altered regulation of lipid and glucose homeostasis, adipogenesis, and oxidative stress. Heavy metal exposure may contribute to MS or comorbid conditions; however, available data are conflicting. Causal inference remains challenging as epidemiological data are largely cross-sectional; and variation in study design, including samples used for heavy metal measurements, age of subjects at which MS outcomes are measured; the scope and treatment of confounding factors; and the population demographics vary widely. Prospective studies, standardization or increased consistency across study designs and reporting, and consideration of molecular mechanisms informed by model system studies are needed to better assess potential causal links between heavy metal exposure and MS.

Regression Discontinuity Designs in Epidemiology

PubMed Central

Moscoe, Ellen; Mutevedzi, Portia; Newell, Marie-Louise; Bärnighausen, Till

2014-01-01

When patients receive an intervention based on whether they score below or above some threshold value on a continuously measured random variable, the intervention will be randomly assigned for patients close to the threshold. The regression discontinuity design exploits this fact to estimate causal treatment effects. In spite of its recent proliferation in economics, the regression discontinuity design has not been widely adopted in epidemiology. We describe regression discontinuity, its implementation, and the assumptions required for causal inference. We show that regression discontinuity is generalizable to the survival and nonlinear models that are mainstays of epidemiologic analysis. We then present an application of regression discontinuity to the much-debated epidemiologic question of when to start HIV patients on antiretroviral therapy. Using data from a large South African cohort (2007–2011), we estimate the causal effect of early versus deferred treatment eligibility on mortality. Patients whose first CD4 count was just below the 200 cells/μL CD4 count threshold had a 35% lower hazard of death (hazard ratio = 0.65 [95% confidence interval = 0.45–0.94]) than patients presenting with CD4 counts just above the threshold. We close by discussing the strengths and limitations of regression discontinuity designs for epidemiology. PMID:25061922

Melanocortin-1 receptor, skin cancer and phenotypic characteristics (M-SKIP) project: study design and methods for pooling results of genetic epidemiological studies

PubMed Central

2012-01-01

Background For complex diseases like cancer, pooled-analysis of individual data represents a powerful tool to investigate the joint contribution of genetic, phenotypic and environmental factors to the development of a disease. Pooled-analysis of epidemiological studies has many advantages over meta-analysis, and preliminary results may be obtained faster and with lower costs than with prospective consortia. Design and methods Based on our experience with the study design of the Melanocortin-1 receptor (MC1R) gene, SKin cancer and Phenotypic characteristics (M-SKIP) project, we describe the most important steps in planning and conducting a pooled-analysis of genetic epidemiological studies. We then present the statistical analysis plan that we are going to apply, giving particular attention to methods of analysis recently proposed to account for between-study heterogeneity and to explore the joint contribution of genetic, phenotypic and environmental factors in the development of a disease. Within the M-SKIP project, data on 10,959 skin cancer cases and 14,785 controls from 31 international investigators were checked for quality and recoded for standardization. We first proposed to fit the aggregated data with random-effects logistic regression models. However, for the M-SKIP project, a two-stage analysis will be preferred to overcome the problem regarding the availability of different study covariates. The joint contribution of MC1R variants and phenotypic characteristics to skin cancer development will be studied via logic regression modeling. Discussion Methodological guidelines to correctly design and conduct pooled-analyses are needed to facilitate application of such methods, thus providing a better summary of the actual findings on specific fields. PMID:22862891

Helicobacter pylori and Cancer

MedlinePlus

... alpha-tocopherol, beta-carotene lung cancer prevention study: Design, methods, participant characteristics, and compliance. The ATBC Cancer Prevention Study Group. Annals of Epidemiology 1994; 4(1):1–10. [PubMed Abstract] Kamangar F, Dawsey ...

Human exposure to chemical mixtures: Challenges for the integration of toxicology with epidemiology data in risk assessment.

PubMed

Hernández, Antonio F; Tsatsakis, Aristidis M

2017-05-01

Little is known about the potential adverse effects from longterm exposure to complex mixtures at low doses, close to health-based reference values. Traditional chemical-specific risk assessment based on animal testing may be insufficient and the lack of toxicological studies on chemical mixtures remains a major regulatory challenge. Hence, new methodologies on cumulative risk assessment are being developed but still present major limitations. Evaluation of chemical mixture effects requires an integrated and systematic approach and close collaboration across different scientific fields, particularly toxicology, epidemiology, exposure science, risk assessment and statistics for a proper integration of data from all these disciplines. Well designed and conducted epidemiological studies can take advantage of this new paradigm and can provide insight to support the correlation between humans low-dose exposures and diseases, thus avoiding the uncertainty associated with extrapolation across species. In this regard, human epidemiology studies may play a significant role in the new vision of toxicity testing. However, this type of information has not been fully considered in risk assessment, mainly due to the inherent limitations of epidemiologic studies. An integrated approach of in vivo, in vitro and in silico data, together with systematic reviews or meta-analysis of high quality epidemiological studies will improve the robustness of risk assessment of chemical mixtures and will provide a stronger basis for regulatory decisions. The ultimate goal is that experimental and mechanistic data can lend support and biological plausibility to the human epidemiological observations. Copyright © 2017 Elsevier Ltd. All rights reserved.

Methods and Technologies Branch (MTB)

Cancer.gov

The Methods and Technologies Branch focuses on methods to address epidemiologic data collection, study design and analysis, and to modify technological approaches to better understand cancer susceptibility.

The big data potential of epidemiological studies for criminology and forensics.

PubMed

DeLisi, Matt

2018-07-01

Big data, the analysis of original datasets with large samples ranging from ∼30,000 to one million participants to mine unexplored data, has been under-utilized in criminology. However, there have been recent calls for greater synthesis between epidemiology and criminology and a small number of scholars have utilized epidemiological studies that were designed to measure alcohol and substance use to harvest behavioral and psychiatric measures that relate to the study of crime. These studies have been helpful in producing knowledge about the most serious, violent, and chronic offenders, but applications to more pathological forensic populations is lagging. Unfortunately, big data relating to crime and justice are restricted and limited to criminal justice purposes and not easily available to the research community. Thus, the study of criminal and forensic populations is limited in terms of data volume, velocity, and variety. Additional forays into epidemiology, increased use of available online judicial and correctional data, and unknown new frontiers are needed to bring criminology up to speed in the big data arena. Copyright © 2016 Elsevier Ltd and Faculty of Forensic and Legal Medicine. All rights reserved.

International Lymphoma Epidemiology Consortium (InterLymph)

Cancer.gov

A consortium designed to enhance collaboration among epidemiologists studying lymphoma, to provide a forum for the exchange of research ideas, and to create a framework for collaborating on analyses that pool data from multiple studies

[Epidemiology of urolithiasis in Spain: Review of published demographic data in the period 1977-2016.

PubMed

Sánchez-Martín, Francisco María; Angerri, Oriol; Emiliani, Esteban; Moncada, Enver; Carpio, José; Millán, Félix; Villavicencio, Humberto

2017-03-01

Epidemiological data on urolithiasis in Spain have appeared in publications especially local and regional level, with few referrals to Spanish national territory. The aim of this paper is to review and systematize the epidemiological data published on urolithiasis in Spain. We reviewed publications in national and international scientific journals, meetings and conferences, and research reports (1977-2016). PubMed search (indexed papers) and manual bibliography search (not indexed works) were performed. Bibliometric data evaluated: Year of publication, geographic area, number of cases, sample type, study design and publishing format. Demographic systematization of data: age, age and frequency distribution by gender, family history, social stratum, profession, place of residence, ethnics, seasonality and dietary habits. Publications revised: 79 corresponding to 56 main authors. Selected publications with original data: 42 (2 composed by Part I and II, and 2 composed by paper and thesis), corresponding to 35 authors. Bibliometric and demographic data of all publications are displayed in tables, sorted by variables. The comprehensive review of studies on epidemiology in Spain constitutes a solid basis for future research about epidemiology of urolithiasis.

[Occupational epidemiology: some methodological considerations].

PubMed

Alvear-Galindo, María Guadalupe; del Pilar Paz-Román, María

2006-01-01

During the last decade, occupational epidemiology has gained a great importance, not only because of the increase of pollutants and their noxiousness, but also because it has gone from the descriptive to the analytic level. The purpose of this work is to present what has been reported on epidemiological studies, different ways of characterizing and measuring occupational exposure, by emphasizing slants of exposure and selection measurement. In the reviewed studies, an interest in improving the exposure evaluation has been shown. The mainly reported measurement slants are the ways of measuring and classifying the exposure. The main designs were transversal with the use of matrixes to improve the evaluation of exposure. Conditions of hygiene and security were considered in order to control the quality of the information. This information was analyzed with different criteria. Some of the elements that hinder the research on occupational epidemiology are a mixed exposure, small populations, lack of exposure data, low levels of exposure and long periods of illness latency. Some breakthroughs in the strategies of epidemiological analysis and some other areas of knowledge have made possible a better understanding of work and health conditions of workers.

Soy intake is associated with lower lung cancer risk: results from a meta-analysis of epidemiologic studies123

PubMed Central

Yang, Wan-Shui; Va, Puthiery; Wong, Man-Yu; Zhang, Huan-Ling

2011-01-01

Background: Although several in vitro and animal in vivo studies have suggested that soy or soy isoflavones may exert inhibitory effects on lung carcinogenesis, epidemiologic studies have reported inconclusive results on the association between soy intake and lung cancer. Objective: The aim of this meta-analysis was to investigate whether an association exists between soy and lung cancer in epidemiologic studies. Design: We searched PubMed, EMBASE, and the Cochrane Library from their inception to February 2011 for both case-control and cohort studies that assessed soy consumption and lung cancer risk. Study-specific risk estimates were combined by using fixed-effect or random-effect models. Results: A total of 11 epidemiologic studies that consisted of 8 case-control and 3 prospective cohort studies were included. A significantly inverse association was shown between soy intake and lung cancer with an overall RR of 0.77 (95% CI: 0.65, 0.92). Findings were slightly different when analyses were restricted to 5 high-quality studies (RR: 0.70; 95% CI: 0.45, 0.99). In a subgroup meta-analysis, a statistically significant protective effect of soy consumption was observed in women (RR: 0.79; 95% CI: 0.67, 0.93), never smokers (RR: 0.62; 95% CI: 0.51, 0.76), and Asian populations (RR: 0.86; 95% CI: 0.74, 0.98). Conclusions: Our findings indicate that the consumption of soy food is associated with lower lung cancer risk. Because of different methods used to assess soy consumption across studies, more well-designed cohort studies or intervention studies that use unified measures of soy intake are needed to fully characterize such an association. PMID:22071712

The epidemiology and surveillance workforce among local health departments in California: mutual aid and surge capacity for routine and emergency infectious disease situations.

PubMed

Enanoria, Wayne T A; Crawley, Adam W; Hunter, Jennifer C; Balido, Jeannie; Aragon, Tomas J

2014-01-01

Public health surveillance and epidemiologic investigations are critical public health functions for identifying threats to the health of a community. We conducted a survey of local health departments (LHDs) in California to describe the workforce that supports public health surveillance and epidemiologic functions during routine and emergency infectious disease situations. The target population consisted of the 61 LHDs in California. The online survey instrument was designed to collect information about the workforce involved in key epidemiologic functions. We also examined how the public health workforce increases its epidemiologic capacity during infectious disease emergencies. Of 61 LHDs in California, 31 (51%) completed the survey. A wide range of job classifications contribute to epidemiologic functions routinely, and LHDs rely on both internal and external sources of epidemiologic surge capacity during infectious disease emergencies. This study found that while 17 (55%) LHDs reported having a mutual aid agreement with at least one other organization for emergency response, only nine (29%) LHDs have a mutual aid agreement specifically for epidemiology and surveillance functions. LHDs rely on a diverse workforce to conduct epidemiology and public health surveillance functions, emphasizing the need to identify and describe the types of staff positions that could benefit from public health surveillance and epidemiology training. While some organizations collaborate with external partners to support these functions during an emergency, many LHDs do not rely on mutual aid agreements for epidemiology and surveillance activities.

Mental health epidemiological research in South America: recent findings

PubMed Central

Silva de Lima, Maurício; Garcia de Oliveira Soares, Bernardo; de Jesus Mari, Jair

2004-01-01

This paper aims to review the recent mental health epidemiological research conducted in South America. The Latin American and the Caribbean (LILACS) database was searched from 1999 to 2003 using a specific strategy for identification of cohort, case-control and cross-sectional population-based studies in South America. The authors screened references and identified relevant studies. Further studies were obtained contacting local experts in epidemiology. 140 references were identified, and 12 studies were selected. Most selected studies explored the prevalence and risk factors for common mental disorders, and several of them used sophisticated methods of sample selection and analysis. There is a need for improving the quality of psychiatric journals in Latin America, and for increasing the distribution and access to research data. Regionally relevant problems such as violence and substance abuse should be considered in designing future investigations in this area. PMID:16633474

Towards non-conventional methods of designing register-based epidemiological studies: An application to pediatric research.

PubMed

Gong, Tong; Brew, Bronwyn; Sjölander, Arvid; Almqvist, Catarina

2017-07-01

Various epidemiological designs have been applied to investigate the causes and consequences of fetal growth restriction in register-based observational studies. This review seeks to provide an overview of several conventional designs, including cohort, case-control and more recently applied non-conventional designs such as family-based designs. We also discuss some practical points regarding the application and interpretation of family-based designs. Definitions of each design, the study population, the exposure and the outcome measures are briefly summarised. Examples of study designs are taken from the field of low birth-weight research for illustrative purposes. Also examined are relative advantages and disadvantages of each design in terms of assumptions, potential selection and information bias, confounding and generalisability. Kinship data linkage, statistical models and result interpretation are discussed specific to family-based designs. When all information is retrieved from registers, there is no evident preference of the case-control design over the cohort design to estimate odds ratios. All conventional designs included in the review are prone to bias, particularly due to residual confounding. Family-based designs are able to reduce such bias and strengthen causal inference. In the field of low birth-weight research, family-based designs have been able to confirm a negative association not confounded by genetic or shared environmental factors between low birth weight and the risk of asthma. We conclude that there is a broader need for family-based design in observational research as evidenced by the meaningful contributions to the understanding of the potential causal association between low birth weight and subsequent outcomes.

Epidemiologic study of residential proximity to transmission lines and childhood cancer in California: description of design, epidemiologic methods and study population

PubMed Central

Kheifets, Leeka; Crespi, Catherine M; Hooper, Chris; Oksuzyan, Sona; Cockburn, Myles; Ly, Thomas; Mezei, Gabor

2015-01-01

We conducted a large epidemiologic case-control study in California to examine the association between childhood cancer risk and distance from the home address at birth to the nearest high-voltage overhead transmission line as a replication of the study of Draper et al. in the United Kingdom. We present a detailed description of the study design, methods of case ascertainment, control selection, exposure assessment and data analysis plan. A total of 5788 childhood leukemia cases and 3308 childhood central nervous system cancer cases (included for comparison) and matched controls were available for analysis. Birth and diagnosis addresses of cases and birth addresses of controls were geocoded. Distance from the home to nearby overhead transmission lines was ascertained on the basis of the electric power companies’ geographic information system (GIS) databases, additional Google Earth aerial evaluation and site visits to selected residences. We evaluated distances to power lines up to 2000 m and included consideration of lower voltages (60–69 kV). Distance measures based on GIS and Google Earth evaluation showed close agreement (Pearson correlation >0.99). Our three-tiered approach to exposure assessment allowed us to achieve high specificity, which is crucial for studies of rare diseases with low exposure prevalence. PMID:24045429

Mechanistic and Technical Challenges in Studying the Human Microbiome and Cancer Epidemiology.

PubMed

Verma, Mukesh

2017-04-01

This article reviews the significance of the microbiome in cancer epidemiology, mechanistic and technical challenges in the field, and characterization of the microbiome in different tumor types to identify biomarkers of risk, progression, and prognosis. Publications on the microbiome and cancer epidemiology were reviewed to analyze sample collection and processing, microbiome taxa characterization by 16S ribosomal RNA sequencing, and microbiome metabolite characterization (metabotyping) by nuclear magnetic resonance and mass spectrometry. The analysis identified methodology types, research design, sample types, and issues in integrating data from different platforms. Aerodigestive cancer epidemiology studies conducted by different groups demonstrated the significance of microbiome information in developing approaches to improve health. Challenges exist in sample preparation and processing (eg, standardization of methods for collection and analysis). These challenges relate to technology, data integration from "omics" studies, inherent bias in primer selection during 16S ribosomal RNA sequencing, the need for large consortia with well-characterized biospecimens, cause and effect issues, resilience of microbiota to exposure events (requires longitudinal studies), and expanding studies for fungal and viral diversity (most studies used bacterial 16S ribosomal RNA sequencing for microbiota characterization). Despite these challenges, microbiome and cancer epidemiology studies are significant and may facilitate cancer risk assessment, diagnosis, and prognosis. In the future, clinical trials likely will use microbiota modifications to improve the efficacy of existing treatments.

Mechanistic and Technical Challenges in Studying the Human Microbiome and Cancer Epidemiology

PubMed Central

2016-01-01

This article reviews the significance of the microbiome in cancer epidemiology, mechanistic and technical challenges in the field, and characterization of the microbiome in different tumor types to identify biomarkers of risk, progression, and prognosis. Publications on the microbiome and cancer epidemiology were reviewed to analyze sample collection and processing, microbiome taxa characterization by 16S ribosomal RNA sequencing, and microbiome metabolite characterization (metabotyping) by nuclear magnetic resonance and mass spectrometry. The analysis identified methodology types, research design, sample types, and issues in integrating data from different platforms. Aerodigestive cancer epidemiology studies conducted by different groups demonstrated the significance of microbiome information in developing approaches to improve health. Challenges exist in sample preparation and processing (eg, standardization of methods for collection and analysis). These challenges relate to technology, data integration from “omics” studies, inherent bias in primer selection during 16S ribosomal RNA sequencing, the need for large consortia with well-characterized biospecimens, cause and effect issues, resilience of microbiota to exposure events (requires longitudinal studies), and expanding studies for fungal and viral diversity (most studies used bacterial 16S ribosomal RNA sequencing for microbiota characterization). Despite these challenges, microbiome and cancer epidemiology studies are significant and may facilitate cancer risk assessment, diagnosis, and prognosis. In the future, clinical trials likely will use microbiota modifications to improve the efficacy of existing treatments. PMID:27121074

The science of epidemiology and the methods needed for public health assessments: a review of epidemiology textbooks

PubMed Central

2014-01-01

Objectives Epidemiology is often described as ‘the science of public health’. Here we aim to assess the extent that epidemiological methods, as covered in contemporary standard textbooks, provide tools that can assess the relative magnitude of public health problems and can be used to help rank and assess public health priorities. Study Design Narrative literature review. Methods Thirty textbooks were grouped into three categories; pure, extended or applied epidemiology, were reviewed with attention to the ways the discipline is characterised and the nature of the analytical methods described. Results Pure texts tend to present a strict hierarchy of methods with those metrics deemed to best serve aetiological inquiry at the top. Extended and applied texts employ broader definitions of epidemiology but in most cases, the metrics described are also those used in aetiological inquiry and may not be optimal for capturing the consequences and social importance of injuries and disease onsets. Conclusions The primary scientific purpose of epidemiology, even amongst ‘applied’ textbooks, is aetiological inquiry. Authors do not readily extend to methods suitable for assessing public health problems and priorities. PMID:24507570

Alzheimer’s Disease and Environmental Exposure to Lead: The Epidemiologic Evidence and Potential Role of Epigenetics

PubMed Central

Bakulski, Kelly M.; Rozek, Laura S.; Dolinoy, Dana C.; Paulson, Henry L.; Hu, Howard

2013-01-01

Several lines of evidence indicate that the etiology of late-onset Alzheimer’s disease (LOAD) is complex, with significant contributions from both genes and environmental factors. Recent research suggests the importance of epigenetic mechanisms in defining the relationship between environmental exposures and LOAD. In epidemiologic studies of adults, cumulative lifetime lead (Pb) exposure has been associated with accelerated declines in cognition. In addition, research in animal models suggests a causal association between Pb exposure during early life, epigenetics, and LOAD. There are multiple challenges to human epidemiologic research evaluating the relationship between epigenetics, LOAD, and Pb exposure. Epidemiologic studies are not well-suited to accommodate the long latency period between exposures during early life and onset of Alzheimer’s disease. There is also a lack of validated circulating epigenetics biomarkers and retrospective biomarkers of Pb exposure. Members of our research group have shown bone Pb is an accurate measurement of historical Pb exposure in adults, offering an avenue for future epidemiologic studies. However, this would not address the risk of LOAD attributable to early-life Pb exposures. Future studies that use a cohort design to measure both Pb exposure and validated epigenetic biomarkers of LOAD will be useful to clarify this important relationship. PMID:22272628

Concerted Uranium Research in Europe (CURE): toward a collaborative project integrating dosimetry, epidemiology and radiobiology to study the effects of occupational uranium exposure.

PubMed

Laurent, Olivier; Gomolka, Maria; Haylock, Richard; Blanchardon, Eric; Giussani, Augusto; Atkinson, Will; Baatout, Sarah; Bingham, Derek; Cardis, Elisabeth; Hall, Janet; Tomasek, Ladislav; Ancelet, Sophie; Badie, Christophe; Bethel, Gary; Bertho, Jean-Marc; Bouet, Ségolène; Bull, Richard; Challeton-de Vathaire, Cécile; Cockerill, Rupert; Davesne, Estelle; Ebrahimian, Teni; Engels, Hilde; Gillies, Michael; Grellier, James; Grison, Stephane; Gueguen, Yann; Hornhardt, Sabine; Ibanez, Chrystelle; Kabacik, Sylwia; Kotik, Lukas; Kreuzer, Michaela; Lebacq, Anne Laure; Marsh, James; Nosske, Dietmar; O'Hagan, Jackie; Pernot, Eileen; Puncher, Matthew; Rage, Estelle; Riddell, Tony; Roy, Laurence; Samson, Eric; Souidi, Maamar; Turner, Michelle C; Zhivin, Sergey; Laurier, Dominique

2016-06-01

The potential health impacts of chronic exposures to uranium, as they occur in occupational settings, are not well characterized. Most epidemiological studies have been limited by small sample sizes, and a lack of harmonization of methods used to quantify radiation doses resulting from uranium exposure. Experimental studies have shown that uranium has biological effects, but their implications for human health are not clear. New studies that would combine the strengths of large, well-designed epidemiological datasets with those of state-of-the-art biological methods would help improve the characterization of the biological and health effects of occupational uranium exposure. The aim of the European Commission concerted action CURE (Concerted Uranium Research in Europe) was to develop protocols for such a future collaborative research project, in which dosimetry, epidemiology and biology would be integrated to better characterize the effects of occupational uranium exposure. These protocols were developed from existing European cohorts of workers exposed to uranium together with expertise in epidemiology, biology and dosimetry of CURE partner institutions. The preparatory work of CURE should allow a large scale collaborative project to be launched, in order to better characterize the effects of uranium exposure and more generally of alpha particles and low doses of ionizing radiation.

Automated Dental Epidemiology System. II. Systems Analysis and Functional Design,

DTIC Science & Technology

1983-08-01

reduction of time and expense required for dental treatment and a minimization of patient time lost from military duties. Navy dentistry can thus be...regard, dental epidemiology can be especially valuable for evaluating and improving the Navy preventive dentistry program. It has been recommended that...processing applications to dentistry and dental epidemiology was performed. Alternative means to improve military dental epidemiology techniques and

Design Characteristics Influence Performance of Clinical Prediction Rules in Validation: A Meta-Epidemiological Study

PubMed Central

Ban, Jong-Wook; Emparanza, José Ignacio; Urreta, Iratxe; Burls, Amanda

2016-01-01

Background Many new clinical prediction rules are derived and validated. But the design and reporting quality of clinical prediction research has been less than optimal. We aimed to assess whether design characteristics of validation studies were associated with the overestimation of clinical prediction rules’ performance. We also aimed to evaluate whether validation studies clearly reported important methodological characteristics. Methods Electronic databases were searched for systematic reviews of clinical prediction rule studies published between 2006 and 2010. Data were extracted from the eligible validation studies included in the systematic reviews. A meta-analytic meta-epidemiological approach was used to assess the influence of design characteristics on predictive performance. From each validation study, it was assessed whether 7 design and 7 reporting characteristics were properly described. Results A total of 287 validation studies of clinical prediction rule were collected from 15 systematic reviews (31 meta-analyses). Validation studies using case-control design produced a summary diagnostic odds ratio (DOR) 2.2 times (95% CI: 1.2–4.3) larger than validation studies using cohort design and unclear design. When differential verification was used, the summary DOR was overestimated by twofold (95% CI: 1.2 -3.1) compared to complete, partial and unclear verification. The summary RDOR of validation studies with inadequate sample size was 1.9 (95% CI: 1.2 -3.1) compared to studies with adequate sample size. Study site, reliability, and clinical prediction rule was adequately described in 10.1%, 9.4%, and 7.0% of validation studies respectively. Conclusion Validation studies with design shortcomings may overestimate the performance of clinical prediction rules. The quality of reporting among studies validating clinical prediction rules needs to be improved. PMID:26730980

Design Characteristics Influence Performance of Clinical Prediction Rules in Validation: A Meta-Epidemiological Study.

PubMed

Ban, Jong-Wook; Emparanza, José Ignacio; Urreta, Iratxe; Burls, Amanda

2016-01-01

Many new clinical prediction rules are derived and validated. But the design and reporting quality of clinical prediction research has been less than optimal. We aimed to assess whether design characteristics of validation studies were associated with the overestimation of clinical prediction rules' performance. We also aimed to evaluate whether validation studies clearly reported important methodological characteristics. Electronic databases were searched for systematic reviews of clinical prediction rule studies published between 2006 and 2010. Data were extracted from the eligible validation studies included in the systematic reviews. A meta-analytic meta-epidemiological approach was used to assess the influence of design characteristics on predictive performance. From each validation study, it was assessed whether 7 design and 7 reporting characteristics were properly described. A total of 287 validation studies of clinical prediction rule were collected from 15 systematic reviews (31 meta-analyses). Validation studies using case-control design produced a summary diagnostic odds ratio (DOR) 2.2 times (95% CI: 1.2-4.3) larger than validation studies using cohort design and unclear design. When differential verification was used, the summary DOR was overestimated by twofold (95% CI: 1.2 -3.1) compared to complete, partial and unclear verification. The summary RDOR of validation studies with inadequate sample size was 1.9 (95% CI: 1.2 -3.1) compared to studies with adequate sample size. Study site, reliability, and clinical prediction rule was adequately described in 10.1%, 9.4%, and 7.0% of validation studies respectively. Validation studies with design shortcomings may overestimate the performance of clinical prediction rules. The quality of reporting among studies validating clinical prediction rules needs to be improved.

Directed acyclic graphs (DAGs): an aid to assess confounding in dental research.

PubMed

Merchant, Anwar T; Pitiphat, Waranuch

2002-12-01

Confounding, a special type of bias, occurs when an extraneous factor is associated with the exposure and independently affects the outcome. In order to get an unbiased estimate of the exposure-outcome relationship, we need to identify potential confounders, collect information on them, design appropriate studies, and adjust for confounding in data analysis. However, it is not always clear which variables to collect information on and adjust for in the analyses. Inappropriate adjustment for confounding can even introduce bias where none existed. Directed acyclic graphs (DAGs) provide a method to select potential confounders and minimize bias in the design and analysis of epidemiological studies. DAGs have been used extensively in expert systems and robotics. Robins (1987) introduced the application of DAGs in epidemiology to overcome shortcomings of traditional methods to control for confounding, especially as they related to unmeasured confounding. DAGs provide a quick and visual way to assess confounding without making parametric assumptions. We introduce DAGs, starting with definitions and rules for basic manipulation, stressing more on applications than theory. We then demonstrate their application in the control of confounding through examples of observational and cross-sectional epidemiological studies.

Quantitative Serum Nuclear Magnetic Resonance Metabolomics in Large-Scale Epidemiology: A Primer on -Omic Technologies

PubMed Central

Kangas, Antti J; Soininen, Pasi; Lawlor, Debbie A; Davey Smith, George; Ala-Korpela, Mika

2017-01-01

Abstract Detailed metabolic profiling in large-scale epidemiologic studies has uncovered novel biomarkers for cardiometabolic diseases and clarified the molecular associations of established risk factors. A quantitative metabolomics platform based on nuclear magnetic resonance spectroscopy has found widespread use, already profiling over 400,000 blood samples. Over 200 metabolic measures are quantified per sample; in addition to many biomarkers routinely used in epidemiology, the method simultaneously provides fine-grained lipoprotein subclass profiling and quantification of circulating fatty acids, amino acids, gluconeogenesis-related metabolites, and many other molecules from multiple metabolic pathways. Here we focus on applications of magnetic resonance metabolomics for quantifying circulating biomarkers in large-scale epidemiology. We highlight the molecular characterization of risk factors, use of Mendelian randomization, and the key issues of study design and analyses of metabolic profiling for epidemiology. We also detail how integration of metabolic profiling data with genetics can enhance drug development. We discuss why quantitative metabolic profiling is becoming widespread in epidemiology and biobanking. Although large-scale applications of metabolic profiling are still novel, it seems likely that comprehensive biomarker data will contribute to etiologic understanding of various diseases and abilities to predict disease risks, with the potential to translate into multiple clinical settings. PMID:29106475

Design and implementation of relational databases relevant to the diverse needs of a tuberculosis case contact study in the Gambia.

PubMed

Jeffries, D J; Donkor, S; Brookes, R H; Fox, A; Hill, P C

2004-09-01

The data requirements of a large multidisciplinary tuberculosis case contact study are complex. We describe an ACCESS-based relational database system that meets our rigorous requirements for data entry and validation, while being user-friendly, flexible, exportable, and easy to install on a network or stand alone system. This includes the development of a double data entry package for epidemiology and laboratory data, semi-automated entry of ELISPOT data directly from the plate reader, and a suite of new programmes for the manipulation and integration of flow cytometry data. The double entered epidemiology and immunology databases are combined into a separate database, providing a near-real-time analysis of immuno-epidemiological data, allowing important trends to be identified early and major decisions about the study to be made and acted on. This dynamic data management model is portable and can easily be applied to other studies.

Earth Observation, Spatial Data Quality, and Neglected Tropical Diseases.

PubMed

Hamm, Nicholas A S; Soares Magalhães, Ricardo J; Clements, Archie C A

2015-12-01

Earth observation (EO) is the use of remote sensing and in situ observations to gather data on the environment. It finds increasing application in the study of environmentally modulated neglected tropical diseases (NTDs). Obtaining and assuring the quality of the relevant spatially and temporally indexed EO data remain challenges. Our objective was to review the Earth observation products currently used in studies of NTD epidemiology and to discuss fundamental issues relating to spatial data quality (SDQ), which limit the utilization of EO and pose challenges for its more effective use. We searched Web of Science and PubMed for studies related to EO and echinococossis, leptospirosis, schistosomiasis, and soil-transmitted helminth infections. Relevant literature was also identified from the bibliographies of those papers. We found that extensive use is made of EO products in the study of NTD epidemiology; however, the quality of these products is usually given little explicit attention. We review key issues in SDQ concerning spatial and temporal scale, uncertainty, and the documentation and use of quality information. We give examples of how these issues may interact with uncertainty in NTD data to affect the output of an epidemiological analysis. We conclude that researchers should give careful attention to SDQ when designing NTD spatial-epidemiological studies. This should be used to inform uncertainty analysis in the epidemiological study. SDQ should be documented and made available to other researchers.

Feasibility of Epidemiologic Research on Nonauditory Health Effects of Residential Aircraft Noise Exposure. Volume 2. Background, General Process Model and Potential Studies

DTIC Science & Technology

1989-01-27

Epidemiologic Study in 120 Oklahoma City 5.4 Chronic Exposure to Sonic Booms 122 5.4.1 White Sands Missile Range 122 5.4.2 Areas Overflown by SR-71 123...5.5 Chronic Exposure to Subsonic Civil Aircraft Noise 123 5.5.1 Design of an Ecologic Study in Airport Environs 124 Iv 5.5.2 Preliminary Evaluation of...dosage-effect relationships for different groups of individuals, one must be able to argue convincingly that a noise measure reflects some aspect of

Making medical decisions in dependence of genetic background: estimation of the utility of DNA testing in clinical, pharmaco-epidemiological or genetic studies.

PubMed

Nguyen, Thuy Trang; Schäfer, Helmut; Timmesfeld, Nina

2013-05-01

An index measuring the utility of testing a DNA marker before deciding between two alternative treatments is proposed which can be estimated from pharmaco-epidemiological case-control or cohort studies. In the case-control design, external estimates of the prevalence of the disease and of the frequency of the genetic risk variant are required for estimating the utility index. Formulas for point and interval estimates are derived. Empirical coverage probabilities of the confidence intervals were estimated under different scenarios of disease prevalence, prevalence of drug use, and population frequency of the genetic variant. To illustrate our method, we re-analyse pharmaco-epidemiological case-control data on oral contraceptive intake and venous thrombosis in carriers and non-carriers of the factor V Leiden mutation. We also re-analyse cross-sectional data from the Framingham study on a gene-diet interaction between an APOA2 polymorphism and high saturated fat intake on obesity. We conclude that the utility index may be helpful to evaluate and appraise the potential clinical and public health relevance of gene-environment interaction effects detected in genomic and candidate gene association studies and may be a valuable decision support for designing prospective studies on the clinical utility. © 2013 Wiley Periodicals, Inc.

75 FR 70274 - Statement of Organization, Functions, and Delegations of Authority

Federal Register 2010, 2011, 2012, 2013, 2014

2010-11-17

... designs to prevent slope and highwall failures; (5) conducts research using a variety of techniques...) designs and conducts epidemiological research studies to identify and classify risk factors that cause, or... the titles and functional statements for the Office of Mine Safety and Health Research (CCM) and...

Accounting for response misclassification and covariate measurement error improves power and reduces bias in epidemiologic studies.

PubMed

Cheng, Dunlei; Branscum, Adam J; Stamey, James D

2010-07-01

To quantify the impact of ignoring misclassification of a response variable and measurement error in a covariate on statistical power, and to develop software for sample size and power analysis that accounts for these flaws in epidemiologic data. A Monte Carlo simulation-based procedure is developed to illustrate the differences in design requirements and inferences between analytic methods that properly account for misclassification and measurement error to those that do not in regression models for cross-sectional and cohort data. We found that failure to account for these flaws in epidemiologic data can lead to a substantial reduction in statistical power, over 25% in some cases. The proposed method substantially reduced bias by up to a ten-fold margin compared to naive estimates obtained by ignoring misclassification and mismeasurement. We recommend as routine practice that researchers account for errors in measurement of both response and covariate data when determining sample size, performing power calculations, or analyzing data from epidemiological studies. 2010 Elsevier Inc. All rights reserved.

Incorporating Measurement Error from Modeled Air Pollution Exposures into Epidemiological Analyses.

PubMed

Samoli, Evangelia; Butland, Barbara K

2017-12-01

Outdoor air pollution exposures used in epidemiological studies are commonly predicted from spatiotemporal models incorporating limited measurements, temporal factors, geographic information system variables, and/or satellite data. Measurement error in these exposure estimates leads to imprecise estimation of health effects and their standard errors. We reviewed methods for measurement error correction that have been applied in epidemiological studies that use model-derived air pollution data. We identified seven cohort studies and one panel study that have employed measurement error correction methods. These methods included regression calibration, risk set regression calibration, regression calibration with instrumental variables, the simulation extrapolation approach (SIMEX), and methods under the non-parametric or parameter bootstrap. Corrections resulted in small increases in the absolute magnitude of the health effect estimate and its standard error under most scenarios. Limited application of measurement error correction methods in air pollution studies may be attributed to the absence of exposure validation data and the methodological complexity of the proposed methods. Future epidemiological studies should consider in their design phase the requirements for the measurement error correction method to be later applied, while methodological advances are needed under the multi-pollutants setting.

Estimation of a partially linear additive model for data from an outcome-dependent sampling design with a continuous outcome

PubMed Central

Tan, Ziwen; Qin, Guoyou; Zhou, Haibo

2016-01-01

Outcome-dependent sampling (ODS) designs have been well recognized as a cost-effective way to enhance study efficiency in both statistical literature and biomedical and epidemiologic studies. A partially linear additive model (PLAM) is widely applied in real problems because it allows for a flexible specification of the dependence of the response on some covariates in a linear fashion and other covariates in a nonlinear non-parametric fashion. Motivated by an epidemiological study investigating the effect of prenatal polychlorinated biphenyls exposure on children's intelligence quotient (IQ) at age 7 years, we propose a PLAM in this article to investigate a more flexible non-parametric inference on the relationships among the response and covariates under the ODS scheme. We propose the estimation method and establish the asymptotic properties of the proposed estimator. Simulation studies are conducted to show the improved efficiency of the proposed ODS estimator for PLAM compared with that from a traditional simple random sampling design with the same sample size. The data of the above-mentioned study is analyzed to illustrate the proposed method. PMID:27006375

Characteristics of the Japanese Diet Described in Epidemiologic Publications: A Qualitative Systematic Review.

PubMed

Suzuki, Nozomu; Goto, Yoshihito; Ota, Haruka; Kito, Kumiko; Mano, Fumika; Joo, Erina; Ikeda, Kaori; Inagaki, Nobuya; Nakayama, Takeo

2018-01-01

International interest in the Japanese diet has grown in recent years. The aim of this systematic review was to evaluate and organize the Japanese diet and dietary characteristics from an epidemiological perspective, mainly focusing on the nutritional and dietary elements. PubMed, Web of Science, Japan Medical Abstracts Society, JDream III, and CiNii databases were searched. The eligibility criteria included research with an epidemiological study design that was either cross-sectional, cohort, or case-control-based that defined the dietary patterns of the Japanese diet using dietary pattern analysis. A total of 39 research articles that described the Japanese diet were included. The data that were extracted included the following: implementing country, location, study design, participant characteristics, key outcomes, methods used in the analysis of dietary patterns, and descriptions of the Japanese diet. As a result of the systematic review analyzing the descriptions of the Japanese diet from 39 selected articles, we were able to aggregate the descriptions into 16 categories from 33 factors. After performing a content analysis using a further aggregation of categories, we found that the top three applicable categories were soybeans/soybean-derived products, seafood, and vegetables; these were followed by rice and miso soup. The Japanese dietary content was found to be diverse based on an examination of epidemiological studies; however, we were able to aggregate the content into 16 categories. The Japanese diet is considered to be a dietary pattern that contains a combination of factors: the dietary staple, side dishes, and soup.

Frequent In-Migration and Highly Focal Transmission of Dengue Viruses among Children in Kamphaeng Phet, Thailand

DTIC Science & Technology

2013-01-17

Maryland, United States of America Introduction Dengue is the leading cause of mosquito-borne viral disease worldwide, and dengue fever (DF) and dengue ...of the spread of dengue virus (DENV) at local scales is central to understanding the epidemiology and evolution of this major human pathogen. We...parents. The study area and design have been described previously [11,12,18]. The epidemiology of dengue is well characterized in this region of

Epidemiology of psychogenic nonepileptic seizures.

PubMed

Asadi-Pooya, Ali A; Sperling, Michael R

2015-05-01

We critically review the existing literature about the epidemiology (i.e., diagnosis, occurrence, age, gender, comorbidity with epilepsy, associated factors, prognosis, mortality, and cost) of psychogenic nonepileptic seizures (PNES) and provide suggestions for future research. Psychogenic nonepileptic seizures are commonly diagnosed at epilepsy centers. The diagnosis of PNES relies on a multidisciplinary evaluation and is usually based on different combinations of data. Recording a seizure, while under video-EEG monitoring, is the most reliable diagnostic test. However, not all patients present with seizures while under video-EEG monitoring. Furthermore, not all epileptic seizures produce visible changes in the scalp EEG. The incidence of PNES was estimated to be 1.4-4.9/100,000/year in three previous studies, and the prevalence was calculated to be between 2 to 33 per 100,000 in one study, making it a significant neuropsychiatric condition. However, there remains a scarcity of data about the epidemiology of PNES, and extant studies that assessed the epidemiological characteristics of PNES have significant limitations. For example, inconsistencies with regard to the age of patients studied and lack of standardization of the diagnostic criteria are some of the significant limitations among studies. In conclusion, PNES merit further epidemiological and pathophysiological investigation. A more precise definition and clear guidance on standards for the diagnosis might influence the direction of future research. Well-designed prospective population-based studies to clarify the epidemiology of PNES in various parts of the world, including an evaluation of the predisposing, precipitating, and perpetuating factors in cross-cultural comparisons is required. Copyright © 2015 Elsevier Inc. All rights reserved.

[Curricular design of health postgraduate programs: the case of Masters in epidemiology].

PubMed

Bobadilla, J L; Lozano, R; Bobadilla, C

1991-01-01

This paper discusses the need to create specific programs for the training of researchers in epidemiology, a field that has traditionally been ignored by the graduate programs in public health. This is due, in part, to the emphasis that has been placed on the training of professionals in other areas of public health. The paper also includes the results of a consensus exercise developed during the curricular design of the Masters Program in Epidemiology of the School of Medicine of the National Autonomous University of Mexico. The technique used during the consensus exercise was the TKJ, which allows the presentation of ideas and possible solutions for a specific problem. This is probably the first published experience in the use of such a technique for the design of an academic curriculum. Taking as a base the general characteristics of the students, the substantive, disciplinary and methodological subjects were chosen. The results showed a need for a multidisciplinary approach based on modern methodologies of statistics and epidemiology. The usefulness of the results of the curricular design and the superiority of this method to reach consensus is also discussed.

The epidemiology of injury among surfers, kite surfers and personal watercraft riders: wind and waves.

PubMed

Pikora, Terri J; Braham, Rebecca; Mills, Christina

2012-01-01

The objective of this review was to summarize the epidemiological literature for surfboard riding (surfing), kite surfing and personal watercraft (PWC) riding injuries and describe the incidence and nature of these injuries, common risk factors, and strategies for prevention. The databases searched for relevant publications included Medline, ScienceDirect, ProQuest International, PubMed, Academic Search Premier as well as Google Scholar to identify additional, non-indexed studies. Overall, there was a lack of good quality descriptive studies for these three sports and many of the studies reviewed involved the use of administrative datasets or case-series designs. Among the few studies to provide incidence estimates, there were inconsistencies in how injury was defined, the inclusion criteria, and the reporting of incidence rates, making comparisons within and between the sports difficult. While the reported incidence rates were generally low, head and lower extremity injuries were common across all three sports. Only two studies reported evidence for postulated risk factors. Bigger waves and surfing over rock or reef sea floor increased the risk of injury among competitive surfers, while older age and having more experience increased the risk of significant injuries among recreational surfers. No evaluations of preventative measures were identified. This review demonstrates the need for well-designed epidemiological research, especially studies that focus on the accurate measurement and description of incidence, nature, severity and circumstances of injuries. Once this has occurred, interventions targeted at reducing the incidence of injuries among these sports can be designed, implemented and evaluated. Copyright © 2012 S. Karger AG, Basel.

Vaccine epidemiology: Its role in promoting sound immunization programs in Japan.

PubMed

Hirota, Yoshio; Ozasa, Kotaro; Nakano, Takashi

2017-08-24

In Japan, the Vaccine Epidemiology Research Group created by the Ministry of Health, Labour and Welfare has played an important role in demonstrating the solid scientific basis for vaccine efficacy and safety since 2002. Members of the group, including epidemiologists, clinicians and microbiologists, have been conducting collaborative studies on vaccines for influenza, pertussis, rotavirus gastroenteritis, polio and pneumonia. So far, the group has achieved several works and contributed to the national vaccination program, including research on the immunogenicity of low doses of influenza vaccine among young children, the immunogenicity and effectiveness of the 2009 influenza pandemic vaccine among various risk groups, the interchangeability of live/inactivated polio vaccines, the health impact of influenza on pregnant women, and the monitoring of influenza vaccine effectiveness using case-control studies with a test-negative design. As part of the 18th Annual Meeting of the Japanese Society of Vaccinology, these accomplishments were featured in the Vaccine Epidemiology Symposium. This report summarizes the recent epidemiological studies on vaccine in Japan as a prologue to the next six papers collected from the symposium. Copyright © 2017 Elsevier Ltd. All rights reserved.

Epidemiology of Injuries and Prevention Strategies in Competitive Swimmers

PubMed Central

Wanivenhaus, Florian; Fox, Alice J. S.; Chaudhury, Salma; Rodeo, Scott A.

2012-01-01

Context: Competitive swimmers are predisposed to musculoskeletal injuries of the upper limb, knee, and spine. This review discusses the epidemiology of these injuries, in addition to prevention strategies that may assist the physician in formulating rehabilitation programs for the swimmer following an injury. Evidence Acquisition: A literature search was performed by a review of Google Scholar, OVID, and PubMed articles published from 1972 to 2011. Results: This study highlights the epidemiology of injuries common to competitive swimmers and provides prevention strategies for the sports health professional. Conclusions: An understanding of swimming biomechanics and typical injuries in swimming aids in early recognition of injury, initiation of treatment, and design of optimal prevention and rehabilitation strategies. PMID:23016094

Reducing random measurement error in assessing postural load on the back in epidemiologic surveys.

PubMed

Burdorf, A

1995-02-01

The goal of this study was to design strategies to assess postural load on the back in occupational epidemiology by taking into account the reliability of measurement methods and the variability of exposure among the workers under study. Intermethod reliability studies were evaluated to estimate the systematic bias (accuracy) and random measurement error (precision) of various methods to assess postural load on the back. Intramethod reliability studies were reviewed to estimate random variability of back load over time. Intermethod surveys have shown that questionnaires have a moderate reliability for gross activities such as sitting, whereas duration of trunk flexion and rotation should be assessed by observation methods or inclinometers. Intramethod surveys indicate that exposure variability can markedly affect the reliability of estimates of back load if the estimates are based upon a single measurement over a certain time period. Equations have been presented to evaluate various study designs according to the reliability of the measurement method, the optimum allocation of the number of repeated measurements per subject, and the number of subjects in the study. Prior to a large epidemiologic study, an exposure-oriented survey should be conducted to evaluate the performance of measurement instruments and to estimate sources of variability for back load. The strategy for assessing back load can be optimized by balancing the number of workers under study and the number of repeated measurements per worker.

Methodological considerations for designing a community water fluoridation cessation study.

PubMed

Singhal, Sonica; Farmer, Julie; McLaren, Lindsay

2017-06-01

High-quality, up-to-date research on community water fluoridation (CWF), and especially on the implications of CWF cessation for dental health, is limited. Although CWF cessation studies have been conducted, they are few in number; one of the major reasons is the methodological complexity of conducting such a study. This article draws on a systematic review of existing cessation studies (n=15) to explore methodological considerations of conducting CWF cessation studies in future. We review nine important methodological aspects (study design, comparison community, target population, time frame, sampling strategy, clinical indicators, assessment criteria, covariates and biomarkers) and provide recommendations for planning future CWF cessation studies that examine effects on dental caries. There is no one ideal study design to answer a research question. However, recommendations proposed regarding methodological aspects to conduct an epidemiological study to observe the effects of CWF cessation on dental caries, coupled with our identification of important methodological gaps, will be useful for researchers who are looking to optimize resources to conduct such a study with standards of rigour. © 2017 Her Majesty the Queen in Right of Canada. Community Dentistry and Oral Epidemiology © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Local health department epidemiologic capacity: a stratified cross-sectional assessment describing the quantity, education, training, and perceived competencies of epidemiologic staff.

PubMed

O'Keefe, Kaitlin A; Shafir, Shira C; Shoaf, Kimberley I

2013-01-01

Local health departments (LHDs) must have sufficient numbers of staff functioning in an epidemiologic role with proper education, training, and skills to protect the health of communities they serve. This pilot study was designed to describe the composition, training, and competency level of LHD staff and examine the hypothesis that potential disparities exist between LHDs serving different sized populations. Cross-sectional surveys were conducted with directors and epidemiologic staff from a sample of 100 LHDs serving jurisdictions of varied sizes. Questionnaires included inquiries regarding staff composition, education, training, and measures of competency modeled on previously conducted studies by the Council of State and Territorial Epidemiologists. Number of epidemiologic staff, academic degree distribution, epidemiologic training, and both director and staff confidence in task competencies were calculated for each LHD size strata. Disparities in measurements were observed in LHDs serving different sized populations. LHDs serving small populations reported a smaller average number of epidemiologic staff than those serving larger jurisdictions. As size of population served increased, percentages of staff and directors holding bachelors' and masters' degrees increased, while those holding RN degrees decreased. A higher degree of perceived competency of staff in most task categories was reported in LHDs serving larger populations. LHDs serving smaller populations reported fewer epidemiologic staff, therefore might benefit from additional resources. Differences observed in staff education, training, and competencies suggest that enhanced epidemiologic training might be particularly needed in LHDs serving smaller populations. RESULTS can be used as a baseline for future research aimed at identifying areas where training and personnel resources might be particularly needed to increase the capabilities of LHDs.

Connection Between Environmental Exposure and Health Outcomes

EPA Pesticide Factsheets

This page gives some examples that show how there is a relationships between environmental exposures and health outcomes which can only be established through well-designed epidemiological, toxicological, and clinical studies.

DEMONSTRATION OF LOW COST, LOW BURDEN EXPOSURE MONITORING STRATEGIES

EPA Science Inventory

This study is designed to develop and demonstrate relevant, low-cost, low-burden monitoring strategies that could be used in large longitudinal exposure/epidemiological studies, such as the National Children's Study. The focus of this study is on (1) recruiting and retaining p...

Photochemical Reaction Altered Cardiac Toxicity of Diesel Exhaust Inhalation

EPA Science Inventory

Rationale: Epidemiological studies have indicated an association between urban air pollution exposure and cardiovascular morbidity and mortality. The present study was designed to evaluate the cardiac effects of inhaled diesel exhaust and compared with photochemically altered d...

Reproductive Outcomes Associated with Noise Exposure — A Systematic Review of the Literature

PubMed Central

Ristovska, Gordana; Laszlo, Helga Elvira; Hansell, Anna L.

2014-01-01

Introduction: High noise exposure during critical periods in gestation is a potential stressor that may result in increased risk of implantation failure, dysregulation of placentation or decrease of uterine blood flow. This paper systematically reviews published evidence on associations between reproductive outcomes and occupational and environmental noise exposure. Methods: The Web of Science, PubMed and Embase electronic databases were searched for papers published between 1970 to June 2014 and via colleagues. We included 14 epidemiological studies related to occupational noise exposure and nine epidemiological studies related to environmental noise exposure. There was some evidence for associations between occupational noise exposure and low birthweight, preterm birth and small for gestational age, either independently or together with other occupational risk factors. Five of six epidemiologic studies, including the two largest studies, found significant associations between lower birthweight and higher noise exposure. There were few studies on other outcomes and study design issues may have led to bias in assessments in some studies. Conclusions: There is evidence for associations between noise exposure and adverse reproductive outcomes from animal studies. Few studies in have been conducted in humans but there is some suggestive evidence of adverse associations with environmental noise from both occupational and epidemiological studies, especially for low birthweight. PMID:25101773

EXPOSURE ANALYSIS FROM PERSONAL AND AMBIENT AIR SAMPLING: RESULTS OF THE 1998 BALTIMORE STUDY

EPA Science Inventory

An integrated epidemiological-exposure panel study was conducted during July-August 1998 which focused upon establishing relationships between potential human exposures to particulate matter (PM) and related co-pollutants with detectable health effects. The study design incorpo...

Trends in employer postings for epidemiology jobs: an analysis of PublicHealthJobs.net data from 2003 to 2016.

PubMed

Frankenfeld, Cara L

2017-09-01

To analyze public health job posting data to help objectively inform epidemiology faculty and students about skills sought by employers. Raw data from PublicHealthJobs.net database (January 2003-October 2016) was data-mined and analyzed (n = 25,308 job postings). There were 3985 jobs that were classified with an epidemiology designation, either as the only designation or co-occurring with another designation. Frequencies and percentages were calculated for job type, industry, location, degree requirements, CPH credential, and specialized skills. The majority of recent postings (January 2014-October 2016) were for full-time positions (60.8%). The highest proportion of recent job industries was education/academic/research (44.3%), state government (17.5%), and nonprofit/NGO (16.3%). A masters-level degree was listed in 71.4% of postings, frequently co-occurring with other degree levels. Epidemiology as the only job class was listed in 1765 postings (45.3%). Most characteristics of epidemiology job postings did not appreciably change over the time period, but there were some specialized skill differences. This analysis illustrates how employment sites can be used to identify employer preferences in epidemiology hires. There may be some skills that are beneficial additions to public health curricula or that job-seeking future epidemiologists may wish to enhance during their training. Copyright © 2017 Elsevier Inc. All rights reserved.

Strong and Flexible: Developing a Three-Tiered Curriculum for the Regional Central America Field Epidemiology Training Program

PubMed Central

Traicoff, Denise A.; Suarez-Rangel, Gloria; Espinosa-Wilkins, Yescenia; Lopez, Augusto; Diaz, Anaite; Caceres, Victor

2017-01-01

Field Epidemiology Training Programs (FETPs) are recognized worldwide as an effective means to strengthen countries’ capacity in epidemiology, surveillance, and outbreak response. FETPs are field-based, with minimum classroom time and maximum time in the field, providing public health services while participants achieve competency. The Central America FETP (CAFETP) uses a three-level pyramid model: basic, intermediate, and advanced. In 2006, a multidisciplinary team used a methodical process based on adult learning practices to construct a competency-based curriculum for the CAFETP. The curriculum was designed based on the tasks related to disease surveillance and field epidemiology that public health officers would conduct at multiple levels in the system. The team used a design process that engaged subject matter experts and considered the unique perspective of each country. The designers worked backwards from the competencies to define field activities, evaluation methods, and classroom components. The 2006 pyramid curriculum has been accredited for a master’s of science in field epidemiology by the Universidad del Valle de Guatemala and has been adapted by programs around the world. The team found the time and effort spent to familiarize subject matter experts with key adult learning principles was worthwhile because it provided a common framework to approach curriculum design. Early results of the redesigned curriculum indicate that the CAFETP supports consistent quality while allowing for specific country needs. PMID:28702503

[Methodological problems in the scientific research on HIV /AIDS in Bolivia].

PubMed

Hita, Susana Ramírez

2013-05-01

This paper discusses the methodological problems in the scientific research on HIV/AIDS in Bolivia, both in the areas of epidemiology and social sciences. Studies associated with this research served as the basis for the implementation of health programs run by The Global Fund, The Pan-American Health Organization, International Cooperation, Non-Governmental Organizations and the Bolivian Ministry of Health and Sports. An analysis of the methodological contradictions and weaknesses was made by reviewing the bibliography of the studies and by conducting qualitative methodological research, that was focused on the quality of health care available to people living with HIV/AIDS in public hospitals and health centers, and looked at how programs targeted at this sector of the population are designed and delivered. In this manner, it was possible to observe the shortcomings of the methodological design in the epidemiological and social science studies which serve as the basis for the implementation of these health programs.

38 CFR 1.17 - Evaluation of studies relating to health effects of radiation exposure.

Code of Federal Regulations, 2012 CFR

2012-07-01

... health effects of radiation exposure. (a) From time to time, the Secretary shall publish evaluations of... paragraph a valid study is one which: (i) Has adequately described the study design and methods of data... studies affecting epidemiological assessments including case series, correlational studies and studies...

38 CFR 1.17 - Evaluation of studies relating to health effects of radiation exposure.

Code of Federal Regulations, 2013 CFR

2013-07-01

... health effects of radiation exposure. (a) From time to time, the Secretary shall publish evaluations of... paragraph a valid study is one which: (i) Has adequately described the study design and methods of data... studies affecting epidemiological assessments including case series, correlational studies and studies...

38 CFR 1.17 - Evaluation of studies relating to health effects of radiation exposure.

Code of Federal Regulations, 2014 CFR

2014-07-01

... health effects of radiation exposure. (a) From time to time, the Secretary shall publish evaluations of... paragraph a valid study is one which: (i) Has adequately described the study design and methods of data... studies affecting epidemiological assessments including case series, correlational studies and studies...

38 CFR 1.17 - Evaluation of studies relating to health effects of radiation exposure.

Code of Federal Regulations, 2010 CFR

2010-07-01

... health effects of radiation exposure. (a) From time to time, the Secretary shall publish evaluations of... paragraph a valid study is one which: (i) Has adequately described the study design and methods of data... studies affecting epidemiological assessments including case series, correlational studies and studies...

38 CFR 1.17 - Evaluation of studies relating to health effects of radiation exposure.

Code of Federal Regulations, 2011 CFR

2011-07-01

... health effects of radiation exposure. (a) From time to time, the Secretary shall publish evaluations of... paragraph a valid study is one which: (i) Has adequately described the study design and methods of data... studies affecting epidemiological assessments including case series, correlational studies and studies...

The Epidemiology of Hand, Foot and Mouth Disease in Asia

PubMed Central

Koh, Wee Ming; Bogich, Tiffany; Siegel, Karen; Jin, Jing; Chong, Elizabeth Y.; Tan, Chong Yew; Chen, Mark IC; Horby, Peter

2016-01-01

Context: Hand, foot and mouth disease (HFMD) is a widespread pediatric disease caused primarily by human enterovirus 71 (EV-A71) and Coxsackievirus A16 (CV-A16). Objective: This study reports a systematic review of the epidemiology of HFMD in Asia. Data Sources: PubMed, Web of Science and Google Scholar were searched up to December 2014. Study Selection: Two reviewers independently assessed studies for epidemiologic and serologic information about prevalence and incidence of HFMD against predetermined inclusion/exclusion criteria. Data Extraction: Two reviewers extracted answers for 8 specific research questions on HFMD epidemiology. The results are checked by 3 others. Results: HFMD is found to be seasonal in temperate Asia with a summer peak and in subtropical Asia with spring and fall peaks, but not in tropical Asia; evidence of a climatic role was identified for temperate Japan. Risk factors for HFMD include hygiene, age, gender and social contacts, but most studies were underpowered to adjust rigorously for confounding variables. Both community-level and school-level transmission have been implicated, but their relative importance for HFMD is inconclusive. Epidemiologic indices are poorly understood: No supporting quantitative evidence was found for the incubation period of EV-A71; the symptomatic rate of EV-A71/Coxsackievirus A16 infection was from 10% to 71% in 4 studies; while the basic reproduction number was between 1.1 and 5.5 in 3 studies. The uncertainty in these estimates inhibits their use for further analysis. Limitations: Diversity of study designs complicates attempts to identify features of HFMD epidemiology. Conclusions: Knowledge on HFMD remains insufficient to guide interventions such as the incorporation of an EV-A71 vaccine in pediatric vaccination schedules. Research is urgently needed to fill these gaps. PMID:27273688

Diesel Exhaust Exposure and the Risk of Lung Cancer—A Review of the Epidemiological Evidence

PubMed Central

Sun, Yi; Bochmann, Frank; Nold, Annette; Mattenklott, Markus

2014-01-01

To critically evaluate the association between diesel exhaust (DE) exposure and the risk of lung cancer, we conducted a systematic review of published epidemiological evidences. To comprehensively identify original studies on the association between DE exposure and the risk of lung cancer, literature searches were performed in literature databases for the period between 1970 and 2013, including bibliographies and cross-referencing. In total, 42 cohort studies and 32 case-control studies were identified in which the association between DE exposures and lung cancer was examined. In general, previous studies suffer from a series of methodological limitations, including design, exposure assessment methods and statistical analysis used. A lack of objective exposure information appears to be the main problem in interpreting epidemiological evidence. To facilitate the interpretation and comparison of previous studies, a job-exposure matrix (JEM) of DE exposures was created based on around 4,000 historical industrial measurements. The values from the JEM were considered during interpretation and comparison of previous studies. Overall, neither cohort nor case-control studies indicate a clear exposure-response relationship between DE exposure and lung cancer. Epidemiological studies published to date do not allow a valid quantification of the association between DE and lung cancer. PMID:24473109

Inhalation of Photochemically Altered Urban Mixtures Depresses Cardiac Function in Mice

EPA Science Inventory

Rationale: Epidemiological studies have indicated an association between urban air pollution exposure and cardiovascular morbidity and mortality. The present study was designed to evaluate the cardiac effects of inhaled photochemical products in urban mixtures in a murine model. ...

Prophylactic Knee Braces: Where Do They Stand?

ERIC Educational Resources Information Center

McCarthy, Paul

1988-01-01

The effectiveness of knee braces in preventing knee injuries in football is inconclusive. This article reviews research from epidemiologic, cadaver, and surrogate studies; discusses reasons for conflicting study results, including research design problems; and describes alternative approaches that have been suggested. (IAH)

[Clinical research=design*measurements*statistical analyses].

PubMed

Furukawa, Toshiaki

2012-06-01

A clinical study must address true endpoints that matter for the patients and the doctors. A good clinical study starts with a good clinical question. Formulating a clinical question in the form of PECO can sharpen one's original question. In order to perform a good clinical study one must have a knowledge of study design, measurements and statistical analyses: The first is taught by epidemiology, the second by psychometrics and the third by biostatistics.

Jumping on the Train of Personalized Medicine: A Primer for Non-Geneticist Clinicians: Part 2. Fundamental Concepts in Genetic Epidemiology.

PubMed

Li, Aihua; Meyre, David

2014-05-01

With the decrease in sequencing costs, personalized genome sequencing will eventually become common in medical practice. We therefore write this series of three reviews to help non-geneticist clinicians to jump into the fast-moving field of personalized medicine. In the first article of this series, we reviewed the fundamental concepts in molecular genetics. In this second article, we cover the key concepts and methods in genetic epidemiology including the classification of genetic disorders, study designs and their implementation, genetic marker selection, genotyping and sequencing technologies, gene identification strategies, data analyses and data interpretation. This review will help the reader critically appraise a genetic association study. In the next article, we will discuss the clinical applications of genetic epidemiology in the personalized medicine area.

Best Practices for Gauging Evidence of Causality in Air Pollution Epidemiology.

PubMed

Dominici, Francesca; Zigler, Corwin

2017-12-15

The contentious political climate surrounding air pollution regulations has brought some researchers and policy-makers to argue that evidence of causality is necessary before implementing more stringent regulations. Recently, investigators in an increasing number of air pollution studies have purported to have used "causal analysis," generating the impression that studies not explicitly labeled as such are merely "associational" and therefore less rigorous. Using 3 prominent air pollution studies as examples, we review good practices for how to critically evaluate the extent to which an air pollution study provides evidence of causality. We argue that evidence of causality should be gauged by a critical evaluation of design decisions such as 1) what actions or exposure levels are being compared, 2) whether an adequate comparison group was constructed, and 3) how closely these design decisions approximate an idealized randomized study. We argue that air pollution studies that are more scientifically rigorous in terms of the decisions made to approximate a randomized experiment are more likely to provide evidence of causality and should be prioritized among the body of evidence for regulatory review accordingly. Our considerations, although presented in the context of air pollution epidemiology, can be broadly applied to other fields of epidemiology. © The Author(s) 2017. Published by Oxford University Press on behalf of the Johns Hopkins Bloomberg School of Public Health. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

75 FR 14170 - Medical Device Epidemiology Network: Developing Partnership Between the Center for Devices and...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-03-24

... methods for medical device comparative analyses, best practices and best design and analysis methods. II... the performance of medical devices (including comparative effectiveness studies). The centers...

Study designs may influence results: the problems with questionnaire-based case-control studies on the epidemiology of glioma.

PubMed

Johansen, Christoffer; Schüz, Joachim; Andreasen, Anne-Marie Serena; Dalton, Susanne Oksbjerg

2017-03-28

Glioma is a rare brain tumour with a very poor prognosis and the search for modifiable factors is intense. We reviewed the literature concerning risk factors for glioma obtained in case-control designed epidemiological studies in order to discuss the influence of this methodology on the observed results. When reviewing the association between three exposures, medical radiation, exogenous hormone use and allergy, we critically appraised the evidence from both case-control and cohort studies. For medical radiation and hormone replacement therapy (HRT), questionnaire-based case-control studies appeared to show an inverse association, whereas nested case-control and cohort studies showed no association. For allergies, the inverse association was observed irrespective of study design. We recommend that the questionnaire-based case-control design be placed lower in the hierarchy of studies for establishing cause-and-effect for diseases such as glioma. We suggest that a state-of-the-art case-control study should, as a minimum, be accompanied by extensive validation of the exposure assessment methods and the representativeness of the study sample with regard to the exposures of interest. Otherwise, such studies cannot be regarded as 'hypothesis testing' but only 'hypothesis generating'. We consider that this holds true for all questionnaire-based case-control studies on cancer and other chronic diseases, although perhaps not to the same extent for each exposure-outcome combination.

Does knowledge of seat design and whiplash injury mechanisms translate to understanding outcomes?

PubMed

Ivancic, Paul C

2011-12-01

Review of whiplash injury mechanisms and effects of anti-whiplash systems including active head restraint (AHR) and Whiplash Protection System (WHIPS). This article provides an overview of previous biomechanical and epidemiological studies of AHR and WHIPS and investigates whether seat design and biomechanical knowledge of proposed whiplash injury mechanisms translates to understanding outcomes of rear crash occupants. In attempt to reduce whiplash injuries, some newer automobiles incorporate anti-whiplash systems such as AHR or WHIPS. During a rear crash, mechanically based systems activate by occupant momentum pressing into the seatback whereas electronically based systems activate using crash sensors and an electronic control unit linked to the head restraint. To investigate the effects of AHR and WHIPS on occupant responses including head and neck loads and motions, biomechanical studies of simulated rear crashes have been performed using human volunteers, mathematical models, crash dummies, whole cadavers, and hybrid cadaveric/surrogate models. Epidemiological studies have evaluated the effects of AHR and WHIPS on reducing whiplash injury claims and lessening subjective complaints of neck pain after rear crashes. RESULTS.: Biomechanical studies indicate that AHR and WHIPS reduced the potential for some whiplash injuries but did not completely eliminate the injury risk. Epidemiological outcomes indicate reduced whiplash injury claims or subjective complaints of crash-related neck pain between 43 and 75% due to AHR and between 21% and 49% due to WHIPS as compared to conventional seats and head restraints. Yielding energy-absorbing seats aim to reduce occupant loads and accelerations whereas AHRs aim to provide early head support to minimize head and neck motions. Continued objective biomechanical and epidemiological studies of anti-whiplash systems together with industry, governmental, and clinical initiatives will ultimately lead to reduced whiplash injuries through improved prevention strategies.

Capacity Building in Response to Pandemic Influenza Threats: Lao PDR Case Study

PubMed Central

Phommasack, Bounlay; Moen, Ann; Vongphrachanh, Phengta; Tsuyuoka, Reiko; Cox, Nancy; Khamphaphongphanh, Bouaphanh; Phonekeo, Darouny; Kasai, Takeshi; Ketmayoon, Pakapak; Lewis, Hannah; Kounnavong, Bounheuang; Khanthamaly, Viengphone; Corwin, Andrew

2012-01-01

The Lao People's Democratic Republic (PDR) committed to pandemic detection and response preparations when faced with the threat of avian influenza. Since 2006, the National Center for Laboratory and Epidemiology of Lao PDR has developed credible laboratory, surveillance, and epidemiological (human) capacity and as a result was designated a World Health Organization National Influenza Center in 2010. The Lao PDR experience in building influenza capacities provides a case study of the considerable crossover effect of such investments to augment the capacity to combat emerging and re-emerging diseases other than influenza. PMID:23222137

The Epidemiology of Injuries Across the Weight-Training Sports.

PubMed

Keogh, Justin W L; Winwood, Paul W

2017-03-01

Weight-training sports, including weightlifting, powerlifting, bodybuilding, strongman, Highland Games, and CrossFit, are weight-training sports that have separate divisions for males and females of a variety of ages, competitive standards, and bodyweight classes. These sports may be considered dangerous because of the heavy loads commonly used in training and competition. Our objective was to systematically review the injury epidemiology of these weight-training sports, and, where possible, gain some insight into whether this may be affected by age, sex, competitive standard, and bodyweight class. We performed an electronic search using PubMed, SPORTDiscus, CINAHL, and Embase for injury epidemiology studies involving competitive athletes in these weight-training sports. Eligible studies included peer-reviewed journal articles only, with no limit placed on date or language of publication. We assessed the risk of bias in all studies using an adaption of the musculoskeletal injury review method. Only five of the 20 eligible studies had a risk of bias score ≥75 %, meaning the risk of bias in these five studies was considered low. While 14 of the studies had sample sizes >100 participants, only four studies utilized a prospective design. Bodybuilding had the lowest injury rates (0.12-0.7 injuries per lifter per year; 0.24-1 injury per 1000 h), with strongman (4.5-6.1 injuries per 1000 h) and Highland Games (7.5 injuries per 1000 h) reporting the highest rates. The shoulder, lower back, knee, elbow, and wrist/hand were generally the most commonly injured anatomical locations; strains, tendinitis, and sprains were the most common injury type. Very few significant differences in any of the injury outcomes were observed as a function of age, sex, competitive standard, or bodyweight class. While the majority of the research we reviewed utilized retrospective designs, the weight-training sports appear to have relatively low rates of injury compared with common team sports. Future weight-training sport injury epidemiology research needs to be improved, particularly in terms of the use of prospective designs, diagnosis of injury, and changes in risk exposure.

The Epidemiology of Hand, Foot and Mouth Disease in Asia: A Systematic Review and Analysis.

PubMed

Koh, Wee Ming; Bogich, Tiffany; Siegel, Karen; Jin, Jing; Chong, Elizabeth Y; Tan, Chong Yew; Chen, Mark Ic; Horby, Peter; Cook, Alex R

2016-10-01

Hand, foot and mouth disease (HFMD) is a widespread pediatric disease caused primarily by human enterovirus 71 (EV-A71) and Coxsackievirus A16 (CV-A16). This study reports a systematic review of the epidemiology of HFMD in Asia. PubMed, Web of Science and Google Scholar were searched up to December 2014. Two reviewers independently assessed studies for epidemiologic and serologic information about prevalence and incidence of HFMD against predetermined inclusion/exclusion criteria. Two reviewers extracted answers for 8 specific research questions on HFMD epidemiology. The results are checked by 3 others. HFMD is found to be seasonal in temperate Asia with a summer peak and in subtropical Asia with spring and fall peaks, but not in tropical Asia; evidence of a climatic role was identified for temperate Japan. Risk factors for HFMD include hygiene, age, gender and social contacts, but most studies were underpowered to adjust rigorously for confounding variables. Both community-level and school-level transmission have been implicated, but their relative importance for HFMD is inconclusive. Epidemiologic indices are poorly understood: No supporting quantitative evidence was found for the incubation period of EV-A71; the symptomatic rate of EV-A71/Coxsackievirus A16 infection was from 10% to 71% in 4 studies; while the basic reproduction number was between 1.1 and 5.5 in 3 studies. The uncertainty in these estimates inhibits their use for further analysis. Diversity of study designs complicates attempts to identify features of HFMD epidemiology. Knowledge on HFMD remains insufficient to guide interventions such as the incorporation of an EV-A71 vaccine in pediatric vaccination schedules. Research is urgently needed to fill these gaps.

Random Amplified Polymorphic DNA PCR in the Teaching of Molecular Epidemiology

ERIC Educational Resources Information Center

Reinoso, Elina B.; Bettera, Susana G.

2016-01-01

In this article, we describe a basic practical laboratory designed for fifth-year undergraduate students of Microbiology as part of the Epidemiology course. This practice provides the students with the tools for molecular epidemiological analysis of pathogenic microorganisms using a rapid and simple PCR technique. The aim of this work was to assay…

Risk factors associated with asbestos-related diseases: a community-based case–control study

PubMed Central

2013-01-01

Background Asbestos is a first level carcinogen. However, few epidemiological studies analyse the risk and protective factors associated with asbestos-related diseases and follow up these conditions in the general population. Pleural mesothelioma, caused by inhalation of asbestos fibres at work, at home or in the environment, is the most representative asbestos-related disease. The objectives of this study are to analyse the risk and protective factors associated with asbestos-related diseases and to investigate the incidence of new clinical manifestations in patients already diagnosed with some form of ARD. Methods/Design We have designed a matched case–control study with follow up of both cohorts from a population of a health district of the Barcelona province that has been exposed to asbestos for a period of 90 years. Discussion A better understanding of asbestos-related diseases should improve i) the clinical and epidemiological follow up of patients with this condition; ii) the design of new treatment strategies; iii) and the development of preventive activities. At the end of the study, the two cohorts created in this study (affected cases and healthy controls) will constitute the basis for future research. PMID:23915043

Genetic Epidemiology and Public Health: The Evolution From Theory to Technology.

PubMed

Fallin, M Daniele; Duggal, Priya; Beaty, Terri H

2016-03-01

Genetic epidemiology represents a hybrid of epidemiologic designs and statistical models that explicitly consider both genetic and environmental risk factors for disease. It is a relatively new field in public health; the term was first coined only 35 years ago. In this short time, the field has been through a major evolution, changing from a field driven by theory, without the technology for genetic measurement or computational capacity to apply much of the designs and methods developed, to a field driven by rapidly expanding technology in genomic measurement and computational analyses while epidemiologic theory struggles to keep up. In this commentary, we describe 4 different eras of genetic epidemiology, spanning this evolution from theory to technology, what we have learned, what we have added to the broader field of public health, and what remains to be done. © The Author 2016. Published by Oxford University Press on behalf of the Johns Hopkins Bloomberg School of Public Health. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

The Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) Statement: guidelines for reporting observational studies.

PubMed

von Elm, Erik; Altman, Douglas G; Egger, Matthias; Pocock, Stuart J; Gøtzsche, Peter C; Vandenbroucke, Jan P

2014-12-01

Much biomedical research is observational. The reporting of such research is often inadequate, which hampers the assessment of its strengths and weaknesses and of a study's generalisability. The Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) Initiative developed recommendations on what should be included in an accurate and complete report of an observational study. We defined the scope of the recommendations to cover three main study designs: cohort, case-control, and cross-sectional studies. We convened a 2-day workshop in September 2004, with methodologists, researchers, and journal editors to draft a checklist of items. This list was subsequently revised during several meetings of the coordinating group and in e-mail discussions with the larger group of STROBE contributors, taking into account empirical evidence and methodological considerations. The workshop and the subsequent iterative process of consultation and revision resulted in a checklist of 22 items (the STROBE Statement) that relate to the title, abstract, introduction, methods, results, and discussion sections of articles. 18 items are common to all three study designs and four are specific for cohort, case-control, or cross-sectional studies. A detailed Explanation and Elaboration document is published separately and is freely available on the Web sites of PLoS Medicine, Annals of Internal Medicine, and Epidemiology. We hope that the STROBE Statement will contribute to improving the quality of reporting of observational studies. Copyright © 2014 The Authors. Published by Elsevier Ltd.. All rights reserved.

Preliminary report from the World Health Organisation Chest Radiography in Epidemiological Studies project.

PubMed

Mahomed, Nasreen; Fancourt, Nicholas; de Campo, John; de Campo, Margaret; Akano, Aliu; Cherian, Thomas; Cohen, Olivia G; Greenberg, David; Lacey, Stephen; Kohli, Neera; Lederman, Henrique M; Madhi, Shabir A; Manduku, Veronica; McCollum, Eric D; Park, Kate; Ribo-Aristizabal, Jose Luis; Bar-Zeev, Naor; O'Brien, Katherine L; Mulholland, Kim

2017-10-01

Childhood pneumonia is among the leading infectious causes of mortality in children younger than 5 years of age globally. Streptococcus pneumoniae (pneumococcus) is the leading infectious cause of childhood bacterial pneumonia. The diagnosis of childhood pneumonia remains a critical epidemiological task for monitoring vaccine and treatment program effectiveness. The chest radiograph remains the most readily available and common imaging modality to assess childhood pneumonia. In 1997, the World Health Organization Radiology Working Group was established to provide a consensus method for the standardized definition for the interpretation of pediatric frontal chest radiographs, for use in bacterial vaccine efficacy trials in children. The definition was not designed for use in individual patient clinical management because of its emphasis on specificity at the expense of sensitivity. These definitions and endpoint conclusions were published in 2001 and an analysis of observer variation for these conclusions using a reference library of chest radiographs was published in 2005. In response to the technical needs identified through subsequent meetings, the World Health Organization Chest Radiography in Epidemiological Studies (CRES) project was initiated and is designed to be a continuation of the World Health Organization Radiology Working Group. The aims of the World Health Organization CRES project are to clarify the definitions used in the World Health Organization defined standardized interpretation of pediatric chest radiographs in bacterial vaccine impact and pneumonia epidemiological studies, reinforce the focus on reproducible chest radiograph readings, provide training and support with World Health Organization defined standardized interpretation of chest radiographs and develop guidelines and tools for investigators and site staff to assist in obtaining high-quality chest radiographs.

Methodological considerations in observational comparative effectiveness research for implantable medical devices: an epidemiologic perspective.

PubMed

Jalbert, Jessica J; Ritchey, Mary Elizabeth; Mi, Xiaojuan; Chen, Chih-Ying; Hammill, Bradley G; Curtis, Lesley H; Setoguchi, Soko

2014-11-01

Medical devices play a vital role in diagnosing, treating, and preventing diseases and are an integral part of the health-care system. Many devices, including implantable medical devices, enter the market through a regulatory pathway that was not designed to assure safety and effectiveness. Several recent studies and high-profile device recalls have demonstrated the need for well-designed, valid postmarketing studies of medical devices. Medical device epidemiology is a relatively new field compared with pharmacoepidemiology, which for decades has been developed to assess the safety and effectiveness of medications. Many methodological considerations in pharmacoepidemiology apply to medical device epidemiology. Fundamental differences in mechanisms of action and use and in how exposure data are captured mean that comparative effectiveness studies of medical devices often necessitate additional and different considerations. In this paper, we discuss some of the most salient issues encountered in conducting comparative effectiveness research on implantable devices. We discuss special methodological considerations regarding the use of data sources, exposure and outcome definitions, timing of exposure, and sources of bias. © The Author 2014. Published by Oxford University Press on behalf of the Johns Hopkins Bloomberg School of Public Health. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Ultrafine ambient particulate matter enhances cardiac ischemia and reperfusion injury

EPA Science Inventory

Epidemiological studies have demonstrated a consistent link between exposure to ambient particulate air pollutant (PM) and the incidence of cardiovascular morbidity and mortality. The present study was designed to evaluate the cardiac effects of ambient PM. Mice were exposed to 1...

DEMONSTRATION OF LOW COST, LOW BURDEN EXPOSURE MONITORING STRATEGIES - BIRTH COHORT

EPA Science Inventory

This study was designed to develop and demonstrate relevant, low cost, low burden monitoring strategies that can be used in a longitudinal epidemiological study that focuses on pregnant women and young children. The focus of this study was on (1) recruiting and retaining partici...

Potential for adult-based epidemiological studies to characterize overall cancer risks associated with a lifetime of CT scans.

PubMed

Shuryak, Igor; Lubin, Jay H; Brenner, David J

2014-06-01

Recent epidemiological studies have suggested that radiation exposure from pediatric CT scanning is associated with small excess cancer risks. However, the majority of CT scans are performed on adults, and most radiation-induced cancers appear during middle or old age, in the same age range as background cancers. Consequently, a logical next step is to investigate the effects of CT scanning in adulthood on lifetime cancer risks by conducting adult-based, appropriately designed epidemiological studies. Here we estimate the sample size required for such studies to detect CT-associated risks. This was achieved by incorporating different age-, sex-, time- and cancer type-dependent models of radiation carcinogenesis into an in silico simulation of a population-based cohort study. This approach simulated individual histories of chest and abdominal CT exposures, deaths and cancer diagnoses. The resultant sample sizes suggest that epidemiological studies of realistically sized cohorts can detect excess lifetime cancer risks from adult CT exposures. For example, retrospective analysis of CT exposure and cancer incidence data from a population-based cohort of 0.4 to 1.3 million (depending on the carcinogenic model) CT-exposed UK adults, aged 25-65 in 1980 and followed until 2015, provides 80% power for detecting cancer risks from chest and abdominal CT scans.

Assessing the perceptions of a biostatistics and epidemiology module: views of Year 2 medical students from a Malaysian university. A cross-sectional survey.

PubMed

Daher, Aqil M; Amin, Farzana

2010-05-13

In the era of evidence based medicine, biostatistics and epidemiology are considered as the main elements aiding the health professional to design a research study, understand the literature, and make decisions about patient care. The aim of the study is to explore students' perception about this subject because it plays an important role in determining educational outcome. Data were collected from a self-administered questionnaire distributed among 164 Year 2 medical students. The 5-point Likert scale anchored by Strongly disagree = 1 and Strongly agree = 5 included 36 questions in four domains designed to assess the perception of a biostatistics and epidemiology module amongst students. 138 students with ages ranging from 20 to 24 years (Mean = 20.7; SD = 0.62) returned their responses to the questionnaire. This was a response rate of 84.14%. Of the 138 students, 80.7% realized the relevance of the subject to real health issues at the end of the module, while 89.8% believed the module focused on interpretation more than calculation.More than three quarters (78.1%) agreed that lack of practicing exercises was the cause for declining interest in the subject, while only 26.1% believed that lectures were not interesting. Another three quarters (75.4%) believed that there were too many lectures for one day of teaching activities, while 84.6% recommended practical sessions for designing research and data collection. This study found that students perceived the relevance of biostatistics and epidemiology to real health issues. The major cause of poor interest in the subject was attributed to the short duration of the course, lack of practicing exercises, and the need for practical data collection sessions. Emphasis should be given to early introduction of projects for data collection and analysis.

The Global Epidemiologic Transition: Noncommunicable Diseases and Emerging Health Risk of Allergic Disease in Sub-Saharan Africa.

PubMed

Atiim, George A; Elliott, Susan J

2016-04-01

Globally, there has been a shift in the causes of illness and death from infectious diseases to noncommunicable diseases. This changing pattern has been attributed to the effects of an (ongoing) epidemiologic transition. Although researchers have applied epidemiologic transition theory to questions of global health, there have been relatively few studies exploring its relevance especially in the context of emerging allergic disorders in sub-Saharan Africa (SSA). In this article, we address the growing burden of noncommunicable diseases in sub-Saharan Africa through the lens of epidemiologic transition theory. After a brief review of the literature on the evolution of the epidemiologic transition with a particular emphasis on sub-Saharan Africa, we discuss existing frameworks designed to help inform our understanding of changing health trends in the developing world. We subsequently propose a framework that privileges "place" as a key construct informing our understanding. In so doing, we use the example of allergic disease, one of the fastest growing chronic conditions in most parts of the world. © 2015 Society for Public Health Education.

Landmarks in the history of cancer epidemiology.

PubMed

Greenwald, Peter; Dunn, Barbara K

2009-03-15

The application of epidemiology to cancer prevention is relatively new, although observations of the potential causes of cancer have been reported for more than 2,000 years. Cancer was generally considered incurable until the late 19th century. Only with a refined understanding of the nature of cancer and strategies for cancer treatment could a systematic approach to cancer prevention emerge. The 20th century saw the elucidation of clues to cancer causation from observed associations with population exposures to tobacco, diet, environmental chemicals, and other exogenous factors. With repeated confirmation of such associations, researchers entertained for the first time the possibility that cancer, like many of the infectious diseases of the time, might be prevented. By the mid-20th century, with antibiotics successfully addressing the majority of infectious diseases and high blood pressure treatment beginning to affect the prevalence of heart disease in a favorable direction, the focus of much of epidemiology shifted to cancer. The early emphasis was on exploring, in greater depth, the environmental, dietary, hormonal, and other exogenous exposures for their potential associations with increased cancer risk. The first major breakthrough in identifying a modifiable cancer risk factor was the documentation of an association between tobacco smoking and lung cancer. During the past four decades, epidemiologic studies have generated population data identifying risk factors for cancers at almost every body site, with many cancers having multiple risk factors. The development of technologies to identify biological molecules has facilitated the incorporation of these molecular manifestations of biological variation into epidemiologic studies, as markers of exposure as well as putative surrogate markers of cancer outcome. This technological trend has, during the past two decades, culminated in emphasis on the identification of genetic variants and their products as correlates of cancer risk, in turn, creating opportunities to incorporate the discipline of molecular/genetic epidemiology into the study of cancer prevention. Epidemiology will undoubtedly continue contributing to cancer prevention by using traditional epidemiologic study designs to address broad candidate areas of interest, with molecular/genetic epidemiology investigations honing in on promising areas to identify specific factors that can be modified with the goal of reducing risk.

Variation in choice of study design: findings from the Epidemiology Design Decision Inventory and Evaluation (EDDIE) survey.

PubMed

Stang, Paul E; Ryan, Patrick B; Overhage, J Marc; Schuemie, Martijn J; Hartzema, Abraham G; Welebob, Emily

2013-10-01

Researchers using observational data to understand drug effects must make a number of analytic design choices that suit the characteristics of the data and the subject of the study. Review of the published literature suggests that there is a lack of consistency even when addressing the same research question in the same database. To characterize the degree of similarity or difference in the method and analysis choices made by observational database research experts when presented with research study scenarios. On-line survey using research scenarios on drug-effect studies to capture method selection and analysis choices that follow a dependency branching based on response to key questions. Voluntary participants experienced in epidemiological study design solicited for participation through registration on the Observational Medical Outcomes Partnership website, membership in particular professional organizations, or links in relevant newsletters. Description (proportion) of respondents selecting particular methods and making specific analysis choices based on individual drug-outcome scenario pairs. The number of questions/decisions differed based on stem questions of study design, time-at-risk, outcome definition, and comparator. There is little consistency across scenarios, by drug or by outcome of interest, in the decisions made for design and analyses in scenarios using large healthcare databases. The most consistent choice was the cohort study design but variability in the other critical decisions was common. There is great variation among epidemiologists in the design and analytical choices that they make when implementing analyses in observational healthcare databases. These findings confirm that it will be important to generate empiric evidence to inform these decisions and to promote a better understanding of the impact of standardization on research implementation.

Rotavirus vaccine effectiveness in low-income settings: An evaluation of the test-negative design.

PubMed

Schwartz, Lauren M; Halloran, M Elizabeth; Rowhani-Rahbar, Ali; Neuzil, Kathleen M; Victor, John C

2017-01-03

The test-negative design (TND), an epidemiologic method currently used to measure rotavirus vaccine (RV) effectiveness, compares the vaccination status of rotavirus-positive cases and rotavirus-negative controls meeting a pre-defined case definition for acute gastroenteritis. Despite the use of this study design in low-income settings, the TND has not been evaluated to measure rotavirus vaccine effectiveness. This study builds upon prior methods to evaluate the use of the TND for influenza vaccine using a randomized controlled clinical trial database. Test-negative vaccine effectiveness (VE-TND) estimates were derived from three large randomized placebo-controlled trials (RCTs) of monovalent (RV1) and pentavalent (RV5) rotavirus vaccines in sub-Saharan Africa and Asia. Derived VE-TND estimates were compared to the original RCT vaccine efficacy estimates (VE-RCTs). The core assumption of the TND (i.e., rotavirus vaccine has no effect on rotavirus-negative diarrhea) was also assessed. TND vaccine effectiveness estimates were nearly equivalent to original RCT vaccine efficacy estimates. Neither RV had a substantial effect on rotavirus-negative diarrhea. This study supports the TND as an appropriate epidemiologic study design to measure rotavirus vaccine effectiveness in low-income settings. Copyright © 2016 The Author(s). Published by Elsevier Ltd.. All rights reserved.

Clinical epidemiology survey of the traditional Chinese medicine etiology and syndrome differentiation of coronary artery disease: study protocol of a multicenter trial.

PubMed

Bi, Ying-fei; Mao, Jing-yuan; Wang, Xian-liang; Hou, Ya-zhu; Lu, Yi-zhu; Soh, Shan Bin; Zhang, Bo-li

2012-06-01

Coronary artery disease (CAD), a common disease with high incidence and mortality rate, has seriously threatened the health and life of the public. Traditional Chinese medicine (TCM) has an important role in the prevention and treatment of this disease. Through clinical epidemiological survey, a deeper understanding of TCM etiology and syndrome characteristics in CAD would further improve clinical efficacy in the treatment of this disease. The preliminary clinical questionnaire for TCM etiology and syndrome differentiation in CAD was designed after literature reviews and analysis. Through a series of clinical pre-surveys, expert consultation and demonstration, the formal TCM clinical epidemiology questionnaire on the etiology and syndrome differentiation in CAD was finalized, after which, the study protocol, inclusive and exclusive criteria and related quality control measures were prepared. The multiregional clinical epidemiological survey with more than 5000 participants with CAD will be carried out in 41 TCM hospitals of China for investigating the TCM etiology and syndrome differentiation of CAD. Multiregion large sample size clinical epidemiology survey on TCM etiology and syndrome differentiation in CAD will provide further evidence in preventing CAD and improving the standardization process of syndrome research. This study protocol was registered at the Chinese Clinical Trial Registry on November 27, 2011 in both Chinese and English editions and the registration number is ChiCTR-ECS-11001728.

Center for Epidemiologic Studies Depression Scale for Children: psychometric testing of the Chinese version.

PubMed

Li, Ho Cheung William; Chung, Oi Kwan Joyce; Ho, Ka Yan

2010-11-01

This paper is a report of psychometric testing of the Chinese version of the Center for Epidemiologic Studies Depression Scale for Children. The availability of a valid and reliable instrument that accurately detects depressive symptoms in children is crucial before any psychological intervention can be appropriately planned and evaluated. There is no such an instrument for Chinese children. A test-retest, within-subjects design was used. A total of 313 primary school students between the ages of 8 and 12 years were invited to participate in the study in 2009. Participants were asked to respond to the Chinese version of the Center for Epidemiologic Studies Depression Scale for Children, short form of the State Anxiety Scale for Children and Rosenberg's Self-Esteem Scale. The internal consistency, content validity and construct validity and test-retest reliability of the Chinese version of the Center for Epidemiologic Studies Depression Scale for Children were assessed. The newly-translated scale demonstrated adequate internal consistency, good content validity and appropriate convergent and discriminant validity. Confirmatory factor analysis added further evidence of the construct validity of the scale. Results suggest that the newly-translated scale can be used as a self-report assessment tool in detecting depressive symptoms of Chinese children aged between 8 and 12 years. © 2010 Blackwell Publishing Ltd.

ESTIMATES OF ENDEMIC WATERBORNE ILLNESS FROM COMMUNITY INTERVENTION STUDIES

EPA Science Inventory

The nature and magnitude of endemic waterborne disease are not well characterized in the

United States. Epidemiologic studies of various designs can provide an estimate of the

waterborne attributable risk along with other types of information. Community drinking wat...

'Next-Generation' Surveillance: An Epidemiologists' Perspective on the Use of Molecular Information in Food Safety and Animal Health Decision-Making.

PubMed

Muellner, P; Stärk, K D C; Dufour, S; Zadoks, R N

2016-08-01

Advances in the availability and affordability of molecular and genomic data are transforming human health care. Surveillance aimed at supporting and improving food safety and animal health is likely to undergo a similar transformation. We propose a definition of 'molecular surveillance' in this context and argue that molecular data are an adjunct to rather than a substitute for sound epidemiological study and surveillance design. Specific considerations with regard to sample collection are raised, as is the importance of the relation between the molecular clock speed of genetic markers and the spatiotemporal scale of the surveillance activity, which can be control- or strategy-focused. Development of standards for study design and assessment of molecular surveillance system attributes is needed, together with development of an interdisciplinary skills base covering both molecular and epidemiological principles. © 2015 Blackwell Verlag GmbH.

Arsenic metabolism and cancer risk: A meta-analysis.

PubMed

Gamboa-Loira, Brenda; Cebrián, Mariano E; Franco-Marina, Francisco; López-Carrillo, Lizbeth

2017-07-01

To describe the studies that have reported association measures between risk of cancer and the percentage distribution of urinary inorganic arsenic (iAs) metabolites by anatomical site, in non-ecological epidemiological studies. Studies were identified in the PubMed database in the period from 1990 to 2015. Inclusion criteria were: non-ecological epidemiological study, with histologically confirmed cancer cases, reporting the percentage distribution of inorganic arsenic (iAs), monomethylated (MMA) and dimethylated (DMA) metabolites, as well as association measures with confidence intervals (CI) between cancer and %iAs and/or %MMA and/or %DMA. A descriptive meta-analysis was performed by the method of the inverse of the variance for the fixed effects model and the DerSimonian and Laird's method for the random effects model. Heterogeneity was tested using the Q statistic and stratifying for epidemiological design and total As in urine. The possibility of publication bias was assessed through Begg's test. A total of 13 eligible studies were found, most of them were performed in Taiwan and focused on skin and bladder cancer. The positive association between %MMA and various types of cancer was consistent, in contrast to the negative relationship between %DMA and cancer that was inconsistent. The summary risk of bladder (OR=1.79; 95% CI: 1.42, 2.26, n=4 studies) and lung (OR=2.44; 95% CI: 1.57, 3.80, n=2 studies) cancer increased significantly with increasing %MMA, without statistical heterogeneity. In contrast, lung cancer risk was inversely related to %DMA (OR=0.58; 95% CI: 0.36, 0.93, n=2 studies), also without significant heterogeneity. These results were similar after stratifying by epidemiological design and total As in urine. No evidence of publication bias was found. These findings provide additional support that methylation needs to be taken into account when assessing the potential iAs carcinogenicity risk. Copyright © 2017. Published by Elsevier Inc.

The Zambia Children's KS-HHV8 Study: Rationale, Study Design, and Study Methods

PubMed Central

Minhas, Veenu; Crabtree, Kay L.; Chao, Ann; Wojcicki, Janet M.; Sifuniso, Adrian M.; Nkonde, Catherine; Kankasa, Chipepo; Mitchell, Charles D.; Wood, Charles

2011-01-01

The epidemic of human immunodeficiency virus in Zambia has led to a dramatic rise in the incidence of human herpesvirus-8 (HHV-8)–associated Kaposi's sarcoma in both adults and children. However, there is a paucity of knowledge about the routes of HHV-8 transmission to young children. The Zambia Children's KS-HHV8 Study, a large, prospective cohort study in Lusaka, Zambia, was launched in 2004 to investigate the role of household members as a source of HHV-8 infection in young children and social behaviors that may modify the risk of HHV-8 acquisition. This cohort is distinct from other epidemiologic studies designed to investigate HHV-8 incidence and transmission because it recruited and followed complete households in the urban central African context. Between July 2004 and March 2007, 1,600 households were screened; 368 households comprising 464 children and 1,335 caregivers and household members were enrolled. Follow-up of this population continued for 48 months postrecruitment, affording a unique opportunity to study horizontal transmission of HHV-8 and understand the routes and sources of transmission to young children in Zambia. The authors describe the study rationale, design, execution, and characteristics of this cohort, which provides critical data on the epidemiology and transmission of HHV-8 to young children in Zambia. PMID:21447476

Is protective equipment useful in preventing concussion? A systematic review of the literature.

PubMed

Benson, B W; Hamilton, G M; Meeuwisse, W H; McCrory, P; Dvorak, J

2009-05-01

To determine if there is evidence that equipment use reduces sport concussion risk and/or severity. 12 electronic databases were searched using a combination of Medical Subject Headings and text words to identify relevant articles. Specific inclusion and exclusion criteria were used to select studies for review. Data extracted included design, study population, exposure/outcome measures and results. The quality of evidence was assessed based on epidemiologic criteria regarding internal and external validity (ie, strength of design, sample size/power calculation, selection bias, misclassification bias, control of potential confounding and effect modification). In total, 51 studies were selected for review. A comparison between studies was difficult due to the variability in research designs, definition of concussion, mouthguard/helmet/headgear/face shield types, measurements used to assess exposure and outcomes, and variety of sports assessed. The majority of studies were observational, with 23 analytical epidemiologic designs related to the subject area. Selection bias was a concern in the reviewed studies, as was the lack of measurement and control for potentially confounding variables. There is evidence that helmet use reduces head injury risk in skiing, snowboarding and bicycling, but the effect on concussion risk is inconclusive. No strong evidence exists for the use of mouthguards or face shields to reduce concussion risk. Evidence is provided to suggest that full facial protection in ice hockey may reduce concussion severity, as measured by time loss from competition.

A Systematic Review of the Epidemiology of Echinococcosis in Domestic and Wild Animals

PubMed Central

Otero-Abad, Belen; Torgerson, Paul R.

2013-01-01

Background Human echinococcosis is a neglected zoonosis caused by parasites of the genus Echinococcus. The most frequent clinical forms of echinococcosis, cystic echinococcosis (CE) and alveolar echinococcosis (AE), are responsible for a substantial health and economic burden, particularly to low-income societies. Quantitative epidemiology can provide important information to improve the understanding of parasite transmission and hence is an important part of efforts to control this disease. The purpose of this review is to give an insight on factors associated with echinococcosis in animal hosts by summarising significant results reported from epidemiological studies identified through a systematic search. Methodology and Principal Findings The systematic search was conducted mainly in electronic databases but a few additional records were obtained from other sources. Retrieved entries were examined in order to identify available peer-reviewed epidemiological studies that found significant risk factors for infection using associative statistical methods. One hundred studies met the eligibility criteria and were suitable for data extraction. Epidemiological factors associated with increased risk of E. granulosus infection in dogs included feeding with raw viscera, possibility of scavenging dead animals, lack of anthelmintic treatment and owners' poor health education and indicators of poverty. Key factors associated with E. granulosus infection in intermediate hosts were related to the hosts' age and the intensity of environmental contamination with parasite eggs. E. multilocularis transmission dynamics in animal hosts depended on the interaction of several ecological factors, such as hosts' population densities, host-prey interactions, landscape characteristics, climate conditions and human-related activities. Conclusions/Significance Results derived from epidemiological studies provide a better understanding of the behavioural, biological and ecological factors involved in the transmission of this parasite and hence can aid in the design of more effective control strategies. PMID:23755310

Neisseria gonorrhoeae molecular typing for understanding sexual networks and antimicrobial resistance transmission: A systematic review.

PubMed

Town, Katy; Bolt, Hikaru; Croxford, Sara; Cole, Michelle; Harris, Simon; Field, Nigel; Hughes, Gwenda

2018-06-01

Neisseria gonorrhoeae (NG) is a significant global public health concern due to rising diagnoses rates and antimicrobial resistance. Molecular combined with epidemiological data have been used to understand the distribution and spread of NG, as well as relationships between cases in sexual networks, but the public health value gained from these studies is unclear. We conducted a systematic review to examine how molecular epidemiological studies have informed understanding of sexual networks and NG transmission, and subsequent public health interventions. Five research databases were systematically searched up to 31st March 2017 for studies that used sequence-based DNA typing methods, including whole genome sequencing, and linked molecular data to patient-level epidemiological data. Data were extracted and summarised to identify common themes. Of the 49 studies included, 82% used NG Multi-antigen Sequence Typing. Gender and sexual orientation were commonly used to characterise sexual networks that were inferred using molecular clusters; clusters predominantly of one patient group often contained a small number of isolates from other patient groups. Suggested public health applications included using these data to target interventions at specific populations, confirm outbreaks, and inform partner management, but these were mainly untested. Combining molecular and epidemiological data has provided insight into sexual mixing patterns, and dissemination of NG, but few studies have applied these findings to design or evaluate public health interventions. Future studies should focus on the application of molecular epidemiology in public health practice to provide evidence for how to prevent and control NG. Copyright © 2018 The Authors. Published by Elsevier Ltd.. All rights reserved.

THE LONG ISLAND BREAST CANCER STUDY (LIBCSP)

EPA Science Inventory

The NIEHS and the NCI are collaborating on the Long Island Breast Cancer Study Project (LIBCSP), which is designed to conduct epidemiologic research on the role of environmental factors in the etiology of breast cancer in women who live in Nassau and Suffolk counties, New York. T...

Epidemiological study of acute poisoning in children: a 5-year retrospective study in the Paediatric University Hospital in Białystok, Poland.

PubMed

Pawłowicz, Urszula; Wasilewska, Anna; Olański, Witold; Stefanowicz, Marta

2013-09-01

Poisoning among children and youths in the northeastern part of Poland accounted for 25% of the total number of patients admitted to the Hospital Emergency Department of the Paediatric University Hospital of Białystok. We hypothesise that the epidemiology of poisoned paediatric patients admitted is related to increase in 'designer drugs' (mainly amphetamine- and ecstasy-like psychostimulants, hallucinogens and synthetic cannabinoids ('spice') intake, which became popular 5 years ago in our country. A retrospective chart review of medical records of 489 patients admitted due to poisoning in the 5-year period (2006-2010). The data included: age, sex, place of residence, nature of the substance, causes of poisoning, former use of psychoactive stimulants, accompanying self-mutilation and injuries and length of hospitalisation. Categorical variables were expressed as percentages, and continuous variables as mean and SD. The data were collected in a Microsoft Excel database. Statistical analysis was performed using the Statistical Programme for Social Sciences. Out of 2176 hospitalised children, 489 were admitted because of poisoning. Out of these, 244 (49.9%) were hospitalised due to intoxication by alcohol. Only eight children used designer drugs. The mean age of all patients in our group was 12.86±5.04 years, of which 52.4% were male. Poisoning was intentional in 75.5%, and accidental in 24.5% of cases. Appearance of 'designer drugs' had no significant impact on the number and epidemiology of poisonings in our group.

Integrating Epidemiology, Education, and Organizing for Environmental Justice: Community Health Effects of Industrial Hog Operations

PubMed Central

Wing, Steve; Horton, Rachel Avery; Muhammad, Naeema; Grant, Gary R.; Tajik, Mansoureh; Thu, Kendall

2008-01-01

The environmental justice movement has stimulated community-driven research about the living and working conditions of people of color and low-income communities. We describe an epidemiological study designed to link research with community education and organizing for social justice. In eastern North Carolina, high-density industrial swine production occurs in communities of low-income people and people of color. We investigated relationships between the resulting pollution and the health and quality of life of the hog operations’ neighbors. A repeat-measures longitudinal design, community involvement in data collection, and integration of qualitative and quantitative research methods helped promote data quality while providing opportunities for community education and organizing. Research could affect policy through its findings and its mobilization of communities. PMID:18556620

The utility of web mining for epidemiological research: studying the association between parity and cancer risk [Web Mining for Epidemiological Research. Assessing its Utility in Exploring the Association Between Parity and Cancer Risk

DOE PAGES

Tourassi, Georgia; Yoon, Hong-Jun; Xu, Songhua; ...

2015-11-27

Background: The World Wide Web has emerged as a powerful data source for epidemiological studies related to infectious disease surveillance. However, its potential for cancer-related epidemiological discoveries is largely unexplored. Methods: Using advanced web crawling and tailored information extraction procedures we automatically collected and analyzed the text content of 79,394 online obituary articles published between 1998 and 2014. The collected data included 51,911 cancer (27,330 breast; 9,470 lung; 6,496 pancreatic; 6,342 ovarian; 2,273 colon) and 27,483 non-cancer cases. With the derived information, we replicated a case-control study design to investigate the association between parity and cancer risk. Age-adjusted odds ratiosmore » (ORs) with 95% confidence intervals (CIs) were calculated for each cancer type and compared to those reported in large-scale epidemiological studies. Results: Parity was found to be associated with a significantly reduced risk of breast cancer (OR=0.78, 95% CI = 0.75 to 0.82), pancreatic cancer (OR=0.78, 95% CI = 0.72 to 0.83), colon cancer (OR=0.67, 95% CI = 0.60 to 0.74), and ovarian cancer (OR=0.58, 95% CI = 0.54 to 0.62). Marginal association was found for lung cancer prevalence (OR=0.87, 95% CI = 0.81 to 0.92). The linear trend between multi-parity and reduced cancer risk was dramatically more pronounced for breast and ovarian cancer than the other cancers included in the analysis. Conclusion: This large web-mining study on parity and cancer risk produced findings very similar to those reported with traditional observational studies. It may be used as a promising strategy to generate study hypotheses for guiding and prioritizing future epidemiological studies.« less

The utility of web mining for epidemiological research: studying the association between parity and cancer risk [Web Mining for Epidemiological Research. Assessing its Utility in Exploring the Association Between Parity and Cancer Risk

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tourassi, Georgia; Yoon, Hong-Jun; Xu, Songhua

Background: The World Wide Web has emerged as a powerful data source for epidemiological studies related to infectious disease surveillance. However, its potential for cancer-related epidemiological discoveries is largely unexplored. Methods: Using advanced web crawling and tailored information extraction procedures we automatically collected and analyzed the text content of 79,394 online obituary articles published between 1998 and 2014. The collected data included 51,911 cancer (27,330 breast; 9,470 lung; 6,496 pancreatic; 6,342 ovarian; 2,273 colon) and 27,483 non-cancer cases. With the derived information, we replicated a case-control study design to investigate the association between parity and cancer risk. Age-adjusted odds ratiosmore » (ORs) with 95% confidence intervals (CIs) were calculated for each cancer type and compared to those reported in large-scale epidemiological studies. Results: Parity was found to be associated with a significantly reduced risk of breast cancer (OR=0.78, 95% CI = 0.75 to 0.82), pancreatic cancer (OR=0.78, 95% CI = 0.72 to 0.83), colon cancer (OR=0.67, 95% CI = 0.60 to 0.74), and ovarian cancer (OR=0.58, 95% CI = 0.54 to 0.62). Marginal association was found for lung cancer prevalence (OR=0.87, 95% CI = 0.81 to 0.92). The linear trend between multi-parity and reduced cancer risk was dramatically more pronounced for breast and ovarian cancer than the other cancers included in the analysis. Conclusion: This large web-mining study on parity and cancer risk produced findings very similar to those reported with traditional observational studies. It may be used as a promising strategy to generate study hypotheses for guiding and prioritizing future epidemiological studies.« less

Evolution and social epidemiology.

PubMed

Nishi, Akihiro

2015-11-01

Evolutionary biology, which aims to explain the dynamic process of shaping the diversity of life, has not yet significantly affected thinking in social epidemiology. Current challenges in social epidemiology include understanding how social exposures can affect our biology, explaining the dynamics of society and health, and designing better interventions that are mindful of the impact of exposures during critical periods. I review how evolutionary concepts and tools, such as fitness gradient in cultural evolution, evolutionary game theory, and contemporary evolution in cancer, can provide helpful insights regarding social epidemiology. Copyright © 2015 Elsevier Ltd. All rights reserved.

Analysis of Clinical Cohort Data Using Nested Case-control and Case-cohort Sampling Designs. A Powerful and Economical Tool.

PubMed

Ohneberg, K; Wolkewitz, M; Beyersmann, J; Palomar-Martinez, M; Olaechea-Astigarraga, P; Alvarez-Lerma, F; Schumacher, M

2015-01-01

Sampling from a large cohort in order to derive a subsample that would be sufficient for statistical analysis is a frequently used method for handling large data sets in epidemiological studies with limited resources for exposure measurement. For clinical studies however, when interest is in the influence of a potential risk factor, cohort studies are often the first choice with all individuals entering the analysis. Our aim is to close the gap between epidemiological and clinical studies with respect to design and power considerations. Schoenfeld's formula for the number of events required for a Cox' proportional hazards model is fundamental. Our objective is to compare the power of analyzing the full cohort and the power of a nested case-control and a case-cohort design. We compare formulas for power for sampling designs and cohort studies. In our data example we simultaneously apply a nested case-control design with a varying number of controls matched to each case, a case cohort design with varying subcohort size, a random subsample and a full cohort analysis. For each design we calculate the standard error for estimated regression coefficients and the mean number of distinct persons, for whom covariate information is required. The formula for the power of a nested case-control design and the power of a case-cohort design is directly connected to the power of a cohort study using the well known Schoenfeld formula. The loss in precision of parameter estimates is relatively small compared to the saving in resources. Nested case-control and case-cohort studies, but not random subsamples yield an attractive alternative for analyzing clinical studies in the situation of a low event rate. Power calculations can be conducted straightforwardly to quantify the loss of power compared to the savings in the num-ber of patients using a sampling design instead of analyzing the full cohort.

Phylogenetic studies of transmission dynamics in generalized HIV epidemics: An essential tool where the burden is greatest?

PubMed Central

Dennis, Ann M.; Herbeck, Joshua T.; Brown, Andrew Leigh; Kellam, Paul; de Oliveira, Tulio; Pillay, Deenan; Fraser, Christophe; Cohen, Myron S.

2014-01-01

Efficient and effective HIV prevention measures for generalized epidemics in sub-Saharan Africa have not yet been validated at the population-level. Design and impact evaluation of such measures requires fine-scale understanding of local HIV transmission dynamics. The novel tools of HIV phylogenetics and molecular epidemiology may elucidate these transmission dynamics. Such methods have been incorporated into studies of concentrated HIV epidemics to identify proximate and determinant traits associated with ongoing transmission. However, applying similar phylogenetic analyses to generalized epidemics, including the design and evaluation of prevention trials, presents additional challenges. Here we review the scope of these methods and present examples of their use in concentrated epidemics in the context of prevention. Next, we describe the current uses for phylogenetics in generalized epidemics, and discuss their promise for elucidating transmission patterns and informing prevention trials. Finally, we review logistic and technical challenges inherent to large-scale molecular epidemiological studies of generalized epidemics, and suggest potential solutions. PMID:24977473

An Interactive, Web-based High Performance Modeling Environment for Computational Epidemiology.

PubMed

Deodhar, Suruchi; Bisset, Keith R; Chen, Jiangzhuo; Ma, Yifei; Marathe, Madhav V

2014-07-01

We present an integrated interactive modeling environment to support public health epidemiology. The environment combines a high resolution individual-based model with a user-friendly web-based interface that allows analysts to access the models and the analytics back-end remotely from a desktop or a mobile device. The environment is based on a loosely-coupled service-oriented-architecture that allows analysts to explore various counter factual scenarios. As the modeling tools for public health epidemiology are getting more sophisticated, it is becoming increasingly hard for non-computational scientists to effectively use the systems that incorporate such models. Thus an important design consideration for an integrated modeling environment is to improve ease of use such that experimental simulations can be driven by the users. This is achieved by designing intuitive and user-friendly interfaces that allow users to design and analyze a computational experiment and steer the experiment based on the state of the system. A key feature of a system that supports this design goal is the ability to start, stop, pause and roll-back the disease propagation and intervention application process interactively. An analyst can access the state of the system at any point in time and formulate dynamic interventions based on additional information obtained through state assessment. In addition, the environment provides automated services for experiment set-up and management, thus reducing the overall time for conducting end-to-end experimental studies. We illustrate the applicability of the system by describing computational experiments based on realistic pandemic planning scenarios. The experiments are designed to demonstrate the system's capability and enhanced user productivity.

An Interactive, Web-based High Performance Modeling Environment for Computational Epidemiology

PubMed Central

Deodhar, Suruchi; Bisset, Keith R.; Chen, Jiangzhuo; Ma, Yifei; Marathe, Madhav V.

2014-01-01

We present an integrated interactive modeling environment to support public health epidemiology. The environment combines a high resolution individual-based model with a user-friendly web-based interface that allows analysts to access the models and the analytics back-end remotely from a desktop or a mobile device. The environment is based on a loosely-coupled service-oriented-architecture that allows analysts to explore various counter factual scenarios. As the modeling tools for public health epidemiology are getting more sophisticated, it is becoming increasingly hard for non-computational scientists to effectively use the systems that incorporate such models. Thus an important design consideration for an integrated modeling environment is to improve ease of use such that experimental simulations can be driven by the users. This is achieved by designing intuitive and user-friendly interfaces that allow users to design and analyze a computational experiment and steer the experiment based on the state of the system. A key feature of a system that supports this design goal is the ability to start, stop, pause and roll-back the disease propagation and intervention application process interactively. An analyst can access the state of the system at any point in time and formulate dynamic interventions based on additional information obtained through state assessment. In addition, the environment provides automated services for experiment set-up and management, thus reducing the overall time for conducting end-to-end experimental studies. We illustrate the applicability of the system by describing computational experiments based on realistic pandemic planning scenarios. The experiments are designed to demonstrate the system's capability and enhanced user productivity. PMID:25530914

Air Quality Modeling in Support of the Near-road EXposures and effects of Urban air pollutants Study (NEXUS)

EPA Science Inventory

The paper presents the results of the model applications to estimate exposure metrics in support of an epidemiologic study in Detroit, Michigan. The Near-road Exposures to Urban air pollutant Study (NEXUS) design includes determining if children in Detroit, MI with asthma living ...

Risk factors associated with asbestos-related diseases: a community-based case-control study.

PubMed

Rosell-Murphy, Magdalena-Isabel; Abós-Herràndiz, Rafael; Olivella, Josep Tarrés; Alberti-Casas, Constança; Allas, Isabel García; Artés, Xavier Martinez; Günther, Ilona Krier; Malet, Isidre Grimau; Martínez, Ramon Orriols; Canela-Soler, Jaume

2013-08-06

Asbestos is a first level carcinogen. However, few epidemiological studies analyse the risk and protective factors associated with asbestos-related diseases and follow up these conditions in the general population. Pleural mesothelioma, caused by inhalation of asbestos fibres at work, at home or in the environment, is the most representative asbestos-related disease.The objectives of this study are to analyse the risk and protective factors associated with asbestos-related diseases and to investigate the incidence of new clinical manifestations in patients already diagnosed with some form of ARD. We have designed a matched case-control study with follow up of both cohorts from a population of a health district of the Barcelona province that has been exposed to asbestos for a period of 90 years. A better understanding of asbestos-related diseases should improve i) the clinical and epidemiological follow up of patients with this condition; ii) the design of new treatment strategies; iii) and the development of preventive activities. At the end of the study, the two cohorts created in this study (affected cases and healthy controls) will constitute the basis for future research.

The utility of web mining for epidemiological research: studying the association between parity and cancer risk

PubMed Central

Yoon, Hong-Jun; Xu, Songhua; Han, Xuesong

2016-01-01

Background The World Wide Web has emerged as a powerful data source for epidemiological studies related to infectious disease surveillance. However, its potential for cancer-related epidemiological discoveries is largely unexplored. Methods Using advanced web crawling and tailored information extraction procedures, the authors automatically collected and analyzed the text content of 79 394 online obituary articles published between 1998 and 2014. The collected data included 51 911 cancer (27 330 breast; 9470 lung; 6496 pancreatic; 6342 ovarian; 2273 colon) and 27 483 non-cancer cases. With the derived information, the authors replicated a case-control study design to investigate the association between parity (i.e., childbearing) and cancer risk. Age-adjusted odds ratios (ORs) with 95% confidence intervals (CIs) were calculated for each cancer type and compared to those reported in large-scale epidemiological studies. Results Parity was found to be associated with a significantly reduced risk of breast cancer (OR = 0.78, 95% CI, 0.75-0.82), pancreatic cancer (OR = 0.78, 95% CI, 0.72-0.83), colon cancer (OR = 0.67, 95% CI, 0.60-0.74), and ovarian cancer (OR = 0.58, 95% CI, 0.54-0.62). Marginal association was found for lung cancer risk (OR = 0.87, 95% CI, 0.81-0.92). The linear trend between increased parity and reduced cancer risk was dramatically more pronounced for breast and ovarian cancer than the other cancers included in the analysis. Conclusion This large web-mining study on parity and cancer risk produced findings very similar to those reported with traditional observational studies. It may be used as a promising strategy to generate study hypotheses for guiding and prioritizing future epidemiological studies. PMID:26615183

Using Accelerometers to Measure Physical Activity in Large-Scale Epidemiologic Studies: Issues and Challenges

PubMed Central

Lee, I-Min; Shiroma, Eric J

2013-01-01

Background Current guidelines for aerobic activity require that adults carry out ≥150 minutes/week of moderate-intensity physical activity, with a large body of epidemiologic evidence showing this level of activity to decrease the incidence of many chronic diseases. Less is known about whether light-intensity activities also have such benefits, and whether sedentary behavior is an independent predictor of increased risks of these chronic diseases, as imprecise assessments of these behaviours and cross-sectional study designs have limited knowledge to date. Methods Recent technological advances in assessment methods have made the use of movement sensors, such as the accelerometer, feasible for use in longitudinal, large-scale epidemiologic studies. Several such studies are collecting sensor-assessed, objective measures of physical activity with the aim of relating these to the development of clinical endpoints. This is a relatively new area of research; thus, in this paper, we use the Women’s Health Study (WHS) as a case study to illustrate challenges related to data collection, data processing, and analyses of the vast amount of data collected. Results The WHS plans to collect 7 days of accelerometer-assessed physical activity and sedentary behavior in ~18,000 women aged ≥62 years. Several logistical challenges exist in collecting data; nonetheless as of 31 August 2013, 11,590 women have already provided some data. Additionally, the WHS experience on data reduction and data analyses can help inform other similar large-scale epidemiologic studies. Conclusions Important data on the health effects of light-intensity activity and sedentary behaviour will emerge from large-scale epidemiologic studies collecting objective assessments of these behaviours. PMID:24297837

Cardiovascular Effects Caused by Increasing Concentrations of Diesel Exhaust in Middle-Aged Healthy GSTM1 Null Human Volunteers

EPA Science Inventory

ABSTRACT Objectives: Epidemiological studies have shown an association between the incidence of adverse cardiovascular effects and exposure to ambient particulate matter (PM). Diesel exhaust (DE) is a major contributor to ambient PM in urban areas. This study was designed to e...

IDENTIFICATION OF POSSIBLE SOURCES OF PARTICULATE MATTER IN THE PERSONAL CLOUD USING SEM/EDX

EPA Science Inventory

The United States Environmental Protection Agency (U.S. EPA) conducted the Baltimore Particulate Matter (PM) Epidemiology-Exposure Study of the Elderly during the summer of 1998. The study design included PM2.5 samples obtained from elderly (65+ years of age) retirement facility ...

Fathers Matter: Why It’s Time to Consider the Impact of Paternal Environmental Exposures on Children’s Health

PubMed Central

Braun, Joseph M.; Messerlian, Carmen; Hauser, Russ

2017-01-01

Purpose Despite accumulating evidence from experimental animal studies showing that paternal environmental exposures induce genetic and epigenetic alterations in sperm which in turn increase the risk of adverse health outcomes in offspring, there is limited epidemiological data on the effects of human paternal preconception exposures on children’s health. We summarize animal and human studies showing that paternal preconception environmental exposures influence offspring health. We discuss specific approaches and designs for human studies to investigate the health effects of paternal preconception exposures, the specific challenges these studies may face, and how we might address them. Recent Findings In animal studies, paternal preconception diet, stress, and chemical exposures have been associated with offspring health and these effects are mediated by epigenetic modifications transmitted through sperm DNA, histones, and RNA. Most epidemiological studies have examined paternal preconception occupational exposures and their effect on the risk of birth defects and childhood cancer; few have examined the effects of low-level general population exposure to environmental toxicants. While the design and execution of epidemiological studies of paternal preconception exposures face challenges, particularly with regard to selection bias and recruitment, we believe these are tractable and that preconception studies are feasible. Summary New or augmented prospective cohort studies would be the optimal method to address the critical knowledge gaps on the effect of paternal preconception exposures on prevalent childhood health outcomes. Determining if this period of life represents a window of heightened vulnerability would improve our understanding of modifiable risk factors for children’s health and wellbeing. PMID:28848695

Use of benzodiazepine and risk of cancer: A meta-analysis of observational studies.

PubMed

Kim, Hong-Bae; Myung, Seung-Kwon; Park, Yon Chul; Park, Byoungjin

2017-02-01

Several observational epidemiological studies have reported inconsistent results on the association between the use of benzodiazepine and the risk of cancer. We investigated the association by using a meta-analysis. We searched PubMed, EMBASE, and the bibliographies of relevant articles to locate additional publications in January 2016. Three evaluators independently reviewed and selected eligible studies based on predetermined selection criteria. Of 796 articles meeting our initial criteria, a total of 22 observational epidemiological studies with 18 case-control studies and 4 cohort studies were included in the final analysis. Benzodiazepine use was significantly associated with an increased risk of cancer (odds ratio [OR] or relative risk [RR] 1.19; 95% confidence interval 1.16-1.21) in a random-effects meta-analysis of all studies. Subgroup meta-analyses by various factors such as study design, type of case-control study, study region, and methodological quality of study showed consistent findings. Also, a significant dose-response relationship was observed between the use of benzodiazepine and the risk of cancer (p for trend <0.01). The current meta-analysis of observational epidemiological studies suggests that benzodiazepine use is associated with an increased risk of cancer. © 2016 UICC.

Chromium and disease: review of epidemiologic studies with particular reference to etiologic information provided by measures of exposure.

PubMed Central

Lees, P S

1991-01-01

Dozens of epidemiologic studies have been conducted since the late 1940s in an attempt to elucidate the relationship between exposure to chromium compounds and increased rates of certain cancers observed in several industries. The relationship between employment in industries producing chromium compounds from chromite ore and lung cancer has been well established in numerous studies. The relationship between exposure to certain chromium-based pigments and chromic acid and lung cancer, although not as strong, is fairly well accepted. The data concerning emissions from stainless-steel manufacturing and disease are contradictory. Although individual studies have indicated excesses of gastrointestinal and occasionally other cancers in these industries, results are not consistent and not universally accepted. There is general agreement that chromite ore does not have an associated risk of cancer. Although the chromium compound (or compounds) responsible for disease have yet to be identified, there is general agreement that hexavalent species are responsible for these diseases and that the trivalent species are not. Hypotheses about the carcinogenicity of specific chromium compounds generally relate to their solubility in body fluids. These hypotheses, however, have generally been produced as a result of toxicologic, not epidemiologic, investigation. Well-designed epidemiologic studies incorporating detailed assessments of worker exposures have the potential to help elucidate causality, identify specific carcinogenic compounds, and quantify risk in humans, eliminating the need to extrapolate from animal data. Although the need for exposure data crucial to this effort was identified in the earliest epidemiologic studies of chromium, such studies have not been conducted. As a result, little more is known today about the relationship between this chemical and disease in humans than was known 40 years ago. PMID:1935857

Computational Evolutionary Methodology for Knowledge Discovery and Forecasting in Epidemiology and Medicine

NASA Astrophysics Data System (ADS)

Rao, Dhananjai M.; Chernyakhovsky, Alexander; Rao, Victoria

2008-05-01

Humanity is facing an increasing number of highly virulent and communicable diseases such as avian influenza. Researchers believe that avian influenza has potential to evolve into one of the deadliest pandemics. Combating these diseases requires in-depth knowledge of their epidemiology. An effective methodology for discovering epidemiological knowledge is to utilize a descriptive, evolutionary, ecological model and use bio-simulations to study and analyze it. These types of bio-simulations fall under the category of computational evolutionary methods because the individual entities participating in the simulation are permitted to evolve in a natural manner by reacting to changes in the simulated ecosystem. This work describes the application of the aforementioned methodology to discover epidemiological knowledge about avian influenza using a novel eco-modeling and bio-simulation environment called SEARUMS. The mathematical principles underlying SEARUMS, its design, and the procedure for using SEARUMS are discussed. The bio-simulations and multi-faceted case studies conducted using SEARUMS elucidate its ability to pinpoint timelines, epicenters, and socio-economic impacts of avian influenza. This knowledge is invaluable for proactive deployment of countermeasures in order to minimize negative socioeconomic impacts, combat the disease, and avert a pandemic.

Computational Evolutionary Methodology for Knowledge Discovery and Forecasting in Epidemiology and Medicine

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rao, Dhananjai M.; Chernyakhovsky, Alexander; Rao, Victoria

2008-05-08

Humanity is facing an increasing number of highly virulent and communicable diseases such as avian influenza. Researchers believe that avian influenza has potential to evolve into one of the deadliest pandemics. Combating these diseases requires in-depth knowledge of their epidemiology. An effective methodology for discovering epidemiological knowledge is to utilize a descriptive, evolutionary, ecological model and use bio-simulations to study and analyze it. These types of bio-simulations fall under the category of computational evolutionary methods because the individual entities participating in the simulation are permitted to evolve in a natural manner by reacting to changes in the simulated ecosystem. Thismore » work describes the application of the aforementioned methodology to discover epidemiological knowledge about avian influenza using a novel eco-modeling and bio-simulation environment called SEARUMS. The mathematical principles underlying SEARUMS, its design, and the procedure for using SEARUMS are discussed. The bio-simulations and multi-faceted case studies conducted using SEARUMS elucidate its ability to pinpoint timelines, epicenters, and socio-economic impacts of avian influenza. This knowledge is invaluable for proactive deployment of countermeasures in order to minimize negative socioeconomic impacts, combat the disease, and avert a pandemic.« less

Invited Commentary: Cassel's "The Contribution of the Social Environment to Host Resistance"-A Modern Classic.

PubMed

James, Sherman A

2017-06-01

John Cassel's 1976 paper "The Contribution of the Social Environment to Host Resistance" (Am J Epidemiol. 1976;104(2):107-123) is widely regarded as a classic in epidemiology. He makes the compelling argument that the quality of a person's social relationships, that is, the degree to which her relationships are more stressful than supportive (or vice versa) influences her susceptibility to disease independent of genetic endowment, diet, physical activity, etc. Cassel's provocative thesis was anchored in a cogent synthesis of findings from animal experiments and observational studies on diverse human populations. Beginning in the late 1970s, the paper stimulated an explosion of epidemiologic research on social support and human health. Beyond advancing epidemiologic theory, Cassel showed how findings from various epidemiologic study designs could be marshalled to build a persuasive causal argument that impaired social bonds increase the risk of premature disease and death. The paper also foreshadowed core ideas of later theoretical constructs, such as weathering and allostatic load, regarding the power of chronic environmental stressors to accelerate biological aging across multiple organ systems. Cassel's assessment of the research and practice implications of his conclusions has remarkable contemporary resonance for the field of epidemiology. © The Author 2017. Published by Oxford University Press on behalf of the Johns Hopkins Bloomberg School of Public Health. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

A review of the epidemiological methods used to investigate the health impacts of air pollution around major industrial areas.

PubMed

Pascal, Mathilde; Pascal, Laurence; Bidondo, Marie-Laure; Cochet, Amandine; Sarter, Hélène; Stempfelet, Morgane; Wagner, Vérène

2013-01-01

We performed a literature review to investigate how epidemiological studies have been used to assess the health consequences of living in the vicinity of industries. 77 papers on the chronic effects of air pollution around major industrial areas were reviewed. Major health themes were cancers (27 studies), morbidity (25 studies), mortality (7 studies), and birth outcome (7 studies). Only 3 studies investigated mental health. While studies were available from many different countries, a majority of papers came from the United Kingdom, Italy, and Spain. Several studies were motivated by concerns from the population or by previous observations of an overincidence of cases. Geographical ecological designs were largely used for studying cancer and mortality, including statistical designs to quantify a relationship between health indicators and exposure. Morbidity was frequently investigated through cross-sectional surveys on the respiratory health of children. Few multicenter studies were performed. In a majority of papers, exposed areas were defined based on the distance to the industry and were located from <2 km to >20 km from the plants. Improving the exposure assessment would be an asset to future studies. Criteria to include industries in multicenter studies should be defined.

Intricacies of assessing the human microbiome in epidemiological studies

PubMed Central

Robinson, Courtney K.; Brotman, Rebecca M.; Ravel, Jacques

2016-01-01

Purpose In the past decade, remarkable relationships have been documented between dysbiosis of the human microbiota and adverse health outcomes. This review seeks to highlight some of the challenges and pitfalls that may be encountered during all stages of microbiota research, from study design and sample collection, to nucleic acid extraction and sequencing, and bioinformatic and statistical analysis. Methods Literature focused on human microbiota research was reviewed and summarized. Results While most studies have focused on surveying the composition of the microbiota, fewer have explored the causal roles of these bacteria, archaea, viruses, and fungi in affecting disease states. Microbiome research is in its relatively early years and many aspects remain challenging, including the complexity and personalized aspects of microbial communities, the influence of exogenous and often confounding factors, the need to apply fundamental principles of ecology and epidemiology, the necessity for new software tools, and the rapidly evolving genomic, technological, and analytical landscapes. Conclusions Incorporating human microbiome research in large epidemiological studies will soon help us unravel the intricate relationships that we have with our microbial partners and provide interventional opportunities to improve human health. PMID:27180112

Ethical issues in human genome epidemiology: a case study based on the Japanese American Family Study in Seattle, Washington.

PubMed

Austin, Melissa A

2002-04-01

Recent completion of the draft sequence of the human genome has been greeted with both excitement and skepticism, and the potential of this accomplishment for advancing public health has been tempered by ethical concerns about the protection of human subjects. This commentary explores ethical issues arising in human genome epidemiology by using a case study approach based on the ongoing Japanese American Family Study at the University of Washington in Seattle (1994-2003). Ethical issues encountered in designing the study, collecting the data, and reporting the study results are considered. When developing studies, investigators must consider whether to restrict the study to specific racial or ethnic groups and whether community involvement is appropriate. Once the study design is in place, further ethical issues emerge, including obtaining informed consent for DNA banking and protecting the privacy and confidentiality of family members. Finally, investigators must carefully consider whether to report genotype results to study participants and whether pedigrees illustrating the results of the study will be published. Overall, the promise of genomics for improving public health must be pursued based on the fundamental ethical principles of respect for persons, beneficence, and justice.

USE OF EMERGENCY ROOM PATIENT POPULATIONS IN AIR POLLUTION EPIDEMIOLOGY

EPA Science Inventory

The long-term objective of this project was the design and implementation of a particular epidemiological approach to investigation of ambient pollutant effects: the correlation of pollutant exposure with patterns of hospital emergency room utilization. The report covers the init...

The Biomarkers of Exposure and Effect in Agriculture (BEEA) Study: Rationale, design, methods, and participant characteristics

EPA Science Inventory

Agricultural exposures including pesticides, endotoxin, and allergens have been associated with risk of various cancers and other chronic diseases, although the biological mechanisms underlying these associations are generally unclear. To facilitate future molecular epidemiologic...

Defining Dose across Different Experimental Designs: Fiber Equivalent Diameter and Surface Area

EPA Science Inventory

Inhaled fibers (elongated bio-durable particles) of all lengths have been shown to induce pathological responses, but different sizes are respirable in different species. To be able to accurately assess the health effects observed in toxicological or epidemiological studies,...

Design and application of a web-based real-time personal PM2.5 exposure monitoring system.

PubMed

Sun, Qinghua; Zhuang, Jia; Du, Yanjun; Xu, Dandan; Li, Tiantian

2018-06-15

Growing demand from public health research for conduct large-scale epidemiological studies to explore health effect of PM 2.5 was well-documented. To address this need, we design a web-based real-time personal PM 2.5 exposure monitoring system (RPPM2.5 system) which can help researcher to get big data of personal PM 2.5 exposure with low-cost, low labor requirement, and low operating technical requirements. RPPM2.5 system can provide relative accurate real-time personal exposure data for individuals, researches, and decision maker. And this system has been used in a survey of PM 2.5 personal exposure level conducted in 5 cities of China and has provided mass of valuable data for epidemiological research. Copyright © 2018 Elsevier B.V. All rights reserved.

Research designs and making causal inferences from health care studies.

PubMed

Flannelly, Kevin J; Jankowski, Katherine R B

2014-01-01

This article summarizes the major types of research designs used in healthcare research, including experimental, quasi-experimental, and observational studies. Observational studies are divided into survey studies (descriptive and correlational studies), case-studies and analytic studies, the last of which are commonly used in epidemiology: case-control, retrospective cohort, and prospective cohort studies. Similarities and differences among the research designs are described and the relative strength of evidence they provide is discussed. Emphasis is placed on five criteria for drawing causal inferences that are derived from the writings of the philosopher John Stuart Mill, especially his methods or canons. The application of the criteria to experimentation is explained. Particular attention is given to the degree to which different designs meet the five criteria for making causal inferences. Examples of specific studies that have used various designs in chaplaincy research are provided.

Ophthalmic epidemiology in Europe: the "European Eye Epidemiology" (E3) consortium.

PubMed

Delcourt, Cécile; Korobelnik, Jean-François; Buitendijk, Gabriëlle H S; Foster, Paul J; Hammond, Christopher J; Piermarocchi, Stefano; Peto, Tunde; Jansonius, Nomdo; Mirshahi, Alireza; Hogg, Ruth E; Bretillon, Lionel; Topouzis, Fotis; Deak, Gabor; Grauslund, Jakob; Broe, Rebecca; Souied, Eric H; Creuzot-Garcher, Catherine; Sahel, José; Daien, Vincent; Lehtimäki, Terho; Hense, Hans-Werner; Prokofyeva, Elena; Oexle, Konrad; Rahi, Jugnoo S; Cumberland, Phillippa M; Schmitz-Valckenberg, Steffen; Fauser, Sascha; Bertelsen, Geir; Hoyng, Carel; Bergen, Arthur; Silva, Rufino; Wolf, Sebastian; Lotery, Andrew; Chakravarthy, Usha; Fletcher, Astrid; Klaver, Caroline C W

2016-02-01

The European Eye Epidemiology (E3) consortium is a recently formed consortium of 29 groups from 12 European countries. It already comprises 21 population-based studies and 20 other studies (case-control, cases only, randomized trials), providing ophthalmological data on approximately 170,000 European participants. The aim of the consortium is to promote and sustain collaboration and sharing of data and knowledge in the field of ophthalmic epidemiology in Europe, with particular focus on the harmonization of methods for future research, estimation and projection of frequency and impact of visual outcomes in European populations (including temporal trends and European subregions), identification of risk factors and pathways for eye diseases (lifestyle, vascular and metabolic factors, genetics, epigenetics and biomarkers) and development and validation of prediction models for eye diseases. Coordinating these existing data will allow a detailed study of the risk factors and consequences of eye diseases and visual impairment, including study of international geographical variation which is not possible in individual studies. It is expected that collaborative work on these existing data will provide additional knowledge, despite the fact that the risk factors and the methods for collecting them differ somewhat among the participating studies. Most studies also include biobanks of various biological samples, which will enable identification of biomarkers to detect and predict occurrence and progression of eye diseases. This article outlines the rationale of the consortium, its design and presents a summary of the methodology.

Occupational disease and workers' compensation: coverage, costs, and consequences.

PubMed

Leigh, J Paul; Robbins, John A

2004-01-01

Most of the costs of occupational disease are not covered by workers' compensation. First, the authors estimated the deaths and costs for all occupational disease in 1999, using epidemiological studies. Among the greatest contributors were job-related cancer, chronic respiratory disease, and circulatory disease. Second, the authors estimated the number of workers' compensation cases, costs, and deaths for 1999, using data from up to 16 states representing all regions of the country. Unlike the epidemiological studies that emphasized fatal diseases, the workers' compensation estimates emphasized nonfatal diseases and conditions like tendonitis and hernia. Comparisons of the epidemiological and workers' compensation estimates suggest that in 1999, workers' compensation missed roughly 46,000 to 93,000 deaths and 8 billion US dollars to 23 billion US dollars in medical costs. These deaths and costs represented substantial cost shifting from workers' compensation systems to individual workers, their families, private medical insurance, and taxpayers (through Medicare and Medicaid). Designing policies to reduce the cost shifting and its associated inefficiency will be challenging.

Setting research priorities for HIV/AIDS-related research in a post-graduate training programme: lessons learnt from the Nigeria Field Epidemiology and Laboratory Training Programme scientific workshop.

PubMed

Poggensee, Gabriele; Waziri, Ndadilnasiya Endie; Bashorun, Adebobola; Nguku, Patrick Mboya; Fawole, Olufunmilayo Ibitola; Sabitu, Kabir

2014-01-01

In Nigeria the current prevalence of HIV is 4.1% with over 3.5 million infected and estimated 1.5 million in need of anti-retroviral treatment. Epidemiological and implementation studies are necessary for monitoring and evaluation of interventions. To define research areas which can be addressed by participants of the Nigeria Field Epidemiology and Training Programme (NFELTP) a workshop was held in April 2013 in Abuja, Nigeria. Priority research areas were identified using criteria lists for ranking of the relevance of research questions. Based on a research matrix, NFELTP residents developed the aims and objectives, study design for HIV-related research proposals. This workshop was the first workshop held by the NFELTP to establish an inventory of research questions which can be addressed by the residents within their training period. This inventory will help to increase HIV/AIDS-related activities of NFELTP which are in accordance with research needs in Nigeria and PEPFAR objectives.

Occupational Disease and Workers’ Compensation: Coverage, Costs, and Consequences

PubMed Central

Leigh, J Paul; Robbins, John A

2004-01-01

Most of the costs of occupational disease are not covered by workers’ compensation. First, the authors estimated the deaths and costs for all occupational disease in 1999, using epidemiological studies. Among the greatest contributors were job-related cancer, chronic respiratory disease, and circulatory disease. Second, the authors estimated the number of workers’ compensation cases, costs, and deaths for 1999, using data from up to 16 states representing all regions of the country. Unlike the epidemiological studies that emphasized fatal diseases, the workers’ compensation estimates emphasized nonfatal diseases and conditions like tendonitis and hernia. Comparisons of the epidemiological and workers’ compensation estimates suggest that in 1999, workers’ compensation missed roughly 46,000 to 93,000 deaths and $8 billion to $23 billion in medical costs. These deaths and costs represented substantial cost shifting from workers’ compensation systems to individual workers, their families, private medical insurance, and taxpayers (through Medicare and Medicaid). Designing policies to reduce the cost shifting and its associated inefficiency will be challenging. PMID:15595947

9 CFR 78.1 - Definitions.

Code of Federal Regulations, 2012 CFR

2012-01-01

... designed by the herd owner, the owner's veterinarian if so requested, and a State representative or APHIS... handling facility for a maximum of 7 days and may not change ownership during this time. No cattle or bison... reinstated without repeating the certification process if epidemiological studies and bacteriological...

Establishing a Twin Register: An Invaluable Resource for (Behavior) Genetic, Epidemiological, Biomarker, and 'Omics' Studies.

PubMed

Odintsova, Veronika V; Willemsen, Gonneke; Dolan, Conor V; Hottenga, Jouke-Jan; Martin, Nicholas G; Slagboom, P Eline; Ordoñana, Juan R; Boomsma, Dorret I

2018-06-01

Twin registers are wonderful research resources for research applications in medical and behavioral genetics, epidemiology, psychology, molecular genetics, and other areas of research. New registers continue to be launched all over the world as researchers from different disciplines recognize the potential to boost and widen their research agenda. In this article, we discuss multiple aspects that need to be taken into account when initiating a register, from its preliminary sketch to its actual development. This encompasses aspects related to the strategic planning and key elements of research designs, promotion and management of a twin register, including recruitment and retaining of twins and family members of twins, phenotyping, database organization, and collaborations between registers. We also present information on questions unique to twin registers and twin-biobanks, such as the assessment of zygosity by SNP arrays, the design of (biomarker) studies involving related participants, and the analyses of clustered data. Altogether, we provide a number of basic guidelines and recommendations for reflection when planning a twin register.

Synthetic vitreous fibers: a review toxicology, epidemiology and regulations.

PubMed

Bernstein, David M

2007-01-01

This review addresses the characteristics which differentiate synthetic vitreous fibers (SVFs, e.g., fiber glass, stonewool, slagwool, refractory ceramic fibers, etc.), how these influence the potential biopersistence and toxicity, the most recent epidemiological results and the integration of these findings into the health and safety regulations in Europe and the United States. Also presented is the historical basis for the European classification directive. The use and equivalence of the chronic inhalation toxicology and chronic intraperitoneal injection studies in laboratory rodents for evaluation of fiber toxicology is assessed as well as the impact of dose selection and design on the validity of the study. While synthetic vitreous fibers can span a wide range of chemistries, recognition and understanding of the importance of biopersistence (ability to persist in the lung) in fiber toxicity has led to the development of more and more biosoluble fibers (that break down rapidly in the lung). Still, the epidemiological data available which are largely based upon the use of fibers in past decades, indicate that the SVF do not present a human health risk at current exposure levels. The animal toxicology and biopersistence data provide a coherent basis for understanding and evaluating the parameters which affect SVF toxicity. The current regulations are based upon an extensive knowledge base of chronic studies in laboratory rodents which confirm the relationship between chronic adverse effects and the biopersistence of the longer fibers that can not be fully phagocytised and efficiently cleared from the lung. The amorphous structure of synthetic vitreous fibers facilitates designing fibers in use today with low biopersistence. Both the epidemiological data and the animal studies database provide strong assurance that there is little if any health risk associated with the use of SVFs of low biopersistence. IARC (2001) reclassified these fibers from Category 2b to Category 3 (with RCF and special purpose fibers remaining in 2b) an event which has not been common in the history of these monographs.

Shift work, cancer and "white-box" epidemiology: Association and causation.

PubMed

Erren, Thomas C

2010-11-30

This commentary intends to instigate discussions about upcoming epidemiologic research, and its interpretation, into putative links between shift work, involving circadian disruption or chronodisruption [CD], and the development of internal cancers.In 2007, the International Agency for Research on Cancer (IARC) convened an expert group to examine the carcinogenicity of shift work, inter alia characterized by light exposures at unusual times. After a critical review of published data, the following was stated: "There is sufficient evidence in experimental animals for the carcinogenicity of light during the daily dark period (biological night)". However, in view of limited epidemiological evidence, it was overall concluded: "Shiftwork that involves circadian disruption is probably carcinogenic to humans (Group 2A)".Remarkably, the scenario around shift work, CD and internal cancers provides a unique case for "white-box" epidemiology: Research at many levels - from sub-cellular biochemistry, to whole cells, to organs, to organisms, including animals and humans - has suggested a series of quite precise and partly related causal mechanisms. This is in stark contrast to instances of "black box" or "stabs in the dark" epidemiology where causal mechanisms are neither known nor hypothesized or only poorly defined. The overriding theme that an adequate chronobiological organization of physiology can be critical for the protection against cancer builds the cornerstone of biological plausibility in this case.We can now benefit from biological plausibility in two ways: First, epidemiology should use biologically plausible insights into putative chains of causation between shift work and cancer to design future investigations. Second, when significant new data were to become available in coming years, IARC will re-evaluate cancer hazards associated with shift work. Biological plausibility may then be a key viewpoint to consider and, ultimately, to decide whether (or not) to pass from statistical associations, possibly detected in observational studies by then, to a verdict of causation.In the meantime, biological plausibility should not be invoked to facilitate publication of epidemiological research of inappropriate quality. Specific recommendations as to how to design, report and interpret epidemiological research into biologically plausible links between shift work and cancer are provided.Epidemiology is certainly a poor toolfor learning about the mechanismby which a disease is produced,but it has the tremendous advantagethat it focuses on the diseases and the deathsthat actually occur,and experience has shown that it continues to be second to none asa means of discovering linksin the chain of causationthat are capable of being broken.-Sir Richard Doll 1.

Adaptation of Chain Event Graphs for use with Case-Control Studies in Epidemiology.

PubMed

Keeble, Claire; Thwaites, Peter Adam; Barber, Stuart; Law, Graham Richard; Baxter, Paul David

2017-09-26

Case-control studies are used in epidemiology to try to uncover the causes of diseases, but are a retrospective study design known to suffer from non-participation and recall bias, which may explain their decreased popularity in recent years. Traditional analyses report usually only the odds ratio for given exposures and the binary disease status. Chain event graphs are a graphical representation of a statistical model derived from event trees which have been developed in artificial intelligence and statistics, and only recently introduced to the epidemiology literature. They are a modern Bayesian technique which enable prior knowledge to be incorporated into the data analysis using the agglomerative hierarchical clustering algorithm, used to form a suitable chain event graph. Additionally, they can account for missing data and be used to explore missingness mechanisms. Here we adapt the chain event graph framework to suit scenarios often encountered in case-control studies, to strengthen this study design which is time and financially efficient. We demonstrate eight adaptations to the graphs, which consist of two suitable for full case-control study analysis, four which can be used in interim analyses to explore biases, and two which aim to improve the ease and accuracy of analyses. The adaptations are illustrated with complete, reproducible, fully-interpreted examples, including the event tree and chain event graph. Chain event graphs are used here for the first time to summarise non-participation, data collection techniques, data reliability, and disease severity in case-control studies. We demonstrate how these features of a case-control study can be incorporated into the analysis to provide further insight, which can help to identify potential biases and lead to more accurate study results.

Indian Psychiatric epidemiological studies: Learning from the past

PubMed Central

Math, Suresh Bada; Srinivasaraju, Ravindra

2010-01-01

The objective of this paper is to provide a systematic review on the epidemiology of psychiatric disorders in India based on the data published from 1960 to 2009. Extensive search of PubMed, NeuroMed, Indian Journal of Psychiatry website and MEDLARS using search terms “psychiatry” “prevalence”, “community”, and “epidemiology” was done along with the manual search of journals and cross-references. Retrieved articles were systematically selected using specific inclusion and exclusion criteria. Epidemiological studies report prevalence rates for psychiatric disorders varying from 9.5 to 370/1000 population in India. These varying prevalence rates of mental disorders are not only specific to Indian studies but are also seen in international studies. Despite variations in the design of studies, available data from the Indian studies suggests that about 20% of the adult population in the community is affected with one or the other psychiatric disorder. Mental healthcare priorities need to be shifted from psychotic disorders to common mental disorders and from mental hospitals to primary health centers. Increase in invisible mental problems such as suicidal attempts, aggression and violence, widespread use of substances, increasing marital discord and divorce rates emphasize on the need to prioritize and make a paradigm shift in the strategies to promote and provide appropriate mental health services in the community. Future epidemiological research need to focus on the general population from longitudinal prospective involving multi-centers with assessment of disability, co-morbidity, functioning, family burden and quality of life. PMID:21836725

Epidemiology and outcome of the cardio-renal syndrome.

PubMed

Cruz, Dinna N; Gheorghiade, Mihai; Palazzuoli, Alberto; Palazuolli, Alberto; Ronco, Claudio; Bagshaw, Sean M

2011-11-01

Cardiac and kidney disease are common, increasingly encountered and often co-exist. Recently, the Acute Dialysis Quality Initiative (ADQI) Working Group convened a consensus conference to develop a classification scheme for the CRS and for five discrete subtypes. These CRS subtypes likely share pathophysiologic mechanisms, however, also have distinguishing clinical features, in terms of precipitating events, risk identification, natural history and outcomes. Knowledge of the epidemiology of heart-kidney interaction stratified by the proposed CRS subtypes is increasingly important for understanding the overall burden of disease for each CRS subtype, along with associated morbidity, mortality and health resource utilization. Likewise, an understanding of the epidemiology of CRS is necessary for characterizing whether there exists important knowledge gaps and to aid the in the design of clinical studies. In the most recent European and American guidelines for heart failure management, acute kidney injury and dysfunction were considered an index of poor prognosis. Paradoxically, however, in many randomized trials of interventions for patients with heart failure, those with kidney injury or dysfunction are often excluded. This review will provide a summary of the epidemiology of the cardio-renal syndrome and its subtypes.

Advances and Limitations of Disease Biogeography Using Ecological Niche Modeling

PubMed Central

Escobar, Luis E.; Craft, Meggan E.

2016-01-01

Mapping disease transmission risk is crucial in public and animal health for evidence based decision-making. Ecology and epidemiology are highly related disciplines that may contribute to improvements in mapping disease, which can be used to answer health related questions. Ecological niche modeling is increasingly used for understanding the biogeography of diseases in plants, animals, and humans. However, epidemiological applications of niche modeling approaches for disease mapping can fail to generate robust study designs, producing incomplete or incorrect inferences. This manuscript is an overview of the history and conceptual bases behind ecological niche modeling, specifically as applied to epidemiology and public health; it does not pretend to be an exhaustive and detailed description of ecological niche modeling literature and methods. Instead, this review includes selected state-of-the-science approaches and tools, providing a short guide to designing studies incorporating information on the type and quality of the input data (i.e., occurrences and environmental variables), identification and justification of the extent of the study area, and encourages users to explore and test diverse algorithms for more informed conclusions. We provide a friendly introduction to the field of disease biogeography presenting an updated guide for researchers looking to use ecological niche modeling for disease mapping. We anticipate that ecological niche modeling will soon be a critical tool for epidemiologists aiming to map disease transmission risk, forecast disease distribution under climate change scenarios, and identify landscape factors triggering outbreaks. PMID:27547199

Advances and Limitations of Disease Biogeography Using Ecological Niche Modeling.

PubMed

Escobar, Luis E; Craft, Meggan E

2016-01-01

Mapping disease transmission risk is crucial in public and animal health for evidence based decision-making. Ecology and epidemiology are highly related disciplines that may contribute to improvements in mapping disease, which can be used to answer health related questions. Ecological niche modeling is increasingly used for understanding the biogeography of diseases in plants, animals, and humans. However, epidemiological applications of niche modeling approaches for disease mapping can fail to generate robust study designs, producing incomplete or incorrect inferences. This manuscript is an overview of the history and conceptual bases behind ecological niche modeling, specifically as applied to epidemiology and public health; it does not pretend to be an exhaustive and detailed description of ecological niche modeling literature and methods. Instead, this review includes selected state-of-the-science approaches and tools, providing a short guide to designing studies incorporating information on the type and quality of the input data (i.e., occurrences and environmental variables), identification and justification of the extent of the study area, and encourages users to explore and test diverse algorithms for more informed conclusions. We provide a friendly introduction to the field of disease biogeography presenting an updated guide for researchers looking to use ecological niche modeling for disease mapping. We anticipate that ecological niche modeling will soon be a critical tool for epidemiologists aiming to map disease transmission risk, forecast disease distribution under climate change scenarios, and identify landscape factors triggering outbreaks.

Molecular markers in the epidemiology and diagnosis of coccidioidomycosis.

PubMed

Duarte-Escalante, Esperanza; Frías-De-León, María Guadalupe; Zúñiga, Gerardo; Martínez-Herrera, Erick; Acosta-Altamirano, Gustavo; Reyes-Montes, María Del Rocío

2014-01-01

The prevalence of coccidioidomycosis in endemic areas has been observed to increase daily. To understand the causes of the spread of the disease and design strategies for fungal detection in clinical and environmental samples, scientists have resorted to molecular tools that allow fungal detection in a natural environment, reliable identification in clinical cases and the study of biological characteristics, such as reproductive and genetic structure, demographic history and diversification. We conducted a review of the most important molecular markers in the epidemiology of Coccidioides spp. and the diagnosis of coccidioidomycosis. A literature search was performed for scientific publications concerning the application of molecular tools for the epidemiology and diagnosis of coccidioidomycosis. The use of molecular markers in the epidemiological study and diagnosis of coccidioidomycosis has allowed for the typing of Coccidioides spp. isolates, improved understanding of their mode of reproduction, genetic variation and speciation and resulted in the development specific, rapid and sensitive strategies for detecting the fungus in environmental and clinical samples. Molecular markers have revealed genetic variability in Coccidioides spp. This finding influences changes in the epidemiology of coccidioidomycosis, such as the emergence of more virulent or antifungal resistant genotypes. Furthermore, the molecular markers currently used to identify Coccidioides immitis and Coccidioides posadasii are specific and sensitive. However, they must be validated to determine their application in diagnosis. This manuscript is part of the series of works presented at the "V International Workshop: Molecular genetic approaches to the study of human pathogenic fungi" (Oaxaca, Mexico, 2012). Copyright © 2013 Revista Iberoamericana de Micología. Published by Elsevier Espana. All rights reserved.

What's all the fuss about? facts and figures about bone marrow failure and conditions.

PubMed

Mukherjee, Sudipto; Sekeres, Mikkael A

2012-12-01

The epidemiology of bone marrow failure conditions is not well understood. Although several population-based studies conducted in the last two decades have generated a wealth of information, it is still very challenging to interpret disease incidence and prevalence, particularly due to changes in disease classification, misdiagnosis of patients, frequent underreporting and use of different referent populations to calculate rates. Despite these limitations, the available epidemiologic data have revealed significant ethnic, geographic and clinical differences in disease biology that have implications for prevention and treatment strategies. With advances made in targeted therapies facilitated by identification of molecular biomarkers and increased use of curative bone marrow transplantation approach, the natural history of these disease entities is already changing. The epidemiology of these diseases seems to be the next frontier as knowledge gained about the risk factors and pathobiologic correlates could significantly help in designing patient-specific therapies with improved outcomes.

Molecular epidemiology of Crimean-Congo hemorrhagic fever in Bulgaria--An update.

PubMed

Papa, Anna; Pappa, Styliani; Panayotova, Elitsa; Papadopoulou, Elpida; Christova, Iva

2016-05-01

Crimean-Congo hemorrhagic fever (CCHF) is endemic in Bulgaria. During 2013-2014, 11 confirmed CCHF cases have been reported in the country (seven in 2013 and four in 2014). The present study provides the CCHF molecular epidemiology in Bulgaria based on all currently available S, M, and L RNA segment nucleotide sequences spanning the years 1978-2014. A relatively low genetic difference (0-6%, the maximum seen in the M RNA segment) was seen among the CCHFV sequences suggesting that a slow evolving CCHFV strain belonging to "Europe 1" clade is present in Bulgaria. Although the virus emerged in new foci during the recent years, it is more active in the established endemic foci which seem to offer the most suitable ecosystem and environment. Understanding the CCHF epidemiology and virus evolution is the basis for public health programs and vaccine design. © 2015 Wiley Periodicals, Inc.

Global epidemiology.

PubMed

Elliott, P

1993-01-01

Epidemiology is the study of the distribution and determinants of health and disease in human populations. Epidemiology on a global scale is severely constrained by the lack of data. In many countries, there are no comprehensive data on mortality or basic demographic data. Where data are available, findings on the relationship of environment to health across countries need to be interpreted with caution. For example, there is well-known variation in standards of medical practice and diagnosis, and in certification and coding, but there are also large differences in diet, the social environment and lifestyle--all of which strongly predict disease incidence. Inappropriate inference concerning aetiology made from such broad-scale studies may result in what has been termed the 'ecological fallacy'. A complementary approach is to collect and analyse data in standardized fashion as part of international collaborative studies. These can offer some important advantages over the more conventional single-centre design. Recent advances have meant that studies of environment and health can now--in some countries--be carried out using routine data at the small area level. Although problems of interpretation remain, they are generally less severe than in broad-scale studies. Examples of this approach are given.

Environmental Medicine Specialist (AFSC 90850).

ERIC Educational Resources Information Center

Air Univ., Gunter AFS, Ala. Extension Course Inst.

This five-volume student text is designed for use by Air Force personnel enrolled in a self-study extension course for environmental medical specialists. Covered in the individual volumes are (1) control of communicable diseases (principles of epidemiology and biology; food, waterborne, airborne, and sexually transmitted diseases; medical zoology;…

9 CFR 78.1 - Definitions.

Code of Federal Regulations, 2010 CFR

2010-01-01

... designed by the herd owner, the owner's veterinarian if so requested, and a State representative or APHIS... handling facility for a maximum of 7 days and may not change ownership during this time. No cattle or bison... process if epidemiological studies and bacteriological cultures conducted by an APHIS representative or...

Quasi-experimental study designs series-paper 7: assessing the assumptions.

PubMed

Bärnighausen, Till; Oldenburg, Catherine; Tugwell, Peter; Bommer, Christian; Ebert, Cara; Barreto, Mauricio; Djimeu, Eric; Haber, Noah; Waddington, Hugh; Rockers, Peter; Sianesi, Barbara; Bor, Jacob; Fink, Günther; Valentine, Jeffrey; Tanner, Jeffrey; Stanley, Tom; Sierra, Eduardo; Tchetgen, Eric Tchetgen; Atun, Rifat; Vollmer, Sebastian

2017-09-01

Quasi-experimental designs are gaining popularity in epidemiology and health systems research-in particular for the evaluation of health care practice, programs, and policy-because they allow strong causal inferences without randomized controlled experiments. We describe the concepts underlying five important quasi-experimental designs: Instrumental Variables, Regression Discontinuity, Interrupted Time Series, Fixed Effects, and Difference-in-Differences designs. We illustrate each of the designs with an example from health research. We then describe the assumptions required for each of the designs to ensure valid causal inference and discuss the tests available to examine the assumptions. Copyright © 2017 Elsevier Inc. All rights reserved.

Qualitative Epidemiologic Methods Can Improve Local Prevention Programming among Adolescents

ERIC Educational Resources Information Center

Daniulaityte, Raminta; Siegal, Harvey A.; Carlson, Robert G.; Kenne, Deric R.; Starr, Sanford; DeCamp, Brad

2004-01-01

The Ohio Substance Abuse Monitoring Network (OSAM) is designed to provide accurate, timely, qualitatively-oriented epidemiologic descriptions of substance abuse trends and emerging problems in the state's major urban and rural areas. Use of qualitative methods in identifying and assessing substance abuse practices in local communities is one of…

Methodology of a nationwide cross-sectional survey of prevalence and epidemiological patterns of hepatitis A, B and C infection in Brazil.

PubMed

Ximenes, Ricardo Arraes de Alencar; Pereira, Leila Maria Beltrão; Martelli, Celina Maria Turchi; Merchán-Hamann, Edgar; Stein, Airton Tetelbom; Figueiredo, Gerusa Maria; Braga, Maria Cynthia; Montarroyos, Ulisses Ramos; Brasil, Leila Melo; Turchi, Marília Dalva; Fonseca, José Carlos Ferraz da; Lima, Maria Luiza Carvalho de; Alencar, Luis Cláudio Arraes de; Costa, Marcelo; Coral, Gabriela; Moreira, Regina Celia; Cardoso, Maria Regina Alves

2010-09-01

A population-based survey to provide information on the prevalence of hepatitis viral infection and the pattern of risk factors was carried out in the urban population of all Brazilian state capitals and the Federal District, between 2005 and 2009. This paper describes the design and methodology of the study which involved a population aged 5 to 19 for hepatitis A and 10 to 69 for hepatitis B and C. Interviews and blood samples were obtained through household visits. The sample was selected using stratified multi-stage cluster sampling and was drawn with equal probability from each domain of study (region and age-group). Nationwide, 19,280 households and ~31,000 residents were selected. The study is large enough to detect prevalence of viral infection around 0.1% and risk factor assessments within each region. The methodology seems to be a viable way of differentiating between distinct epidemiological patterns of hepatitis A, B and C. These data will be of value for the evaluation of vaccination policies and for the design of control program strategies.

Dental Informatics tool "SOFPRO" for the study of oral submucous fibrosis.

PubMed

Erlewad, Dinesh Masajirao; Mundhe, Kalpana Anandrao; Hazarey, Vinay K

2016-01-01

Dental informatics is an evolving branch widely used in dental education and practice. Numerous applications that support clinical care, education and research have been developed. However, very few such applications are developed and utilized in the epidemiological studies of oral submucous fibrosis (OSF) which is affecting a significant population of Asian countries. To design and develop an user friendly software for the descriptive epidemiological study of OSF. With the help of a software engineer a computer program SOFPRO was designed and developed by using, Ms-Visual Basic 6.0 (VB), Ms-Access 2000, Crystal Report 7.0 and Ms-Paint in operating system XP. For the analysis purpose the available OSF data from the departmental precancer registry was fed into the SOFPRO. Known data, not known and null data are successfully accepted in data entry and represented in data analysis of OSF. Smooth working of SOFPRO and its correct data flow was tested against real-time data of OSF. SOFPRO was found to be a user friendly automated tool for easy data collection, retrieval, management and analysis of OSF patients.

Agent-Based vs. Equation-based Epidemiological Models:A Model Selection Case Study

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sukumar, Sreenivas R; Nutaro, James J

This paper is motivated by the need to design model validation strategies for epidemiological disease-spread models. We consider both agent-based and equation-based models of pandemic disease spread and study the nuances and complexities one has to consider from the perspective of model validation. For this purpose, we instantiate an equation based model and an agent based model of the 1918 Spanish flu and we leverage data published in the literature for our case- study. We present our observations from the perspective of each implementation and discuss the application of model-selection criteria to compare the risk in choosing one modeling paradigmmore » to another. We conclude with a discussion of our experience and document future ideas for a model validation framework.« less

Basic principles of test-negative design in evaluating influenza vaccine effectiveness.

PubMed

Fukushima, Wakaba; Hirota, Yoshio

2017-08-24

Based on the unique characteristics of influenza, the concept of "monitoring" influenza vaccine effectiveness (VE) across the seasons using the same observational study design has been developed. In recent years, there has been a growing number of influenza VE reports using the test-negative design, which can minimize both misclassification of diseases and confounding by health care-seeking behavior. Although the test-negative designs offer considerable advantages, there are some concerns that widespread use of the test-negative design without knowledge of the basic principles of epidemiology could produce invalid findings. In this article, we briefly review the basic concepts of the test-negative design with respect to classic study design such as cohort studies or case-control studies. We also mention selection bias, which may be of concern in some countries where rapid diagnostic testing is frequently used in routine clinical practices, as in Japan. Copyright © 2017. Published by Elsevier Ltd.

Atrazine and Pregnancy Outcomes: A Systematic Review of Epidemiologic Evidence

PubMed Central

Goodman, Michael; Mandel, Jack S; DeSesso, John M; Scialli, Anthony R

2014-01-01

Atrazine (ATR) is a commonly used agricultural herbicide that has been the subject of epidemiologic studies assessing its relation to reproductive health problems. This review evaluates both the consistency and the quality of epidemiologic evidence testing the hypothesis that ATR exposure, at usually encountered levels, is a risk factor for birth defects, small for gestational age birth weight, prematurity, miscarriages, and problems of fetal growth and development. We followed the current methodological guidelines for systematic reviews by using two independent researchers to identify, retrieve, and evaluate the relevant epidemiologic literature on the relation of ATR to various adverse outcomes of birth and pregnancy. Each eligible paper was summarized with respect to its methods and results with particular attention to study design and exposure assessment, which have been cited as the main areas of weakness in ATR research. As a quantitative meta-analysis was not feasible, the study results were categorized qualitatively as positive, null, or mixed. The literature on ATR and pregnancy-related health outcomes is growing rapidly, but the quality of the data is poor with most papers using aggregate rather than individual-level information. Without good quality data, the results are difficult to assess; however, it is worth noting that none of the outcome categories demonstrated consistent positive associations across studies. Considering the poor quality of the data and the lack of robust findings across studies, conclusions about a causal link between ATR and adverse pregnancy outcomes are not warranted. PMID:24797711

School, Community, and Family Working Together to Address Childhood Obesity: Perceptions from the KOALA Lifestyle Intervention Study

ERIC Educational Resources Information Center

Smibert, Asa; Abbott, Rebecca; Macdonald, Doune; Hogan, Anna; Leong, Gary

2010-01-01

Epidemiological data on childhood obesity has prompted a significant response from both governments and academics seeking to recommend solutions to the reported "crisis". The "Kinder Overweight Active Living Action" (KOALA) healthy lifestyle programme is a randomized obesity prevention and intervention study designed to provide an understanding of…

Race and Gender Differences in Perceived Caregiver Availability for Community-Dwelling Middle-Aged and Older Adults

ERIC Educational Resources Information Center

Roth, David L.; Haley, William E.; Wadley, Virginia G.; Clay, Olivio J.; Howard, George

2007-01-01

Purpose: Informal family caregivers are increasingly recognized as critical for meeting the needs of individuals with chronic diseases associated with aging. This study examined race and gender differences in perceived informal caregiver availability for participants aged 45 and older in a large national epidemiological study. Design and Methods:…

The Adolescent Outcome of Hyperactive Girls: Self-Report of Psychosocial Status

ERIC Educational Resources Information Center

Young, Susan; Heptinstall, Ellen; Sonuga-Barke, Edmund J. S.; Chadwick, Oliver; Taylor, Eric

2005-01-01

Background: The aim of the study was to clarify the developmental risk associated with hyperactive behaviour in girls in a longitudinal epidemiological design. Methods: This was investigated in a follow-up study of girls who were identified by parent and teacher ratings in a large community survey of 6- and 7-year-olds as showing pervasive…

Study Healthy Ageing and Intellectual Disabilities: Recruitment and Design

ERIC Educational Resources Information Center

Hilgenkamp, Thessa I. M.; Bastiaanse, Luc P.; Hermans, Heidi; Penning, Corine; van Wijck, Ruud; Evenhuis, Heleen M.

2011-01-01

Problems encountered in epidemiologic health research in older adults with intellectual disabilities (ID) are how to recruit a large-scale sample of participants and how to measure a range of health variables in such a group. This cross-sectional study into healthy ageing started with founding a consort of three large care providers with a total…

Evaluating a New Online Course in the Epidemiology of Infectious Diseases by Studying Student Learning Styles

ERIC Educational Resources Information Center

Rogers, James W.; Cox, James R.

2008-01-01

At RMIT University, students may now elect to study infectious diseases through a course called Outbreak--The Detection and Control of Infectious Disease. Outbreak was designed to simulate in an online class the effective teamwork required to bring resolution to outbreak crises and enable frameworks for future prevention. The appropriateness of…

A REVIEW OF HOUSEHOLD DRINKING WATER INTERVENTION TRIALS AND AN APPROACH TO THE ESTIMATION OF ENDEMIC WATERBORNE GASTROENTERITIS IN THE UNITED STATES

EPA Science Inventory

The incidence of acute gastrointestinal illness (AGI) attributable to public drinking water systems in the United States cannot be directly measured but must be estimated based on epidemiologic studies and other information. The randomized trial is one study design used to evalua...

Evaluation of Epidemiology and Animal Data for Risk Assessment: Chlorpyrifos Developmental Neurobehavioral Outcomes

PubMed Central

Li, Abby A.; Lowe, Kimberly A.; McIntosh, Laura J.; Mink, Pamela J.

2012-01-01

Developmental neurobehavioral outcomes attributed to exposure to chlorpyrifos (CPF) obtained from epidemiologic and animal studies published before June 2010 were reviewed for risk assessment purposes. For epidemiological studies, this review considered (1) overall strength of study design, (2) specificity of CPF exposure biomarkers, (3) potential for bias, and (4) Hill guidelines for causal inference. In the case of animal studies, this review focused on evaluating the consistency of outcomes for developmental neurobehavioral endpoints from in vivo mammalian studies that exposed dams and/or offspring to CPF prior to weaning. Developmental neuropharmacologic and neuropathologic outcomes were also evaluated. Experimental design and methods were examined as part of the weight of evidence. There was insufficient evidence that human developmental exposures to CPF produce adverse neurobehavioral effects in infants and children across different cohort studies that may be relevant to CPF exposure. In animals, few behavioral parameters were affected following gestational exposures to 1 mg/kg-d but were not consistently reported by different laboratories. For postnatal exposures, behavioral effects found in more than one study at 1 mg/kg-d were decreased errors on a radial arm maze in female rats and increased errors in males dosed subcutaneously from postnatal day (PND) 1 to 4. A similar finding was seen in rats exposed orally from PND 1 to 21 with incremental dose levels of 1, 2, and 4 mg/kg-d, but not in rats dosed with constant dose level of 1 mg/kg-d. Neurodevelopmental behavioral, pharmacological, and morphologic effects occurred at doses that produced significant brain or red blood cell acetylcholinesterase inhibition in dams or offspring. PMID:22401178

Thimerosal-containing vaccines and autistic spectrum disorder: a critical review of published original data.

PubMed

Parker, Sarah K; Schwartz, Benjamin; Todd, James; Pickering, Larry K

2004-09-01

The issue of thimerosal-containing vaccines as a possible cause of autistic spectrum disorders (ASD) and neurodevelopmental disorders (NDDs) has been a controversial topic since 1999. Although most practitioners are familiar with the controversy, many are not familiar with the type or quality of evidence in published articles that have addressed this issue. To assess the quality of evidence assessing a potential association between thimerosal-containing vaccines and autism and evaluate whether that evidence suggests accepting or rejecting the hypothesis, we systematically reviewed published articles that report original data pertinent to the potential association between thimerosal-containing vaccines and ASD/NDDs. Articles for analysis were identified in the National Library of Medicine's Medline database using a PubMed search of the English-language literature for articles published between 1966 and 2004, using keywords thimerosal, thiomersal, mercury, methylmercury, or ethylmercury alone and combined with keywords autistic disorder, autistic spectrum disorder, and neurodevelopment. In addition, we used the "related links" option in PubMed and reviewed the reference sections in the identified articles. All original articles that evaluated an association between thimerosal-containing vaccines and ASD/NDDs or pharmacokinetics of ethylmercury in vaccines were included. Twelve publications that met the selection criteria were identified by the literature search: 10 epidemiologic studies and 2 pharmacokinetic studies of ethylmercury. The design and quality of the studies showed significant variation. The preponderance of epidemiologic evidence does not support an association between thimerosal-containing vaccines and ASD. Epidemiologic studies that support an association are of poor quality and cannot be interpreted. Pharmacokinetic studies suggest that the half-life of ethylmercury is significantly shorter when compared with methylmercury. Studies do not demonstrate a link between thimerosal-containing vaccines and ASD, and the pharmacokinetics of ethylmercury make such an association less likely. Epidemiologic studies that support a link demonstrated significant design flaws that invalidate their conclusions. Evidence does not support a change in the standard of practice with regard to administration of thimerosal-containing vaccines in areas of the world where they are used.

Smoking and Ill Health: Does Lay Epidemiology Explain the Failure of Smoking Cessation Programs Among Deprived Populations?

PubMed Central

Lawlor, Debbie A; Frankel, Stephen; Shaw, Mary; Ebrahim, Shah; Smith, George Davey

2003-01-01

The resistance of disadvantaged groups to anti-smoking advice is remarkable. In relation to the study of differing cultures, there is a long-standing academic tradition assuming that behavior that may otherwise be difficult to understand is indeed rational within particular cultural contexts. Persistent smoking among the most deprived members of society may represent a rational response to their life chances informed by a lay epidemiology. Health promotion initiatives designed to reduce smoking among members of these groups may continue to fail unless the general health and life chances of such individuals are first improved. PMID:12554581

How to study the aetiology of burn injury: the epidemiological approach.

PubMed

Bouter, L M; Knipschild, P G; van Rijn, J L; Meertens, R M

1989-06-01

Effective prevention of burn injury should be based on sound aetiological knowledge. This article deals with epidemiological methods to study the incidence of burn injury as a function of its risk factors. Central methodological issues are comparability of baseline prognosis, comparability of measurements (of effects in cohort studies and of risk factors in case-control studies), and comparability of external circumstances. These principles are clarified with a number of fictitious examples of risk factors for burn injury. It is explained that in preventive trials comparability may be achieved by randomization, blinding and placebo intervention. The main tools in non-experimental studies are deliberate selection and multivariate analysis. Special attention is given to the definition of the source population and to reducing measurement incomparability in case-control studies. Some well-designed case-control studies following these principles might bring effective prevention of burn injury some steps nearer.

The Epidemiology of Longevity and Exceptional Survival

PubMed Central

Newman, Anne B.; Murabito, Joanne M.

2013-01-01

The field of the “epidemiology of longevity” has been expanding rapidly in recent years. Several long-term cohort studies have followed older adults long enough to identify the most long-lived and to define many factors that lead to a long life span. Very long-lived people such as centenarians have been examined using case-control study designs. Both cohort and case-control studies have been the subject of genome-wide association studies that have identified genetic variants associated with longevity. With growing recognition of the importance of rare variations, family studies of longevity will be useful. Most recently, exome and whole-genome sequencing, gene expression, and epigenetic studies have been undertaken to better define functional variation and regulation of the genome. In this review, we consider how these studies are leading to a deeper understanding of the underlying biologic pathways to longevity. PMID:23372024

Air pollution and health in Sri Lanka: a review of epidemiologic studies.

PubMed

Nandasena, Yatagama Lokuge S; Wickremasinghe, Ananda R; Sathiakumar, Nalini

2010-06-02

Air pollution is increasingly documented as a threat to public health in most developing countries. Evaluation of current air quality levels, regulatory standards and scientific literature on outdoor and indoor air pollution, and health effects are important to identify the burden, develop and implement interventions and to fill knowledge gaps in Sri Lanka. PUBMED and Medline databases, local journals and conference proceedings were searched for epidemiologic studies pertaining to air pollution and health effects in Sri Lanka. All the studies pertaining to air pollution and health effects were considered. Sixteen studies investigated the association between exposure to ambient or indoor air pollution (IAP) and various health outcomes ranging from respiratory symptoms, low birth weight and lung cancers. Of the sixteen, three used a case control design. Half of the studies collected exposure data only through questionnaires. There were positive associations between air pollution and adverse health effects in all studies. Methodological limitations in most of the studies resulted in poor quantification of risk estimates. A limited number of epidemiological studies in Sri Lanka have investigated the health effects of air pollution. Based on findings of studies and reported air quality levels, air pollution may be considered a neglected public health problem in Sri Lanka.

A Review of the Epidemiological Methods Used to Investigate the Health Impacts of Air Pollution around Major Industrial Areas

PubMed Central

Pascal, Laurence; Bidondo, Marie-Laure; Cochet, Amandine; Sarter, Hélène; Stempfelet, Morgane; Wagner, Vérène

2013-01-01

We performed a literature review to investigate how epidemiological studies have been used to assess the health consequences of living in the vicinity of industries. 77 papers on the chronic effects of air pollution around major industrial areas were reviewed. Major health themes were cancers (27 studies), morbidity (25 studies), mortality (7 studies), and birth outcome (7 studies). Only 3 studies investigated mental health. While studies were available from many different countries, a majority of papers came from the United Kingdom, Italy, and Spain. Several studies were motivated by concerns from the population or by previous observations of an overincidence of cases. Geographical ecological designs were largely used for studying cancer and mortality, including statistical designs to quantify a relationship between health indicators and exposure. Morbidity was frequently investigated through cross-sectional surveys on the respiratory health of children. Few multicenter studies were performed. In a majority of papers, exposed areas were defined based on the distance to the industry and were located from <2 km to >20 km from the plants. Improving the exposure assessment would be an asset to future studies. Criteria to include industries in multicenter studies should be defined. PMID:23818910

Epidemiology of East Coast fever (Theileria parva infection) in Kenya: past, present and the future.

PubMed

Gachohi, John; Skilton, Rob; Hansen, Frank; Ngumi, Priscilla; Kitala, Philip

2012-09-07

In this article, we review the epidemiology of East Coast fever (ECF), a tick-borne infection of cattle, in Kenya. The major factors associated with epidemiology of ECF include the agro-ecological zone (AEZ), livestock production system (LPS) and both animal breed and age. These factors appear to influence the epidemiology of ECF through structured gradients. We further show that the gradients are dynamically shaped by socio-demographic and environmental processes. For a vector-borne disease whose transmission depends on environmental characteristics that influence vector dynamics, a change in the environment implies a change in the epidemiology of the disease. The review recommends that future ECF epidemiological studies should account for these factors and the dynamic interactions between them. In Kenya, ECF control has previously relied predominantly on tick control using acaricides and chemotherapy while ECF immunization is steadily being disseminated. We highlight the contribution of ECF epidemiology and economics in the design of production system and/or geographical area-specific integrated control strategies based on both the dynamic epidemiological risk of the disease and economic impacts of control strategies. In all production systems (except marginal areas), economic analyses demonstrate that integrated control in which ECF immunization is always an important component, can play an important role in the overall control of the disease. Indeed, Kenya has recently approved ECF immunization in all production systems (except in marginal areas). If the infrastructure of the vaccine production and distribution can be heightened, large ECF endemic areas are expected to be endemically stable and the disease controlled. Finally, the review points the way for future research by identifying scenario analyses as a critical methodology on which to base future investigations on how both dynamic livestock management systems and patterns of land use influence the dynamics and complexity of ECF epidemiology and the implications for control.

Epidemiology of East Coast fever (Theileria parva infection) in Kenya: past, present and the future

PubMed Central

2012-01-01

In this article, we review the epidemiology of East Coast fever (ECF), a tick-borne infection of cattle, in Kenya. The major factors associated with epidemiology of ECF include the agro-ecological zone (AEZ), livestock production system (LPS) and both animal breed and age. These factors appear to influence the epidemiology of ECF through structured gradients. We further show that the gradients are dynamically shaped by socio-demographic and environmental processes. For a vector-borne disease whose transmission depends on environmental characteristics that influence vector dynamics, a change in the environment implies a change in the epidemiology of the disease. The review recommends that future ECF epidemiological studies should account for these factors and the dynamic interactions between them. In Kenya, ECF control has previously relied predominantly on tick control using acaricides and chemotherapy while ECF immunization is steadily being disseminated. We highlight the contribution of ECF epidemiology and economics in the design of production system and/or geographical area-specific integrated control strategies based on both the dynamic epidemiological risk of the disease and economic impacts of control strategies. In all production systems (except marginal areas), economic analyses demonstrate that integrated control in which ECF immunization is always an important component, can play an important role in the overall control of the disease. Indeed, Kenya has recently approved ECF immunization in all production systems (except in marginal areas). If the infrastructure of the vaccine production and distribution can be heightened, large ECF endemic areas are expected to be endemically stable and the disease controlled. Finally, the review points the way for future research by identifying scenario analyses as a critical methodology on which to base future investigations on how both dynamic livestock management systems and patterns of land use influence the dynamics and complexity of ECF epidemiology and the implications for control. PMID:22958352

The utility of web mining for epidemiological research: studying the association between parity and cancer risk.

PubMed

Tourassi, Georgia; Yoon, Hong-Jun; Xu, Songhua; Han, Xuesong

2016-05-01

The World Wide Web has emerged as a powerful data source for epidemiological studies related to infectious disease surveillance. However, its potential for cancer-related epidemiological discoveries is largely unexplored. Using advanced web crawling and tailored information extraction procedures, the authors automatically collected and analyzed the text content of 79 394 online obituary articles published between 1998 and 2014. The collected data included 51 911 cancer (27 330 breast; 9470 lung; 6496 pancreatic; 6342 ovarian; 2273 colon) and 27 483 non-cancer cases. With the derived information, the authors replicated a case-control study design to investigate the association between parity (i.e., childbearing) and cancer risk. Age-adjusted odds ratios (ORs) with 95% confidence intervals (CIs) were calculated for each cancer type and compared to those reported in large-scale epidemiological studies. Parity was found to be associated with a significantly reduced risk of breast cancer (OR = 0.78, 95% CI, 0.75-0.82), pancreatic cancer (OR = 0.78, 95% CI, 0.72-0.83), colon cancer (OR = 0.67, 95% CI, 0.60-0.74), and ovarian cancer (OR = 0.58, 95% CI, 0.54-0.62). Marginal association was found for lung cancer risk (OR = 0.87, 95% CI, 0.81-0.92). The linear trend between increased parity and reduced cancer risk was dramatically more pronounced for breast and ovarian cancer than the other cancers included in the analysis. This large web-mining study on parity and cancer risk produced findings very similar to those reported with traditional observational studies. It may be used as a promising strategy to generate study hypotheses for guiding and prioritizing future epidemiological studies. © The Author 2015. Published by Oxford University Press on behalf of the American Medical Informatics Association. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

[Quality standards for epidemiologic cohort studies : An evaluated catalogue of requirements for the conduct and preparation of cohort studies].

PubMed

Schmidt, Carsten Oliver; Krabbe, Christine E M; Schössow, Janka; Berger, Klaus; Enzenbach, Cornelia; Kamtsiuris, Panagiotis; Schöne, Gina; Houben, Robin; Meisinger, Christa; Bamberg, Fabian; Hendel, Thomas; Selder, Sonja; Nonnemacher, Michael; Moebus, Susanne; Stausberg, Jürgen

2018-01-01

Cohort studies are a longitudinal observational study type. They are firmly established within epidemiology to assess the course of diseases and risk factors. Yet, standards to describe and evaluate quality characteristics of cohort studies need further development. Within the TMF ("Technologie- und Methodenplattform für die vernetzte medizinische Forschung e. V.") project "Quality management standards in cohort studies", a catalogue of requirements was compiled and evaluated, focusing on the preparation and conduct of epidemiologic cohort studies. The catalogue of requirements was established based on a consensus process between representatives of seven German epidemiologic cohort studies. For this purpose, a set of expert meetings (telephone, face-to-face, web-based) was conducted and the importance of each element of the catalogue was assessed as well as its implementation. A catalogue of requirements with 138 requirements was consented. It is structured into ten sections: 1. Study documentation; 2. Selection of instruments; 3. Study implementation, 4. Organizational structure; 5. Qualification and certification; 6. Participant recruitment; 7. Preparation, conduct and follow-up processing of examinations; 8. Study logistics and maintenance, 9. Data capture and data management; 10. Reporting and monitoring. In total, 41 elements were categorized as being essential, 91 as important, and 6 as less important. The catalogue of requirements provides a guideline to improve the preparation and operation of cohort studies. The evaluation of the importance and degree of implementation of requirements depended on the study design. With adaptations, the catalogue might be transferable to other study types.

Effectiveness of workplace social distancing measures in reducing influenza transmission: a systematic review.

PubMed

Ahmed, Faruque; Zviedrite, Nicole; Uzicanin, Amra

2018-04-18

Social distancing is one of the community mitigation measures that may be recommended during influenza pandemics. Social distancing can reduce virus transmission by increasing physical distance or reducing frequency of congregation in socially dense community settings, such as schools or workplaces. We conducted a systematic review to assess the evidence that social distancing in non-healthcare workplaces reduces or slows influenza transmission. Electronic searches were conducted using MEDLINE, Embase, Scopus, Cochrane Library, PsycINFO, CINAHL, NIOSHTIC-2, and EconLit to identify studies published in English from January 1, 2000, through May 3, 2017. Data extraction was done by two reviewers independently. A narrative synthesis was performed. Fifteen studies, representing 12 modeling and three epidemiological, met the eligibility criteria. The epidemiological studies showed that social distancing was associated with a reduction in influenza-like illness and seroconversion to 2009 influenza A (H1N1). However, the overall risk of bias in the epidemiological studies was serious. The modeling studies estimated that workplace social distancing measures alone produced a median reduction of 23% in the cumulative influenza attack rate in the general population. It also delayed and reduced the peak influenza attack rate. The reduction in the cumulative attack rate was more pronounced when workplace social distancing was combined with other nonpharmaceutical or pharmaceutical interventions. However, the effectiveness was estimated to decline with higher basic reproduction number values, delayed triggering of workplace social distancing, or lower compliance. Modeling studies support social distancing in non-healthcare workplaces, but there is a paucity of well-designed epidemiological studies. PROSPERO registration # CRD42017065310.

The epidemiology and characteristics of stalking.

PubMed

Dressing, Harald; Kuehner, Christine; Gass, Peter

2006-07-01

This article summarizes major results in the field of epidemiology and characteristics of stalking, as published in literature between 2003 and October 2005. Although stalking had been only recently conceptualized, it soon became evident that it represents a significant social and medical problem. Community-based studies on the prevalence of stalking are scarce and predominantly from English-speaking countries. All epidemiological studies, however, revealed that stalking is a widespread phenomenon with lifetime prevalence rates of stalking victimization ranging 12-16% among women and 4-7% among men. With regard to the impact of stalking, studies suggest that stalking can cause serious economic, social, medical and psychiatric consequences. Growing evidence suggests that serious violence and even homicide may occur in the context of stalking, and research on risk assessment has yielded an improved understanding of risk factors. Research on therapy of stalkers and stalking victims is still at its beginning; however, there are some preliminary reports with encouraging results. Although there are research activities in the main fields, many basic questions still remain to be adequately addressed. Increased social and political awareness and expanded research funding are obligatory prerequisites to realize sound and well designed studies.

Diagnostic electrocardiography in epidemiological studies of Chagas' disease: multicenter evaluation of a standardized method.

PubMed

Lázzari, J O; Pereira, M; Antunes, C M; Guimarães, A; Moncayo, A; Chávez Domínguez, R; Hernández Pieretti, O; Macedo, V; Rassi, A; Maguire, J; Romero, A

1998-11-01

An electrocardiographic recording method with an associated reading guide, designed for epidemiological studies on Chagas' disease, was tested to assess its diagnostic reproducibility. Six cardiologists from five countries each read 100 electrocardiographic (ECG) tracings, including 30 from chronic chagasic patients, then reread them after an interval of 6 months. The readings were blind, with the tracings numbered randomly for the first reading and renumbered randomly for the second reading. The physicians, all experienced in interpreting ECGs from chagasic patients, followed printed instructions for reading the tracings. Reproducibility of the readings was evaluated using the kappa (kappa) index for concordance. The results showed a high degree of interobserver concordance with respect to the diagnosis of normal vs. abnormal tracings (kappa = 0.66; SE 0.02). While the interpretations of some categories of ECG abnormalities were highly reproducible, others, especially those having a low prevalence, showed lower levels of concordance. Intraobserver concordance was uniformly higher than interobserver concordance. The findings of this study justify the use by specialists of the recording of readings method proposed for epidemiological studies on Chagas' disease, but warrant caution in the interpretation of some categories of electrocardiographic alterations.

[Social determinants of odontalgia in epidemiological studies: theoretical review and proposed conceptual model].

PubMed

Bastos, João Luiz Dornelles; Gigante, Denise Petrucci; Peres, Karen Glazer; Nedel, Fúlvio Borges

2007-01-01

The epidemiological literature has been limited by the absence of a theoretical framework reflecting the complexity of causal mechanisms for the occurrence of health phenomena / disease conditions. In the field of oral epidemiology, such lack of theory also prevails, since dental caries the leading topic in oral research has been often studied through a biological and reductionist viewpoint. One of the most important consequences of dental caries is dental pain (odontalgia), which has received little attention in studies with sophisticated theoretical models and powerful designs to establish causal relationships. The purpose of this study is to review the scientific literature on the determinants of odontalgia and to discuss theories proposed for the explanation of the phenomenon. Conceptual models and emerging theories on the social determinants of oral health are revised, in an attempt to build up links with the bio-psychosocial pain model, proposing a more elaborate causal model for odontalgia. The framework suggests causal pathways between social structure and oral health through material, psychosocial and behavioral pathways. Aspects of the social structure are highlighted in order to relate them to odontalgia, stressing their importance in discussions of causal relationships in oral health research.

Sexually transmitted infections and risk of prostate cancer: review of historical and emerging hypotheses.

PubMed

Sutcliffe, Siobhan

2010-08-01

Since the early 1950s when sexually transmitted infections (STIs) were first proposed as a possible risk factor for prostate cancer, numerous epidemiologic studies have been conducted. Initially, these studies were primarily small case-control studies with retrospective, self-reported assessments of a narrow range of STIs, typically either any STIs, or gonorrhea and syphilis. However, as new STIs have been discovered/recognized, new and better tests to detect histories of STIs have been developed, and new resources for prostate cancer research have been created, epidemiologic studies have expanded to include a wide range of STIs, and have moved towards more rigorous, prospective study designs and serological assessment of STI histories. The results of these studies are reviewed and discussed, as well as possible new avenues of research, such as Trichomonas vaginalis infection and infections not typically considered to be sexually transmitted.

Suicidal behaviour on subway systems: a review of the epidemiology.

PubMed

Ratnayake, Ruwan; Links, Paul S; Eynan, Rahel

2007-11-01

Suicide on subway systems is a public health challenge that has been reported in urban centers worldwide. Our objective was to analyze studies of suicide on subway systems, develop a profile of characteristics that are suggestive of association with suicides or attempts, and show how this profile can inform prevention. A literature review involving epidemiology studies and studies relating to subway suicide was conducted. Twenty-eight studies were included in this review. Across studies, characteristics were not often assessed for risk factor status, although several characteristics were remarkably similar. Those attempting suicide on the subway appear to be affected by serious mental illness and have contact with mental health services before the suicidal behavior. Several characteristics may be shared among this population, emphasizing the potential for prevention in clinical and public health domains. Well-designed studies that utilize robust data collection and statistical methods are needed to establish the risk status associated with these characteristics.

Epidemiology and the Tobacco Epidemic: How Research on Tobacco and Health Shaped Epidemiology.

PubMed

Samet, Jonathan M

2016-03-01

In this article, I provide a perspective on the tobacco epidemic and epidemiology, describing the impact of the tobacco-caused disease epidemic on the field of epidemiology. Although there is an enormous body of epidemiologic evidence on the associations of smoking with health, little systematic attention has been given to how decades of research have affected epidemiology and its practice. I address the many advances that resulted from epidemiologic research on smoking and health, such as demonstration of the utility of observational designs and important parameters (the odds ratio and the population attributable risk), guidelines for causal inference, and systematic review approaches. I also cover unintended and adverse consequences for the field, including the strategy of doubt creation and the recruitment of epidemiologists by the tobacco industry to serve its mission. The paradigm of evidence-based action for addressing noncommunicable diseases began with the need to address the epidemic of tobacco-caused disease, an imperative for action documented by epidemiologic research. © The Author 2016. Published by Oxford University Press on behalf of the Johns Hopkins Bloomberg School of Public Health. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Environment And Genetics in Lung cancer Etiology (EAGLE) study: an integrative population-based case-control study of lung cancer.

PubMed

Landi, Maria Teresa; Consonni, Dario; Rotunno, Melissa; Bergen, Andrew W; Goldstein, Alisa M; Lubin, Jay H; Goldin, Lynn; Alavanja, Michael; Morgan, Glen; Subar, Amy F; Linnoila, Ilona; Previdi, Fabrizio; Corno, Massimo; Rubagotti, Maurizia; Marinelli, Barbara; Albetti, Benedetta; Colombi, Antonio; Tucker, Margaret; Wacholder, Sholom; Pesatori, Angela C; Caporaso, Neil E; Bertazzi, Pier Alberto

2008-06-06

Lung cancer is the leading cause of cancer mortality worldwide. Tobacco smoking is its primary cause, and yet the precise molecular alterations induced by smoking in lung tissue that lead to lung cancer and impact survival have remained obscure. A new framework of research is needed to address the challenges offered by this complex disease. We designed a large population-based case-control study that combines a traditional molecular epidemiology design with a more integrative approach to investigate the dynamic process that begins with smoking initiation, proceeds through dependency/smoking persistence, continues with lung cancer development and ends with progression to disseminated disease or response to therapy and survival. The study allows the integration of data from multiple sources in the same subjects (risk factors, germline variation, genomic alterations in tumors, and clinical endpoints) to tackle the disease etiology from different angles. Before beginning the study, we conducted a phone survey and pilot investigations to identify the best approach to ensure an acceptable participation in the study from cases and controls. Between 2002 and 2005, we enrolled 2101 incident primary lung cancer cases and 2120 population controls, with 86.6% and 72.4% participation rate, respectively, from a catchment area including 216 municipalities in the Lombardy region of Italy. Lung cancer cases were enrolled in 13 hospitals and population controls were randomly sampled from the area to match the cases by age, gender and residence. Detailed epidemiological information and biospecimens were collected from each participant, and clinical data and tissue specimens from the cases. Collection of follow-up data on treatment and survival is ongoing. EAGLE is a new population-based case-control study that explores the full spectrum of lung cancer etiology, from smoking addiction to lung cancer outcome, through examination of epidemiological, molecular, and clinical data. We have provided a detailed description of the study design, field activities, management, and opportunities for research following this integrative approach, which allows a sharper and more comprehensive vision of the complex nature of this disease. The study is poised to accelerate the emergence of new preventive and therapeutic strategies with potentially enormous impact on public health.

Epidemiology and clinical management of type 2 diabetes mellitus and associated comorbidities in Spain (e-Management study).

PubMed

Franch Nadal, Josep; Mata Cases, Manel; Mauricio Puente, Dídac

2016-11-01

Type 2 diabetes mellitus is currently the most frequent chronic metabolic disease. In spain, according to the di@bet.es study, its prevalence is 13.8% in the adult population (although it is undiagnosed in 6%). The main risk factor for type 2 diabetes mellitus is obesity. The severity of type 2 diabetes mellitus is determined not only by the presence of hyperglycaemia, but also by the coexistence of other risk factors such as hypertension or dyslipidaemia, which are often associated with the disease. Its impact on the presence of chronic diabetic complications varies. While hyperglycaemia mainly influences the presence of microvascular complications, hypertension, dyslipidaemia and smoking play a greater role in macrovascular atherosclerotic disease. One of the most powerful ways to study the epidemiology of the disease is through the use of large databases that analyse the situation in the routine clinical management of huge numbers of patients. Recently, the data provided by the e-Management Project, based on the SIDIAP database, have allowed updating of many data on the health care of diabetic persons in Catalonia. This not only allows determination of the epidemiology of the disease but is also a magnificent starting point for the design of future studies that will provide answers to more questions. However, the use of large databases is not free of certain problems, especially those concerning the reliability of registries. This article analyses some of the data obtained by the e-Management study and other spanish epidemiological studies of equal importance. Copyright © 2016 Elsevier España, S.L.U. All rights reserved.

Recent Approaches to Estimate Associations Between Source-Specific Air Pollution and Health.

PubMed

Krall, Jenna R; Strickland, Matthew J

2017-03-01

Estimating health effects associated with source-specific exposure is important for better understanding how pollution impacts health and for developing policies to better protect public health. Although epidemiologic studies of sources can be informative, these studies are challenging to conduct because source-specific exposures (e.g., particulate matter from vehicles) often are not directly observed and must be estimated. We reviewed recent studies that estimated associations between pollution sources and health to identify methodological developments designed to address important challenges. Notable advances in epidemiologic studies of sources include approaches for (1) propagating uncertainty in source estimation into health effect estimates, (2) assessing regional and seasonal variability in emissions sources and source-specific health effects, and (3) addressing potential confounding in estimated health effects. Novel methodological approaches to address challenges in studies of pollution sources, particularly evaluation of source-specific health effects, are important for determining how source-specific exposure impacts health.

Introducing E-learning in Epidemiology Course for Undergraduate Medical Students at the Faculty of Medicine, University of Belgrade: A Pilot Study.

PubMed

Gazibara, Tatjana; Marusic, Vuk; Maric, Gorica; Zaric, Milica; Vujcic, Isidora; Kisic-Tepavcevic, Darija; Maksimovic, Jadranka; Maksimovic, Nataša; Denic, Ljiljana Markovic; Grujicic, Sandra Sipetic; Pekmezovic, Tatjana; Grgurevic, Anita

2015-10-01

The aim of this study was to determine whether e-learning as a new teaching concept was acceptable for second-year undergraduates and to compare attitudes and exam results of students who followed electronic compared with classroom seminars. The electronic seminars (e-seminars) were developed several months prior to start of the epidemiology course for second-year students at the Faculty of Medicine, University of Belgrade. The students who applied for e-seminars accessed their content during summer semester (February-May) 2014. E-seminars were set according to the existing topics in practical workbook and designed using Moodle, a free, open-source, personal home page web application for producing modular internet-based courses. To evaluate the motives for enrollment and satisfaction with seminars, two surveys (pre- and post-course) were administered. Students' exam grades were registered over 4 exam sessions (June-October 2014) and compared according to seminar program. Out of 516 students in the second year, 60 (11.6 %) applied for e-seminars (mean age 21 years). Students considered the reason "It's easier to do assignments from home" as the strongest motive to participate. When compared to classroom seminars, students in e-seminars had significantly more fun (p = 0.003), thought that e-seminars were better mode to learn epidemiology (p = 0.030) and would recommend them to other colleagues (p = 0.001). There was no significant difference in average grade received at the oral exam in epidemiology (t = 0.071, p = 0.944). E-seminars in undergraduate epidemiology course add a novel, easy-to-follow and amusing mode of learning. Based on this pilot study, e-seminars in epidemiology will be available for next generations of students, while further improvement of e-seminars could include expansion of seminar syllabus and development of discussion fora.

Circular epidemiology.

PubMed

Kuller, L H

1999-11-01

Circular epidemiology can be defined as the continuation of specific types of epidemiologic studies beyond the point of reasonable doubt of the true existence of an important association or the absence of such an association. Circular epidemiology is an extreme example of studies of the consistency of associations. A basic problem for epidemiology is the lack of a systematic approach to acquiring new knowledge to reach a goal of improving public health and preventive medicine. For epidemiologists, research support unfortunately is biased toward the continued study of already proven hypotheses. Circular epidemiology, however, freezes at one point in the evolution of epidemiologic studies, failing to move from descriptive to analytical case-control and longitudinal studies, for example, to experimental, clinical trials. Good epidemiology journals are filled with very well-conducted epidemiologic studies that primarily repeat the obvious or are variations on the theme.

The National Center on Indigenous Hawaiian Behavioral Health Study of Prevalence of Psychiatric Disorders in Native Hawaiian Adolescents

ERIC Educational Resources Information Center

Andrade, Naleen N.; Hishinuma, Earl S.; McDermott, John F., Jr.; Johnson, Ronald C.; Goebert, Deborah A.; Makini, George K., Jr.; Nahulu, Linda B.; Yuen, Noelle Y. C.; McArdle, John J.; Bell, Cathy K.; Carlton, Barry S.; Miyamoto, Robin H.; Nishimura, Stephanie T.; Else, Iwalani R. N.; Guerrero, Anthony P. S.; Darmal, Arsalan; Yates, Alayne; Waldron, Jane A.

2006-01-01

Objectives: The prevalence rates of disorders among a community-based sample of Hawaiian youths were determined and compared to previously published epidemiological studies. Method: Using a two-phase design, 7,317 adolescents were surveyed (60% participation rate), from which 619 were selected in a modified random sample during the 1992-1993 to…

The Impact of Hearing Loss on Quality of Life in Older Adults

ERIC Educational Resources Information Center

Dalton, Dayna S.; Cruickshanks, Karen J.; Klein, Barbara E. K.; Klein, Ronald; Wiley, Terry L.; Nondahl, David M.

2003-01-01

Purpose: The authors investigate the impact of hearing loss on quality of life in a large population of older adults. Design and Methods: Data are from the 5-year follow-up Epidemiology of Hearing Loss Study, a population-based longitudinal study of age-related hearing impairment conducted in Beaver Dam, WI. Participants (N = 2,688) were 53-97…

Critical Appraisal Skills Among Canadian Obstetrics and Gynaecology Residents: How Do They Fare?

PubMed

Bougie, Olga; Posner, Glenn; Black, Amanda Y

2015-07-01

Evidence-based medicine has become the standard of care in clinical practice. In this study, our objectives were to (1) determine the type of epidemiology and/or biostatistical training being given in Canadian obstetrics and gynaecology post-graduate programs, (2) determine obstetrics and gynaecology residents' level of confidence with critical appraisal, and (3) assess knowledge of fundamental biostatistical and epidemiological principles among Canadian obstetrics and gynaecology trainees. During a national standardized in-training examination, all Canadian obstetrics and gynaecology residents were invited to complete an anonymous cross-sectional survey to determine their levels of confidence with critical appraisal. Fifteen critical appraisal questions were integrated into the standardized examination to assess critical appraisal skills objectively. Primary outcomes were the residents' level of confidence interpreting biostatistical results and applying research findings to clinical practice, their desire for more biostatistics/epidemiological training in residency, and their performance on knowledge questions. A total of 301 of 355 residents completed the survey (response rate=84.8%). Most (76.7%) had little/no confidence interpreting research statistics. Confidence was significantly higher in those with increased seniority (OR=1.93), in those who had taken a previous epidemiology/statistics course (OR=2.65), and in those who had prior publications (OR=1.82). Many (68%) had little/no confidence applying research findings to clinical practice. Confidence increased significantly with increasing training year (P<0.001) and with formal epidemiology training during residency (OR=2.01). The mean score of the 355 residents on the knowledge assessment questions was 69.8%. Increasing seniority was associated with improved overall test performance (P=0.02). Poorer performance topics included analytical study method (9.9%), study design (36.9%), and sample size (42.0%). Most (84.4%) wanted more epidemiology teaching. Canadian obstetrics and gynaecology residents may have the biostatistical and epidemiological knowledge to interpret results published in the literature, but lack confidence applying these skills in clinical settings. Most residents want additional training in these areas, and residency programs should include training in formal curriculums to improve their confidence and prepare them for a lifelong practice of evidence-based medicine.

Snippets from the past: is Flint, Michigan, the birthplace of the case-control study?

PubMed

Morabia, Alfredo

2013-12-15

In the summer of 1924, an outbreak of scarlet fever occurred in Flint, Michigan. Unable to trace it to the usual causes, particularly fresh milk, the Michigan Department of Health used a novel approach to disentangle the enigma: The 116 cases of scarlet fever were compared with 117 "controls" selected from neighbors of the quarantined cases and from patients at the City Health Center who had been treated for ailments unrelated to scarlet fever. The extraordinary culprit was ice cream, which had a frequent/occasional/none consumption prevalence of 60%, 34%, and 6% among the cases and 24%, 51%, and 25% among the controls, respectively. The 1925 report reads, "Detailed epidemiological investigation, by means of case histories and control histories on well persons, confirmed early suspicions and established the fact that the epidemic was spread by ice cream" (Am J Hyg. 1925;5(5):669-681). This forgotten epidemiologic study is the oldest study using the case-control design to have been resurrected thus far. The case-control study design may have been conceived simultaneously, but independently and for different purposes, in England (Janet Lane-Claypon's 1926 report on the determinants of breast cancer) and the United States.

Review of the epidemiologic literature on EMF and Health.

PubMed Central

Ahlbom, I C; Cardis, E; Green, A; Linet, M; Savitz, D; Swerdlow, A

2001-01-01

Exposures to extremely low-frequency electric and magnetic fields (EMF) emanating from the generation, transmission, and use of electricity are a ubiquitous part of modern life. Concern about potential adverse health effects was initially brought to prominence by an epidemiologic report two decades ago from Denver on childhood cancer. We reviewed the now voluminous epidemiologic literature on EMF and risks of chronic disease and conclude the following: a) The quality of epidemiologic studies on this topic has improved over time and several of the recent studies on childhood leukemia and on cancer associated with occupational exposure are close to the limit of what can realistically be achieved in terms of size of study and methodological rigor. b) Exposure assessment is a particular difficulty of EMF epidemiology, in several respects: i) The exposure is imperceptible, ubiquitous, has multiple sources, and can vary greatly over time and short distances. ii) The exposure period of relevance is before the date at which measurements can realistically be obtained and of unknown duration and induction period. iii) The appropriate exposure metric is not known and there are no biological data from which to impute it. c) In the absence of experimental evidence and given the methodological uncertainties in the epidemiologic literature, there is no chronic disease for which an etiological relation to EMF can be regarded as established. d) There has been a large body of high quality data for childhood cancer, and also for adult leukemia and brain tumor in relation to occupational exposure. Among all the outcomes evaluated in epidemiologic studies of EMF, childhood leukemia in relation to postnatal exposures above 0.4 microT is the one for which there is most evidence of an association. The relative risk has been estimated at 2.0 (95% confidence limit: 1.27-3.13) in a large pooled analysis. This is unlikely to be due to chance but, may be, in part, due to bias. This is difficult to interpret in the absence of a known mechanism or reproducible experimental support. In the large pooled analysis only 0.8% of all children were exposed above 0.4 microT. Further studies need to be designed to test specific hypotheses such as aspects of selection bias or exposure. On the basis of epidemiologic findings, evidence shows an association of amyotrophic lateral sclerosis with occupational EMF exposure although confounding is a potential explanation. Breast cancer, cardiovascular disease, and suicide and depression remain unresolved. PMID:11744509

Setting Research Priorities for HIV/AIDS-related research in a post-graduate training programme: lessons learnt from the Nigeria Field Epidemiology and Laboratory Training Programme scientific workshop

PubMed Central

Poggensee, Gabriele; Waziri, Ndadilnasiya Endie; Bashorun, Adebobola; Nguku, Patrick Mboya; Fawole, Olufunmilayo Ibitola; Sabitu, Kabir

2014-01-01

In Nigeria the current prevalence of HIV is 4.1% with over 3.5 million infected and estimated 1.5 million in need of anti-retroviral treatment. Epidemiological and implementation studies are necessary for monitoring and evaluation of interventions. To define research areas which can be addressed by participants of the Nigeria Field Epidemiology and Training Programme (NFELTP) a workshop was held in April 2013 in Abuja, Nigeria. Priority research areas were identified using criteria lists for ranking of the relevance of research questions. Based on a research matrix, NFELTP residents developed the aims and objectives, study design for HIV-related research proposals. This workshop was the first workshop held by the NFELTP to establish an inventory of research questions which can be addressed by the residents within their training period. This inventory will help to increase HIV/AIDS-related activities of NFELTP which are in accordance with research needs in Nigeria and PEPFAR objectives. PMID:25426209

[Use of satellites for public health purposes in tropical areas].

PubMed

Meynard, J B; Orlandi, E; Rogier, C; Sbai Idrissi, K; Deparis, X; Peyreffite, C; Lightburn, E; Malosse, D; Migliani, R; Spiegel, A; Boutin, J P

2003-01-01

The epidemiological hallmark of the new millennium has been the emergence or recrudescence of transmissible diseases with high epidemic potential. Disease tracking is becoming an increasingly global task requiring implementation of more and more sophisticated control strategies and facilities for sustainable development. A promising initiative involves the use of satellite technology to monitor and forecast the spread of disease. The Health Early Warning System (HEWS) was designed based on successful application of satellite data in food programs as well as in other areas (e.g. weather, farming and fishing). The HEWS integrates data from communications, remote-sensing and positioning satellites. The purpose of this review is to present the main studies containing satellite data on public health in tropical areas. Satellite data has allowed development of more reactive epidemiological tracking networks better suited to increasing population mobility, correlation of environmental factors (vegetation index, rainfall and ocean surface color) with human, animal and insect factors in epidemiological studies and assessment of the role of such factors in the development or reappearance of disease. Satellite technology holds great promise for more efficient management of public health problems in tropical areas.

Epidemiology and control of scabies in an Egyptian village.

PubMed

Hegazy, A A; Darwish, N M; Abdel-Hamid, I A; Hammad, S M

1999-04-01

Some studies have addressed the epidemiology of scabies among rural populations in developing countries; however, the epidemiology of scabies among the rural population in Egypt is unknown. We sought to determine the magnitude of scabies infestation in an Egyptian village and to evaluate the control measures after 1 year. This study was carried out on 3147 residents of Mit-Moaned village in Dakahlia govemorate, Egypt. It was a cross-sectional follow-up study where the same individuals examined in round I were re-examined in round III. The two rounds were separated by a period of 1 year, during which infested patients were followed up and new cases were discovered (round II). Patients and their household contacts received treatment with topical permethrin. Patients showing resistance to permethrin received a single oral dose of ivermectin. In round III, the overall prevalence rate of scabies was reduced from 5.4% in round I to 1.1%. The incidence of new cases among susceptible persons during round II was 1.1%. Scabies was significantly (P < 0.05) more prevalent among families of large size, high crowding index at night, low socioeconomic standards, and those receiving their water supply from a hand pump. Children younger than 10 years showed the highest prevalence. Our data provide the first complete picture of the epidemiology of scabies in rural Egypt. The epidemiologic characteristics of the disease should be considered in the design of disease control programs for other villages with scabies epidemics. Our findings revealed that good control was achieved with the following: increased awareness and better case finding, education of the staff at the rural health unit, improved hygiene measures, and massive treatment campaigns using effective drugs such as topical permethrin and oral ivermectin.

Optimal design of studies of influenza transmission in households. I: case-ascertained studies.

PubMed

Klick, B; Leung, G M; Cowling, B J

2012-01-01

Case-ascertained household transmission studies, in which households including an 'index case' are recruited and followed up, are invaluable to understanding the epidemiology of influenza. We used a simulation approach parameterized with data from household transmission studies to evaluate alternative study designs. We compared studies that relied on self-reported illness in household contacts vs. studies that used home visits to collect swab specimens for virological confirmation of secondary infections, allowing for the trade-off between sample size vs. intensity of follow-up given a fixed budget. For studies estimating the secondary attack proportion, 2-3 follow-up visits with specimens collected from all members regardless of illness were optimal. However, for studies comparing secondary attack proportions between two or more groups, such as controlled intervention studies, designs with reactive home visits following illness reports in contacts were most powerful, while a design with one home visit optimally timed also performed well.

Uses of ecologic analysis in epidemiologic research.

PubMed Central

Morgenstern, H

1982-01-01

Despite the widespread use of ecologic analysis in epidemiologic research and health planning, little attention has been given by health scientists and practitioners to the methodological aspects of this approach. This paper reviews the major types of ecologic study designs, the analytic methods appropriate for each, the limitations of ecologic data for making causal inferences and what can be done to minimize these problems, and the relative advantages of ecologic analysis. Numerous examples are provided to illustrate the important principles and methods. A careful distinction is made between ecologic studies that generate or test etiologic hypotheses and those that evaluate the impact of intervention programs or policies (given adequate knowledge of disease etiology). Failure to recognize this difference in the conduct of ecologic studies can lead to results that are not very informative or that are misinterpreted by others. PMID:7137430

Epidemiology of Patient Harms in New Zealand: Protocol of a General Practice Records Review Study

PubMed Central

Leitch, Sharon; Wallis, Katharine A; Eggleton, Kyle S; Cunningham, Wayne K; Williamson, Martyn I; Lillis, Steven; McMenamin, Andrew W; Tilyard, Murray W; Reith, David M; Samaranayaka, Ari; Hall, Jason E

2017-01-01

Background Knowing where and why harm occurs in general practice will assist patients, doctors, and others in making informed decisions about the risks and benefits of treatment options. Research to date has been unable to verify the safety of primary health care and epidemiological research about patient harms in general practice is now a top priority for advancing health systems safety. Objective We aim to study the incidence, distribution, severity, and preventability of the harms patients experience due to their health care, from the whole-of-health-system lens afforded by electronic general practice patient records. Methods “Harm” is defined as disease, injury, disability, suffering, and death, arising from the health system. The study design is a stratified, 2-level cluster, retrospective records review study. Both general practices and patients will be randomly selected so that the study’s results will apply nationally, after weighting. Stratification by practice size and rurality will allow comparisons between 6 study groups (large, medium-sized, small; urban and rural practices). Records of equal numbers of patients from each study group will be included in the study because there may be systematic differences in patient harms in different types of practices. Eight general practitioner investigators will review 3 years of electronic general practice health records (consultation notes, prescriptions, investigations, referrals, and summaries of hospital care) from 9000 patients registered in 60 general practices. Double-blinded reviews will check the concordance of reviewers’ assessments. Study data will comprise demographic data of all 9000 patients and reviewers’ assessments of whether patients experienced harm arising from health care. Where patient harm is identified, their types, preventability, severity, and outcomes will be coded using the Medical Dictionary for Regulatory Activities (MedDRA) 18.0. Results We have recruited practices and collected electronic records from 9078 patients. Reviews of these records are under way. The study is expected to be completed in August 2017. Conclusions The design of this complex study is presented with discussion on data collection methods, sampling weights, power analysis, and statistical approach. This study will show the epidemiology of patient harms recorded in general practice records for all of New Zealand and will show whether this epidemiology differs by rural location and clinic size. PMID:28119276

Disease control priorities in developing countries: health policy responses to epidemiological change.

PubMed Central

Jamison, D T; Mosley, W H

1991-01-01

Health systems in developing countries are facing major challenges in the 1990s and beyond because of a growing epidemiological diversity as a consequence of rapid economic development and declining fertility. The infectious and parasitic diseases of childhood must remain a priority at the same time the chronic diseases among adults are emerging as a serious problem. Health policymakers must engage in undertaking an epidemiological and economic analysis of the major disease problems, evaluating the cost-effectiveness of alternative intervention strategies; designing health care delivery systems; and, choosing what governments can do through persuasion, taxation, regulation, and provision of services. The World Bank has commissioned studies of over two dozen diseases in developing countries which have confirmed the priority of child survival interventions and revealed that interventions for many neglected and emerging adult health problems have comparable cost-effectiveness. Most developing countries lack information about most major diseases among adults, reflecting lack of national capacities in epidemiological and economic analyses, health technology assessment, and environmental monitoring and control. There is a critical need for national and international investment in capacity building and essential national health research to build the base for health policies. PMID:1983911

Reproductive and developmental effects of disinfection by-products in drinking water.

PubMed Central

Reif, J S; Hatch, M C; Bracken, M; Holmes, L B; Schwetz, B A; Singer, P C

1996-01-01

Recent epidemiologic studies have reported associations between the consumption of chlorinated drinking water and reproductive and developmental effects. Here we review the available epidemiologic data, assess the hazard potential posed by exposure to disinfection by-products, identify critical data gaps, and offer recommendations for further research. The epidemiologic evidence supporting associations between exposure to water disinfection by-products (DBPs) and adverse pregnancy outcomes is sparse, and positive findings should be interpreted cautiously. The methods used during the early stages of research in this area have been diverse. Variability in exposure assessment and endpoints makes it difficult to synthesize or combine the available data. Exposure misclassification and unmeasured confounding may have lead to bias in risk estimation. Future studies of reproductive outcome and exposure to chlorinated water should use improved methods for exposure assessment to 1) assure selection of appropriate exposure markers, 2) assess seasonal and annual fluctuations in DBPs, 3) assess variability within the distribution system, and 4) assess exposure through multiple routes such as bathing and showering, as well as consumption. Population-based studies should be conducted to evaluate male and female fertility, conception delay, growth retardation, and specific birth defects. The reproductive and developmental effects of exposure to DBPs could be efficiently explored in ongoing investigations by incorporating valid exposure markers and relevant questionnaire information. Future studies should make use of naturally occurring variability in the concentrations of DBPs and may incorporate biomarkers of exposure and effect in their design. Epidemiologic investigations should be conducted in parallel with laboratory-based and animal studies in a coordinated, multidisciplinary approach. PMID:8930546

Racial Differences in Suicidality in an Older Urban Population

ERIC Educational Resources Information Center

Cohen, Carl I.; Colemon, Yolonda; Yaffee, Robert; Casimir, Georges J.

2008-01-01

Purpose: This study used epidemiological data of older African Americans and Caucasians living in an urban community to compare those factors associated with active or passive suicidal ideation in each racial group. Design and Methods: Using 1990 census data for Brooklyn, New York, we attempted to interview all cognitively intact adults aged 55 or…

Estimation of the Prevalence of Autism Spectrum Disorder in South Korea, Revisited

ERIC Educational Resources Information Center

Pantelis, Peter C.; Kennedy, Daniel P.

2016-01-01

Two-phase designs in epidemiological studies of autism prevalence introduce methodological complications that can severely limit the precision of resulting estimates. If the assumptions used to derive the prevalence estimate are invalid or if the uncertainty surrounding these assumptions is not properly accounted for in the statistical inference…

Statistics and Epidemiology of Lead Poisoning (FY 72-L1).

ERIC Educational Resources Information Center

Morrison, John H., Jr.; And Others

This report is the first in a quarterly series which will contain statistics and epidemiologic notes on lead poisoning at both the national and local levels. This report contains (a) statistics on childhood lead poisoning; (b) a status report on the Community Lead Poisoning Data System, which was designed to assist local lead control programs and…

A Conceptual Framework for the Assessment of Cumulative Exposure to Air Pollution at a Fine Spatial Scale

PubMed Central

Wahida, Kihal-Talantikite; Padilla, Cindy M.; Denis, Zmirou-Navier; Olivier, Blanchard; Géraldine, Le Nir; Philippe, Quenel; Séverine, Deguen

2016-01-01

Many epidemiological studies examining long-term health effects of exposure to air pollutants have characterized exposure by the outdoor air concentrations at sites that may be distant to subjects’ residences at different points in time. The temporal and spatial mobility of subjects and the spatial scale of exposure assessment could thus lead to misclassification in the cumulative exposure estimation. This paper attempts to fill the gap regarding cumulative exposure assessment to air pollution at a fine spatial scale in epidemiological studies investigating long-term health effects. We propose a conceptual framework showing how major difficulties in cumulative long-term exposure assessment could be surmounted. We then illustrate this conceptual model on the case of exposure to NO2 following two steps: (i) retrospective reconstitution of NO2 concentrations at a fine spatial scale; and (ii) a novel approach to assigning the time-relevant exposure estimates at the census block level, using all available data on residential mobility throughout a 10- to 20-year period prior to that for which the health events are to be detected. Our conceptual framework is both flexible and convenient for the needs of different epidemiological study designs. PMID:26999170

A Conceptual Framework for the Assessment of Cumulative Exposure to Air Pollution at a Fine Spatial Scale.

PubMed

Wahida, Kihal-Talantikite; Padilla, Cindy M; Denis, Zmirou-Navier; Olivier, Blanchard; Géraldine, Le Nir; Philippe, Quenel; Séverine, Deguen

2016-03-15

Many epidemiological studies examining long-term health effects of exposure to air pollutants have characterized exposure by the outdoor air concentrations at sites that may be distant to subjects' residences at different points in time. The temporal and spatial mobility of subjects and the spatial scale of exposure assessment could thus lead to misclassification in the cumulative exposure estimation. This paper attempts to fill the gap regarding cumulative exposure assessment to air pollution at a fine spatial scale in epidemiological studies investigating long-term health effects. We propose a conceptual framework showing how major difficulties in cumulative long-term exposure assessment could be surmounted. We then illustrate this conceptual model on the case of exposure to NO₂ following two steps: (i) retrospective reconstitution of NO₂ concentrations at a fine spatial scale; and (ii) a novel approach to assigning the time-relevant exposure estimates at the census block level, using all available data on residential mobility throughout a 10- to 20-year period prior to that for which the health events are to be detected. Our conceptual framework is both flexible and convenient for the needs of different epidemiological study designs.

Recent transmission of Mycobacterium tuberculosis in China: the implication of molecular epidemiology for tuberculosis control.

PubMed

Yang, Chongguang; Gao, Qian

2018-02-01

Tuberculosis (TB) has remained an ongoing concern in China. The national scale-up of the Directly Observed Treatment, Short Course (DOTS) program has accelerated the fight against TB in China. Nevertheless, many challenges still remain, including the spread of drug-resistant strains, high disease burden in rural areas, and enormous rural-to-urban migrations. Whether incident active TB represents recent transmission or endogenous reactivation has helped to prioritize the strategies for TB control. Evidence from molecular epidemiology studies has delineated the recent transmission of Mycobacterium tuberculosis (M. tuberculosis) strains in many settings. However, the transmission patterns of TB in most areas of China are still not clear. Studies carried out to date could not capture the real burden of recent transmission of the disease in China because of the retrospective study design, incomplete sampling, and use of low-resolution genotyping methods. We reviewed the implementations of molecular epidemiology of TB in China, the estimated disease burden due to recent transmission of M. tuberculosis strains, the primary transmission of drug-resistant TB, and the evaluation of a feasible genotyping method of M. tuberculosis strains in circulation.

The AISPEP (Associazione Italiana Sindromi Pelvico Prostatiche) chronic prostatitis questionnaire (AISPEP-Q). focus on the disease: anamnestic data, life activities, symptoms, sexual habits, quality of life and knowledge about prostatitis from 93 questions answered on the Internet.

PubMed

Mazzoli, Sandra; Magri, Vittorio; Guercini, Federico; Simone, Alberto; Paolicchi, Fabio; Cai, Tommaso

2007-06-01

Chronic prostatitis (CP) has been described as one of the most common illnesses men aged < or = 50, showing a significant impact on patients' quality of life comparable with other chronic diseases, such as unstable angina or Crohn's disease. CP also is a social and economic problem due to its high incidence in the young male population and to the absence of evidence for the effectiveness of treatment. Today, however, although validated outcome questionnaires are available to follow prostatitis patients, diagnostic and treatment options are based on experience, expert opinion and poor clinical trial data. More extensive and better-designed epidemiological studies are needed to evaluate and describe prostatitis patient clinical characteristics, in order to carry out correct and useful treatment. The aim of this report is to present the new Associazione Italiana Sindromi Pelvico Prostatiche questionnaire (AISPEP-Q) in order to provide a tool for increasing knowledge in prostatitis patient characteristics and design future epidemiological studies.

Epidemiological approaches in the investigation of environmental causes of cancer: the case of dioxins and water disinfection by-products

PubMed Central

2011-01-01

I will refer in this paper to difficulties in research in environmental causes of cancer using as examples research on dioxins and on drinking water disinfection by-products (DBPs) that have created considerable controversy in the scientific and wider community. Dioxins are highly toxic chemicals that are animal carcinogens. For many years, evaluation of the carcinogenicity of dioxins in humans was based on case-control or registry based studies. The development of methods to measure dioxins in blood indicated that these studies suffered from extreme exposure misclassification. The conduct of large cohort studies of workers with widely contrasted exposures together with the use of biomarkers and models for exposure assessment, led to convincing evidence on the carcinogenicity of dioxins in humans. The high toxicity of a few dioxin congeners, the availability of a scheme to characterize the toxicity of a mixture of dioxins and related compounds and the long half-life of these compounds facilitated epidemiological research. Contrary to dioxins, trihalomethanes (THMs) and most of the hundreds of DBPs in drinking water are chemicals of low toxicity. For more than 15 years, the main evidence on the carcinogenicity of DBPs was through ecological or death certificate studies. More recent studies based on individual assessment confirmed increases in bladder cancer risk. However even those studies ignored the toxicological evidence on the importance of routes of exposure to DBPs other than ingestion and, probably, underestimated the risk. Persistence of weak study designs together with delays in advanced exposure assessment models led to delays in confirming early evidence on the carcinogenicity of DBPs. The evaluation of only a few chemicals when exposure is to a complex mixture remains a major problem in exposure assessment for DBPs. The success of epidemiological studies in identifying increased risks lies primarily on the wide contrast of exposure to DBPs in the general population that overcomes the significant exposure misclassification. Exposure assessment has been the Achilles heel for studies on dioxins and DBPs and cancer. The combination of powerful study designs, advanced exposure assessment together with a better understanding of mechanisms of disease and the use of biomarkers of exposure, led to the strengthening of the epidemiological evidence. PMID:21489213

Maternal arsenic exposure and birth outcomes: A comprehensive review of the epidemiologic literature focused on drinking water

PubMed Central

Bloom, Michael S.; Surdu, Simona; Neamtiu, Iulia A.; Gurzau, Eugen S.

2015-01-01

Inorganic arsenic (iAs) is a human toxicant to which populations may be exposed through consumption of geogenically contaminated groundwater. A growing body of experimental literature corroborates the reproductive toxicity of iAs; however, the results of human studies are inconsistent. Therefore, we conducted a comprehensive review of epidemiologic studies focused on drinking water iAs exposure and birth outcomes to assess the evidence for causality and to make recommendations for future study. We reviewed 18 English language papers assessing birth weight, gestational age, and birth size. Thirteen of the studies were conducted among populations with frequent exposure to high-level groundwater iAs contamination (>10 μg/L) and five studies were conducted in areas without recognized contamination. Most studies comprised small samples and used cross-sectional designs, often with ecologic exposure assessment strategies, although several large prospective investigations and studies with individual-level measurements were also reported. We conclude that: 1) the epidemiologic evidence for an increased risk of low birth weight (<2,500 grams) is insufficient, although there exists limited evidence for birth weight decreases; 2) the evidence for increased preterm delivery is insufficient; and, 3) there exists minimal evidence for decreased birth size. In further investigation of birth weight and size, we recommend incorporation of individual susceptibility measures using appropriate biomarkers, with collection timed to windows of vulnerability and speciated arsenic analysis, as well as consideration of populations exposed primarily to drinking water iAs contamination <10 μg/L. Given the large potential public health impact, additional, high quality epidemiologic studies are necessary to more definitively assess the risk. PMID:24713268

Maternal arsenic exposure and birth outcomes: a comprehensive review of the epidemiologic literature focused on drinking water.

PubMed

Bloom, Michael S; Surdu, Simona; Neamtiu, Iulia A; Gurzau, Eugen S

2014-09-01

Inorganic arsenic (iAs) is a human toxicant to which populations may be exposed through consumption of geogenically contaminated groundwater. A growing body of experimental literature corroborates the reproductive toxicity of iAs; however, the results of human studies are inconsistent. Therefore, we conducted a comprehensive review of epidemiologic studies focused on drinking water iAs exposure and birth outcomes to assess the evidence for causality and to make recommendations for future study. We reviewed 18 English language papers assessing birth weight, gestational age, and birth size. Thirteen of the studies were conducted among populations with frequent exposure to high-level groundwater iAs contamination (>10 μg/L) and five studies were conducted in areas without recognized contamination. Most studies comprised small samples and used cross-sectional designs, often with ecologic exposure assessment strategies, although several large prospective investigations and studies with individual-level measurements were also reported. We conclude that: (1) the epidemiologic evidence for an increased risk of low birth weight (<2500 g) is insufficient, although there exists limited evidence for birth weight decreases; (2) the evidence for increased preterm delivery is insufficient; and, (3) there exists minimal evidence for decreased birth size. In further investigation of birth weight and size, we recommend incorporation of individual susceptibility measures using appropriate biomarkers, with collection timed to windows of vulnerability and speciated arsenic analysis, as well as consideration of populations exposed primarily to drinking water iAs contamination <10 μg/L. Given the large potential public health impact, additional, high quality epidemiologic studies are necessary to more definitively assess the risk. Copyright © 2014 Elsevier GmbH. All rights reserved.

Study designs appropriate for the workplace.

PubMed

Hogue, C J

1986-01-01

Carlo and Hearn have called for "refinement of old [epidemiologic] methods and an ongoing evaluation of where methods fit in the overall scheme as we address the multiple complexities of reproductive hazard assessment." This review is an attempt to bring together the current state-of-the-art methods for problem definition and hypothesis testing available to the occupational epidemiologist. For problem definition, meta analysis can be utilized to narrow the field of potential causal hypotheses. Passive active surveillance may further refine issues for analytic research. Within analytic epidemiology, several methods may be appropriate for the workplace setting. Those discussed here may be used to estimate the risk ratio in either a fixed or dynamic population.

Strategies for evaluating the assumptions of the regression discontinuity design: a case study using a human papillomavirus vaccination programme.

PubMed

Smith, Leah M; Lévesque, Linda E; Kaufman, Jay S; Strumpf, Erin C

2017-06-01

The regression discontinuity design (RDD) is a quasi-experimental approach used to avoid confounding bias in the assessment of new policies and interventions. It is applied specifically in situations where individuals are assigned to a policy/intervention based on whether they are above or below a pre-specified cut-off on a continuously measured variable, such as birth date, income or weight. The strength of the design is that, provided individuals do not manipulate the value of this variable, assignment to the policy/intervention is considered as good as random for individuals close to the cut-off. Despite its popularity in fields like economics, the RDD remains relatively unknown in epidemiology where its application could be tremendously useful. In this paper, we provide a practical introduction to the RDD for health researchers, describe four empirically testable assumptions of the design and offer strategies that can be used to assess whether these assumptions are met in a given study. For illustrative purposes, we implement these strategies to assess whether the RDD is appropriate for a study of the impact of human papillomavirus vaccination on cervical dysplasia. We found that, whereas the assumptions of the RDD were generally satisfied in our study context, birth timing had the potential to confound our effect estimate in an unexpected way and therefore needed to be taken into account in the analysis. Our findings underscore the importance of assessing the validity of the assumptions of this design, testing them when possible and making adjustments as necessary to support valid causal inference. © The Author 2016. Published by Oxford University Press on behalf of the International Epidemiological Association

Epidemiology as discourse: the politics of development institutions in the Epidemiological Profile of El Salvador

PubMed Central

Aviles, L

2001-01-01

STUDY OBJECTIVE—To determine the ways in which institutions devoted to international development influence epidemiological studies.
DESIGN—This article takes a descriptive epidemiological study of El Salvador, Epidemiological Profile, conducted in 1994 by the US Agency for International Development, as a case study. The methods include discourse analysis in order to uncover the ideological basis of the report and its characteristics as a discourse of development.
SETTING—El Salvador.
RESULTS—The Epidemiological Profile theoretical basis, the epidemiological transition theory, embodies the ethnocentrism of a "colonizer's model of the world." This report follows the logic of a discourse of development by depoliticising development, creating abnormalities, and relying on the development consulting industry. The epidemiological transition theory serves as an ideology that legitimises and dissimulates the international order.
CONCLUSIONS—Even descriptive epidemiological assessments or epidemiological profiles are imbued with theoretical assumptions shaped by the institutional setting under which epidemiological investigations are conducted.


Keywords: El Salvador; politics PMID:11160170

Genetic variation and willingness to participate in epidemiologic research: data from three studies.

PubMed

Bhatti, Parveen; Sigurdson, Alice J; Wang, Sophia S; Chen, Jinbo; Rothman, Nathaniel; Hartge, Patricia; Bergen, Andrew W; Landi, Maria Teresa

2005-10-01

The differences in common genetic polymorphism frequencies by willingness to participate in epidemiologic studies are unexplored, but the same threats to internal validity operate as for studies with nongenetic information. We analyzed single nucleotide polymorphism genotypes, haplotypes, and short tandem repeats among control groups from three studies with different recruitment designs that included early, late, and never questionnaire responders, one or more participation incentives, and blood or buccal DNA collection. Among 2,955 individuals, we compared 108 genotypes, 8 haplotypes, and 9 to 15 short tandem repeats by respondent type. Among our main comparisons, single nucleotide polymorphism genotype frequencies differed significantly (P < 0.05) between respondent groups in six instances, with 13 expected by chance alone. When comparing the odds of carrying a variant among the various response groups, 19 odds ratios were /=1.40, levels that might be notably different. Among the various respondent group comparisons, haplotype and short tandem repeat frequencies were not significantly different by willingness to participate. We observed little evidence to suggest that genotype differences underlie response characteristics in molecular epidemiologic studies, but a greater variety of genes should be examined, including those related to behavioral traits potentially associated with willingness to participate. To the extent possible, investigators should evaluate their own genetic data for bias in response categories.

Epidemiology of respiratory health outcomes among World Trade Center disaster workers: review of the literature 10 years after the September 11, 2001 terrorist attacks.

PubMed

Ekenga, Christine C; Friedman-Jiménez, George

2011-09-01

Tens of thousands of workers participated in rescue, recovery, and cleanup activities at the World Trade Center (WTC) site in lower Manhattan after the terrorist attacks on September 11, 2001 (9/11). The collapse of the WTC resulted in the release of a variety of airborne toxicants. To date, respiratory symptoms and diseases have been among the most examined health outcomes in studies of WTC disaster workers. A systematic review of the literature on respiratory health outcomes was undertaken to describe the available information on new onset of respiratory symptoms and diseases among WTC disaster workers after September 11, 2001. Independent risk factors for respiratory health outcomes included being caught in the dust and debris cloud, early arrival at the WTC site, longer duration of work, and delaying mask and respirator use. Methodological challenges in epidemiologic studies of WTC disaster workers involved study design, exposure misclassification, and limited information on potential confounders and effect modifiers. In the 10 years after 9/11, epidemiologic studies of WTC disaster workers have been essential in investigating the respiratory health consequences of WTC exposure. Longitudinal studies along with continued medical surveillance will be vital in understanding the long-term respiratory burden associated with occupational WTC exposure.

Flavonoids, Flavonoid Subclasses, and Esophageal Cancer Risk: A Meta-Analysis of Epidemiologic Studies.

PubMed

Cui, Lingling; Liu, Xinxin; Tian, Yalan; Xie, Chen; Li, Qianwen; Cui, Han; Sun, Changqing

2016-06-08

Flavonoids have been suggested to play a chemopreventive role in carcinogenesis. However, the epidemiologic studies assessing dietary intake of flavonoids and esophageal cancer risk have yielded inconsistent results. This study was designed to examine the association between flavonoids, each flavonoid subclass, and the risk of esophageal cancer with a meta-analysis approach. We searched for all relevant studies with a prospective cohort or case-control study design published from January 1990 to April 2016, using PUBMED, EMBASE, and Web of Science. Pooled odds ratios (ORs) were calculated using fixed or random-effect models. In total, seven articles including 2629 cases and 481,193 non-cases were selected for the meta-analysis. Comparing the highest-intake patients with the lowest-intake patients for total flavonoids and for each flavonoid subclass, we found that anthocyanidins (OR = 0.60, 95% CI: 0.49-0.74), flavanones (OR = 0.65, 95% CI: 0.49-0.86), and flavones (OR = 0.78, 95% CI 0.64-0.95) were inversely associated with the risk of esophageal cancer. However, total flavonoids showed marginal association with esophageal cancer risk (OR = 0.78, 95% CI: 0.59-1.04). In conclusion, our study suggested that dietary intake of total flavonoids, anthocyanidins, flavanones, and flavones might reduce the risk of esophageal cancer.

Gene-environment interactions in cancer epidemiology: a National Cancer Institute Think Tank report.

PubMed

Hutter, Carolyn M; Mechanic, Leah E; Chatterjee, Nilanjan; Kraft, Peter; Gillanders, Elizabeth M

2013-11-01

Cancer risk is determined by a complex interplay of genetic and environmental factors. Genome-wide association studies (GWAS) have identified hundreds of common (minor allele frequency [MAF] > 0.05) and less common (0.01 < MAF < 0.05) genetic variants associated with cancer. The marginal effects of most of these variants have been small (odds ratios: 1.1-1.4). There remain unanswered questions on how best to incorporate the joint effects of genes and environment, including gene-environment (G × E) interactions, into epidemiologic studies of cancer. To help address these questions, and to better inform research priorities and allocation of resources, the National Cancer Institute sponsored a "Gene-Environment Think Tank" on January 10-11, 2012. The objective of the Think Tank was to facilitate discussions on (1) the state of the science, (2) the goals of G × E interaction studies in cancer epidemiology, and (3) opportunities for developing novel study designs and analysis tools. This report summarizes the Think Tank discussion, with a focus on contemporary approaches to the analysis of G × E interactions. Selecting the appropriate methods requires first identifying the relevant scientific question and rationale, with an important distinction made between analyses aiming to characterize the joint effects of putative or established genetic and environmental factors and analyses aiming to discover novel risk factors or novel interaction effects. Other discussion items include measurement error, statistical power, significance, and replication. Additional designs, exposure assessments, and analytical approaches need to be considered as we move from the current small number of success stories to a fuller understanding of the interplay of genetic and environmental factors. © 2013 WILEY PERIODICALS, INC.

Gene-Environment Interactions in Cancer Epidemiology: A National Cancer Institute Think Tank Report

PubMed Central

Hutter, Carolyn M.; Mechanic, Leah E.; Chatterjee, Nilanjan; Kraft, Peter; Gillander, Elizabeth M.

2014-01-01

Cancer risk is determined by a complex interplay of genetic and environmental factors. Genome-wide association studies (GWAS) have identified hundreds of common (minor allele frequency [MAF]>0.05) and less common (0.01

Lessons from the 2004 Asian tsunami: epidemiological and nosological debates in the diagnosis of post-traumatic stress disorder in non-Western post-disaster communities.

PubMed

Rajkumar, A P; Mohan, T S P; Tharyan, P

2013-03-01

The nosological validity of post-traumatic stress disorder (PTSD) remains controversial in non-Western communities. After natural disasters, epidemiological studies often overlook these conceptual debates and assess post-traumatic stress symptoms (PTSS) by short screening instruments. Such PTSS estimates are reported as inflated prevalence rates of PTSD in post-disaster settings. To discuss the prevalence and determinants of PTSS within the context of pertinent epidemiological and nosological debates. We assessed PTSS and grief symptoms of 643 survivors from five Indian villages struck by the Asian tsunami using the Impact of Events Scale - Revised and Complicated Grief Assessment Scale. We adopted a case control design and employed complex sample multiple logistic regression statistics to study the determinants of PTSS. The prevalence of PTSS was 15.1% (95% CI 12.3%-17.9%). PTSS was significantly associated with traumatic grief, female gender, physical injury, death of children and financial losses, but not with functional disability (p = .91). Although PTSS were common in this population, elevating them to a psychiatric construct of PTSD is questionable, when functional impairment and avoidance behaviours were absent. Grief reactions, socio-economic burden, and poor support systems contribute towards PTSS. We highlight the important issues regarding the nosological validity and epidemiology of PTSD in non-Western communities.

Epidemiology for the nuclear medicine technologist.

PubMed

Bolus, N E

2001-09-01

The purpose of this article is to introduce the nuclear medicine technologist to the field of epidemiology. There are many applications of epidemiology in nuclear medicine, including research studies that deal with the causes of disease or ways to prevent disease from occurring and investigating the possible effects of ionizing radiation on occupational workers and the general public. One use of an epidemiologic study is to suggest ways to reduce the occurrence of a disease. After reading this article, the nuclear medicine technologist will be familiar with: a) the history and underlying assumptions of epidemiology, b) types of epidemiologic studies, c) what is a valid statistical association for an epidemiologic study, d) proper judgment of cause and effect relationships, e) definitions of epidemiologic terms, and f) an example of a nuclear medicine research study.

Glycomic Analysis of Prostate Cancer

DTIC Science & Technology

2012-07-01

allowed measurements of N-glycans and the Clinical Molecular Epidemiology Shared Resources which provided services for biological sample storage and...select N-glycans for the detection of prostate cancer. Aim3. Perform an exploratory study of N-glycans in urine of the participants and correlation of...cases. We have designed a pooled-unpooled study where initial discovery is conducted in smaller number of pooled samples followed by analysis of

Preventing Depression in Later Life: Translation From Concept to Experimental Design and Implementation

PubMed Central

Sriwattanakomen, Roy; Ford, Angela F.; Thomas, Stephen B.; Miller, Mark D.; Stack, Jacqueline A.; Morse, Jennifer Q.; Kasckow, John; Brown, Charlotte; Reynolds, Charles F.

2009-01-01

Objective The authors detail the public health need for depression prevention research and the decisions made in designing an experiment testing problem solving therapy as “indicated” preventive intervention for high-risk older adults with subsyndromal depression. Special attention is given to the recruitment of African Americans because of well-documented inequalities in mental health services and depression treatment outcomes between races. Methods A total of 306 subjects (half white, half African American) with scores of 16 or higher on the Center for Epidemiological Studies of Depression Scale, but with no history of major depressive disorder in the past 12 months, are being recruited and randomly assigned to either problem solving therapy-primary care or to a dietary education control condition. Time to, and rate of, incident episodes of major depressive disorder are to be modeled using survival analysis. Level of depressive symptoms will be analyzed via a mixed models approach. Results Twenty-two subjects have been recruited into the study, and to date eight have completed the randomly assigned intervention and postintervention assessment. Four of 22 have exited after developing major depressive episodes. None have complained about study procedures or demands. Implementation in a variety of community settings is going well. Conclusion The data collected to date support the feasibility of translating from epidemiology to RCT design and implementation of empirical depression prevention research in later life. PMID:18515690

Dental Informatics tool “SOFPRO” for the study of oral submucous fibrosis

PubMed Central

Erlewad, Dinesh Masajirao; Mundhe, Kalpana Anandrao; Hazarey, Vinay K

2016-01-01

Background: Dental informatics is an evolving branch widely used in dental education and practice. Numerous applications that support clinical care, education and research have been developed. However, very few such applications are developed and utilized in the epidemiological studies of oral submucous fibrosis (OSF) which is affecting a significant population of Asian countries. Aims and Objectives: To design and develop an user friendly software for the descriptive epidemiological study of OSF. Materials and Methods: With the help of a software engineer a computer program SOFPRO was designed and developed by using, Ms-Visual Basic 6.0 (VB), Ms-Access 2000, Crystal Report 7.0 and Ms-Paint in operating system XP. For the analysis purpose the available OSF data from the departmental precancer registry was fed into the SOFPRO. Results: Known data, not known and null data are successfully accepted in data entry and represented in data analysis of OSF. Smooth working of SOFPRO and its correct data flow was tested against real-time data of OSF. Conclusion: SOFPRO was found to be a user friendly automated tool for easy data collection, retrieval, management and analysis of OSF patients. PMID:27601808

Assessment of Worldwide Acute Kidney Injury Epidemiology in Neonates: Design of a Retrospective Cohort Study.

PubMed

Jetton, Jennifer G; Guillet, Ronnie; Askenazi, David J; Dill, Lynn; Jacobs, Judd; Kent, Alison L; Selewski, David T; Abitbol, Carolyn L; Kaskel, Fredrick J; Mhanna, Maroun J; Ambalavanan, Namasivayam; Charlton, Jennifer R

2016-01-01

Acute kidney injury (AKI) affects ~30% of hospitalized neonates. Critical to advancing our understanding of neonatal AKI is collaborative research among neonatologists and nephrologists. The Neonatal Kidney Collaborative (NKC) is an international, multidisciplinary group dedicated to investigating neonatal AKI. The AWAKEN study (Assessment of Worldwide Acute Kidney injury Epidemiology in Neonates) was designed to describe the epidemiology of neonatal AKI, validate the definition of neonatal AKI, identify primary risk factors for neonatal AKI, and investigate the contribution of fluid management to AKI events and short-term outcomes. The NKC was established with at least one pediatric nephrologist and neonatologist from 24 institutions in 4 countries (USA, Canada, Australia, and India). A Steering Committee and four subcommittees were created. The database subcommittee oversaw the development of the web-based database (MediData Rave™) that captured all NICU admissions from 1/1/14 to 3/31/14. Inclusion and exclusion criteria were applied to eliminate neonates with a low likelihood of AKI. Data collection included: (1) baseline demographic information; (2) daily physiologic parameters and care received during the first week of life; (3) weekly "snapshots"; (4) discharge information including growth parameters, final diagnoses, discharge medications, and need for renal replacement therapy; and (5) all serum creatinine values. AWAKEN was proposed as human subjects research. The study design allowed for a waiver of informed consent/parental permission. NKC investigators will disseminate data through peer-reviewed publications and educational conferences. The purpose of this publication is to describe the formation of the NKC, the establishment of the AWAKEN cohort and database, future directions, and a few "lessons learned." The AWAKEN database includes ~325 unique variables and >4 million discrete data points. AWAKEN will be the largest, most inclusive neonatal AKI study to date. In addition to validating the neonatal AKI definition and identifying risk factors for AKI, this study will uncover variations in practice patterns related to fluid provision, renal function monitoring, and involvement of pediatric nephrologists during hospitalization. The AWAKEN study will position the NKC to achieve the long-term goal of improving the lives, health, and well-being of newborns at risk for kidney disease.

Interview with Alexander Cohen.

PubMed

Cohen, Alexander Ander

2017-05-01

Ander Cohen speaks to Adam Price-Evans, Commissioning Editor of Future Cardiology: Alexander (Ander) Cohen MBBS (Hons), MSc, MD, FRACP is a vascular physician and epidemiologist at Guy's and St Thomas' Hospital, King's College (London, UK). He graduated with honors in medicine and honors in surgery from the University of Melbourne, Australia, and became a fellow of the Royal Australasian College of Physicians in 1990. He was awarded an MSc in Epidemiology from the London School of Hygiene and Tropical Medicine, University of London in 1991 with a thesis on the metabolic syndrome in South-Asian populations. In 1998, he was awarded an MD with a thesis on the epidemiology of venous thromboembolism and thromboprophylaxis. In addition to his clinical work, he is involved in designing, managing and analyzing clinical trials from Phase I to IV. He is the Chairman and a member of many international steering committees for multicenter trials, epidemiological and pharmacoeconomic studies, and was previously the Director of Clinical Research and an Epidemiologist in Thrombosis Research at King's College Hospital.

Genetic characterization, molecular epidemiology, and phylogenetic relationships of insect-specific viruses in the taxon Negevirus

PubMed Central

Nunes, Marcio R.T.; Contreras-Gutierrez, María Angélica; Guzman, Hilda; Martins, Livia C.; Barbirato, Mayla Feitoza; Savit, Chelsea; Balta, Victoria; Uribe, Sandra; Vivero, Rafael; Suaza, Juan David; Oliveira, Hamilton; Nunes Neto, Joaquin P.; Carvalho, Valeria L.; da Silva, Sandro Patroca; Cardoso, Jedson F.; de Oliveira, Rodrigo Santo; da Silva Lemos, Poliana; Wood, Thomas G.; Widen, Steven G.; Vasconcelos, Pedro F.C.; Fish, Durland; Vasilakis, Nikos; Tesh, Robert B.

2017-01-01

The recently described taxon Negevirus is comprised of a diverse group of insect-specific viruses isolated from mosquitoes and phlebotomine sandflies. In this study, a comprehensive genetic characterization, molecular, epidemiological and evolutionary analyses were conducted on nearly full-length sequences of 91 new negevirus isolates obtained in Brazil, Colombia, Peru, Panama, USA and Nepal. We demonstrated that these arthropod restricted viruses are clustered in two major phylogenetic groups with origins related to three plant virus genera (Cilevirus, Higrevirus and Blunevirus). Molecular analyses demonstrated that specific host correlations are not present with most negeviruses; instead, high genetic variability, wide host-range, and cross-species transmission were noted. The data presented here also revealed the existence of five novel insect-specific viruses falling into two arthropod-restrictive virus taxa, previously proposed as distinct genera, designated Nelorpivirus and Sandewavirus. Our results provide a better understanding of the molecular epidemiology, evolution, taxonomy and stability of this group of insect-restricted viruses. PMID:28193550

Genetic characterization, molecular epidemiology, and phylogenetic relationships of insect-specific viruses in the taxon Negevirus.

PubMed

Nunes, Marcio R T; Contreras-Gutierrez, María Angélica; Guzman, Hilda; Martins, Livia C; Barbirato, Mayla Feitoza; Savit, Chelsea; Balta, Victoria; Uribe, Sandra; Vivero, Rafael; Suaza, Juan David; Oliveira, Hamilton; Nunes Neto, Joaquin P; Carvalho, Valeria L; da Silva, Sandro Patroca; Cardoso, Jedson F; de Oliveira, Rodrigo Santo; da Silva Lemos, Poliana; Wood, Thomas G; Widen, Steven G; Vasconcelos, Pedro F C; Fish, Durland; Vasilakis, Nikos; Tesh, Robert B

2017-04-01

The recently described taxon Negevirus is comprised of a diverse group of insect-specific viruses isolated from mosquitoes and phlebotomine sandflies. In this study, a comprehensive genetic characterization, molecular, epidemiological and evolutionary analyses were conducted on nearly full-length sequences of 91 new negevirus isolates obtained in Brazil, Colombia, Peru, Panama, USA and Nepal. We demonstrated that these arthropod restricted viruses are clustered in two major phylogenetic groups with origins related to three plant virus genera (Cilevirus, Higrevirus and Blunevirus). Molecular analyses demonstrated that specific host correlations are not present with most negeviruses; instead, high genetic variability, wide host-range, and cross-species transmission were noted. The data presented here also revealed the existence of five novel insect-specific viruses falling into two arthropod-restrictive virus taxa, previously proposed as distinct genera, designated Nelorpivirus and Sandewavirus. Our results provide a better understanding of the molecular epidemiology, evolution, taxonomy and stability of this group of insect-restricted viruses. Copyright © 2017 Elsevier Inc. All rights reserved.

Designing an Internationally Accessible Web-Based Questionnaire to Discover Risk Factors for Amyotrophic Lateral Sclerosis: A Case-Control Study

PubMed Central

Parkin Kullmann, Jane Alana; Hayes, Susan; Wang, Min-Xia

2015-01-01

Background Amyotrophic lateral sclerosis (ALS) is a progressive neurodegenerative disease with a typical survival of three to five years. Epidemiological studies using paper-based questionnaires in individual countries or continents have failed to find widely accepted risk factors for the disease. The advantages of online versus paper-based questionnaires have been extensively reviewed, but few online epidemiological studies into human neurodegenerative diseases have so far been undertaken. Objective To design a Web-based questionnaire to identify environmental risk factors for ALS and enable international comparisons of these risk factors. Methods A Web-based epidemiological questionnaire for ALS has been developed based on experience gained from administering a previous continent-wide paper-based questionnaire for this disease. New and modified questions have been added from our previous paper-based questionnaire, from literature searches, and from validated ALS questionnaires supplied by other investigators. New criteria to allow the separation of familial and sporadic ALS cases have been included. The questionnaire addresses many risk factors that have already been proposed for ALS, as well as a number that have not yet been rigorously examined. To encourage participation, responses are collected anonymously and no personally identifiable information is requested. The survey is being translated into a number of languages which will allow many people around the world to read and answer it in their own language. Results After the questionnaire had been online for 4 months, it had 379 respondents compared to only 46 respondents for the same initial period using a paper-based questionnaire. The average age of the first 379 web questionnaire respondents was 54 years compared to the average age of 60 years for the first 379 paper questionnaire respondents. The questionnaire is soon to be promoted in a number of countries through ALS associations and disease registries. Conclusions Web-based questionnaires are a time- and resource-efficient method for performing large epidemiological studies of neurodegenerative diseases such as ALS. The ability to compare risk factors between different countries using the same analysis tool will be of particular value for finding robust risk factors that underlie ALS. PMID:26239255

Asia, Australia and New Zealand Dyspnoea in Emergency Departments (AANZDEM) study: Rationale, design and analysis.

PubMed

Kelly, Anne-Maree; Keijzers, Gerben; Klim, Sharon; Graham, Colin A; Craig, Simon; Kuan, Win Sen; Jones, Peter; Holdgate, Anna; Lawoko, Charles; Laribi, Said

2015-06-01

Shortness of breath is a common reason for ED attendance. This international study aims to describe the epidemiology of dyspnoea presenting to EDs in the South East Asia-Pacific region, to compare disease patterns across regions, to understand how conditions are investigated and treated, and to assess quality of care. This is a prospective, interrupted time series cohort study conducted in EDs in Australia, New Zealand, Singapore, Hong Kong and Malaysia of consecutive adult patients presenting to the ED with dyspnoea as a main symptom. Data were collected over three 72 h periods in May, August and October 2014 (autumn, winter and spring), and included demographics, comorbidities, mode of arrival, usual medications, pre-hospital treatment, initial assessment, ED investigations, treatment in the ED, ED diagnosis, disposition from ED, in-hospital outcome and final hospital diagnosis. The primary outcomes of interest are the epidemiology and outcome of patients presenting to ED with dyspnoea. Secondary outcomes of interest are seasonal and geographic comparisons of diagnoses and outcomes, disease-specific descriptions of epidemiology, investigation, treatment and disposition, and compliance with treatment guidelines. This novel study will explore dyspnoea from the viewpoint of the patient's symptom (shortness of breath) rather than that of a single disease. The results will provide robust data about the epidemiology, investigation, treatment and disposition of this diverse patient group. The obtained data also have the potential to inform service planning and to quantify the proportion of patients with mixed cardiac and respiratory disease. © 2015 Australasian College for Emergency Medicine and Australasian Society for Emergency Medicine.

[Food industry funding and epidemiologic research in public health nutrition].

PubMed

Navarrete-Muñoz, Eva María; Tardón, Adonina; Romaguera, Dora; Martínez-González, Miguel Ángel; Vioque, Jesús

The interests of the food industry to fund nutrition and health research are not limited to promoting scientific advances. Recently, several systematic reviews conducted about the effect of sugar-sweetened beverages and health outcomes have shown some biased conclusions in studies that acknowledge industry sponsorship. In this context, the Nutrition Working Group of the Spanish Epidemiology Society presented a scientific session entitled Food industry and epidemiologic research at its annual meeting. In a round table, four experts in nutrition research presented their points of view about whether the food industry should fund nutrition-related research and the related potential conflicts of interest of the food industry. All the experts agreed not only on defending independence in nutritional epidemiology regarding the design, interpretation and conclusion of their studies but also on the crucial need for guaranteed scientific rigor, scientific quality of the results and measures to protect studies against potential biases related to the conflicts of interest of funding by the food industry. Drs Pérez-Farinós and Romaguera believe that the most effective way to prevent conflicts of interest would be not to allow the food industry to fund nutrition research; Drs Marcos and Martínez-González suggested the need to establish mechanisms and strategies to prevent the potential influences of the food industry in selecting researchers or institutional sponsorship and in the analysis and results of the studies, to ensure maximum independence for researchers, as well as their professional ethics. Copyright © 2017 SESPAS. Publicado por Elsevier España, S.L.U. All rights reserved.

Cultural concepts of distress and psychiatric disorders: literature review and research recommendations for global mental health epidemiology

PubMed Central

Kohrt, Brandon A; Rasmussen, Andrew; Kaiser, Bonnie N; Haroz, Emily E; Maharjan, Sujen M; Mutamba, Byamah B; de Jong, Joop TVM; Hinton, Devon E

2014-01-01

Background Burgeoning global mental health endeavors have renewed debates about cultural applicability of psychiatric categories. This study’s goal is to review strengths and limitations of literature comparing psychiatric categories with cultural concepts of distress (CCD) such as cultural syndromes, culture-bound syndromes, and idioms of distress. Methods The Systematic Assessment of Quality in Observational Research (SAQOR) was adapted based on cultural psychiatry principles to develop a Cultural Psychiatry Epidemiology version (SAQOR-CPE), which was used to rate quality of quantitative studies comparing CCD and psychiatric categories. A meta-analysis was performed for each psychiatric category. Results Forty-five studies met inclusion criteria, with 18 782 unique participants. Primary objectives of the studies included comparing CCD and psychiatric disorders (51%), assessing risk factors for CCD (18%) and instrument validation (16%). Only 27% of studies met SAQOR-CPE criteria for medium quality, with the remainder low or very low quality. Only 29% of studies employed representative samples, 53% used validated outcome measures, 44% included function assessments and 44% controlled for confounding. Meta-analyses for anxiety, depression, PTSD and somatization revealed high heterogeneity (I2 > 75%). Only general psychological distress had low heterogeneity (I2 = 8%) with a summary effect odds ratio of 5.39 (95% CI 4.71-6.17). Associations between CCD and psychiatric disorders were influenced by methodological issues, such as validation designs (β = 16.27, 95%CI 12.75-19.79) and use of CCD multi-item checklists (β = 6.10, 95%CI 1.89-10.31). Higher quality studies demonstrated weaker associations of CCD and psychiatric disorders. Conclusions Cultural concepts of distress are not inherently unamenable to epidemiological study. However, poor study quality impedes conceptual advancement and service application. With improved study design and reporting using guidelines such as the SAQOR-CPE, CCD research can enhance detection of mental health problems, reduce cultural biases in diagnostic criteria and increase cultural salience of intervention trial outcomes. PMID:24366490

Design and validity of a clinic-based case-control study on the molecular epidemiology of lymphoma

PubMed Central

Cerhan, James R; Fredericksen, Zachary S; Wang, Alice H; Habermann, Thomas M; Kay, Neil E; Macon, William R; Cunningham, Julie M; Shanafelt, Tait D; Ansell, Stephen M; Call, Timothy G; Witzig, Thomas E; Slager, Susan L; Liebow, Mark

2011-01-01

We present the design features and implementation of a clinic-based case-control study on the molecular epidemiology of lymphoma conducted at the Mayo Clinic (Rochester, Minnesota, USA), and then assess the internal and external validity of the study. Cases were newly diagnosed lymphoma patients from Minnesota, Iowa and Wisconsin seen at Mayo and controls were patients from the same region without lymphoma who had a pre-scheduled general medical examination, frequency matched on age, sex and residence. Overall response rates were 67% for cases and 70% for controls; response rates were lower for cases and controls over age 70 years, cases with more aggressive disease, and controls from the local area, although absolute differences were modest. Cases and controls were well-balanced on age, sex, and residence characteristics. Demographic and disease characteristics of NHL cases were similar to population-based cancer registry data. Control distributions were similar to population-based data on lifestyle factors and minor allele frequencies of over 500 SNPs, although smoking rates were slightly lower. Associations with NHL in the Mayo study for smoking, alcohol use, family history of lymphoma, autoimmune disease, asthma, eczema, body mass index, and single nucleotide polymorphisms in TNF (rs1800629), LTA (rs909253), and IL10 (rs1800896) were at a magnitude consistent with estimates from pooled studies in InterLymph, with history of any allergy the only directly discordant result in the Mayo study. These data suggest that this study should have strong internal and external validity. This framework may be useful to others who are designing a similar study. PMID:21686124

Standards for reporting chronic periodontitis prevalence and severity in epidemiologic studies: Proposed standards from the Joint EU/USA Periodontal Epidemiology Working Group.

PubMed

Holtfreter, Birte; Albandar, Jasim M; Dietrich, Thomas; Dye, Bruce A; Eaton, Kenneth A; Eke, Paul I; Papapanou, Panos N; Kocher, Thomas

2015-05-01

Periodontal diseases are common and their prevalence varies in different populations. However, prevalence estimates are influenced by the methodology used, including measurement techniques, case definitions, and periodontal examination protocols, as well as differences in oral health status. As a consequence, comparisons between populations are severely hampered and inferences regarding the global variation in prevalence can hardly be drawn. To overcome these limitations, the authors suggest standardized principles for the reporting of the prevalence and severity of periodontal diseases in future epidemiological studies. These principles include the comprehensive reporting of the study design, the recording protocol, and specific subject-related and oral data. Further, a range of periodontal data should be reported in the total population and within specific age groups. Periodontal data include the prevalence and extent of clinical attachment loss (CAL) and probing depth (PD) on site and tooth level according to specific thresholds, mean CAL/PD, the CDC/AAP case definition, and bleeding on probing. Consistent implementation of these standards in future studies will ensure improved reporting quality, permit meaningful comparisons of the prevalence of periodontal diseases across populations, and provide better insights into the determinants of such variation. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Next Generation Analytic Tools for Large Scale Genetic Epidemiology Studies of Complex Diseases

PubMed Central

Mechanic, Leah E.; Chen, Huann-Sheng; Amos, Christopher I.; Chatterjee, Nilanjan; Cox, Nancy J.; Divi, Rao L.; Fan, Ruzong; Harris, Emily L.; Jacobs, Kevin; Kraft, Peter; Leal, Suzanne M.; McAllister, Kimberly; Moore, Jason H.; Paltoo, Dina N.; Province, Michael A.; Ramos, Erin M.; Ritchie, Marylyn D.; Roeder, Kathryn; Schaid, Daniel J.; Stephens, Matthew; Thomas, Duncan C.; Weinberg, Clarice R.; Witte, John S.; Zhang, Shunpu; Zöllner, Sebastian; Feuer, Eric J.; Gillanders, Elizabeth M.

2012-01-01

Over the past several years, genome-wide association studies (GWAS) have succeeded in identifying hundreds of genetic markers associated with common diseases. However, most of these markers confer relatively small increments of risk and explain only a small proportion of familial clustering. To identify obstacles to future progress in genetic epidemiology research and provide recommendations to NIH for overcoming these barriers, the National Cancer Institute sponsored a workshop entitled “Next Generation Analytic Tools for Large-Scale Genetic Epidemiology Studies of Complex Diseases” on September 15–16, 2010. The goal of the workshop was to facilitate discussions on (1) statistical strategies and methods to efficiently identify genetic and environmental factors contributing to the risk of complex disease; and (2) how to develop, apply, and evaluate these strategies for the design, analysis, and interpretation of large-scale complex disease association studies in order to guide NIH in setting the future agenda in this area of research. The workshop was organized as a series of short presentations covering scientific (gene-gene and gene-environment interaction, complex phenotypes, and rare variants and next generation sequencing) and methodological (simulation modeling and computational resources and data management) topic areas. Specific needs to advance the field were identified during each session and are summarized. PMID:22147673

Use of World Wide Web-based directories for tracing subjects in epidemiologic studies.

PubMed

Koo, M M; Rohan, T E

2000-11-01

The recent availability of World Wide Web-based directories has opened up a new approach for tracing subjects in epidemiologic studies. The completeness of two World Wide Web-based directories (Canada411 and InfoSpace Canada) for subject tracing was evaluated by using a randomized crossover design for 346 adults randomly selected from respondents in an ongoing cohort study. About half (56.4%) of the subjects were successfully located by using either Canada411 or InfoSpace. Of the 43.6% of the subjects who could not be located using either directory, the majority (73.5%) were female. Overall, there was no clear advantage of one directory over the other. Although Canada411 could find significantly more subjects than InfoSpace, the number of potential matches returned by Canada411 was also higher, which meant that a longer list of potential matches had to be examined before a true match could be found. One strategy to minimize the number of potential matches per true match is to first search by InfoSpace with the last name and first name, then by Canada411 with the last name and first name, and finally by InfoSpace with the last name and first initial. Internet-based searches represent a potentially useful approach to tracing subjects in epidemiologic studies.

A systematic review of human and animal leptospirosis in the Pacific Islands reveals pathogen and reservoir diversity.

PubMed

Guernier, Vanina; Goarant, Cyrille; Benschop, Jackie; Lau, Colleen L

2018-05-14

The Pacific Islands have environmental conditions highly favourable for transmission of leptospirosis, a neglected zoonosis with highest incidence in the tropics, and Oceania in particular. Recent reports confirm the emergence and outbreaks of leptospirosis in the Pacific Islands, but the epidemiology and drivers of transmission of human and animal leptospirosis are poorly documented, especially in the more isolated and less developed islands. We conducted a systematic review of human and animal leptospirosis within 25 Pacific Islands (PIs) in Polynesia, Melanesia, Micronesia, as well as Easter Island and Hawaii. We performed a literature search using four international databases for articles published between January 1947 and June 2017. We further included grey literature available on the internet. We identified 148 studies describing leptospirosis epidemiology, but the number of studies varied significantly between PIs. No data were available from four PIs. Human leptospirosis has been reported from 13 PIs, with 63% of all studies conducted in Hawaii, French Polynesia and New Caledonia. Animal leptospirosis has been investigated in 19 PIs and from 14 host species, mainly pigs (18% of studies), cattle (16%) and dogs (11%). Only 13 studies provided information on both human and animal leptospirosis from the same location. Serology results were highly diverse in the region, both in humans and animals. Our study suggests that, as in other tropical regions, leptospirosis is widespread in the PIs while showing some epidemiological heterogeneity. Data are scarce or absent from many PIs. Rodents, cattle, pigs and dogs are all likely to be important carriers, but the relative importance of each animal species in human infection needs to be clarified. Epidemiological surveys with appropriate sampling design, pathogen typing and data analysis are needed to improve our understanding of transmission patterns and to develop effective intervention strategies.

Gene-Environment Interactions in Schizophrenia: Review of Epidemiological Findings and Future Directions

PubMed Central

van Os, Jim; Rutten, Bart PF; Poulton, Richie

2008-01-01

Concern is building about high rates of schizophrenia in large cities, and among immigrants, cannabis users, and traumatized individuals, some of which likely reflects the causal influence of environmental exposures. This, in combination with very slow progress in the area of molecular genetics, has generated interest in more complicated models of schizophrenia etiology that explicitly posit gene-environment interactions (EU-GEI. European Network of Schizophrenia Networks for the Study of Gene Environment Interactions. Schizophrenia aetiology: do gene-environment interactions hold the key? [published online ahead of print April 25, 2008] Schizophr Res; S0920-9964(08) 00170–9). Although findings of epidemiological gene-environment interaction (G × E) studies are suggestive of widespread gene-environment interactions in the etiology of schizophrenia, numerous challenges remain. For example, attempts to identify gene-environment interactions cannot be equated with molecular genetic studies with a few putative environmental variables “thrown in”: G × E is a multidisciplinary exercise involving epidemiology, psychology, psychiatry, neuroscience, neuroimaging, pharmacology, biostatistics, and genetics. Epidemiological G × E studies using indirect measures of genetic risk in genetically sensitive designs have the advantage that they are able to model the net, albeit nonspecific, genetic load. In studies using direct molecular measures of genetic variation, a hypothesis-driven approach postulating synergistic effects between genes and environment impacting on a final common pathway, such as “sensitization” of mesolimbic dopamine neurotransmission, while simplistic, may provide initial focus and protection against the numerous false-positive and false-negative results that these investigations engender. Experimental ecogenetic approaches with randomized assignment may help to overcome some of the limitations of observational studies and allow for the additional elucidation of underlying mechanisms using a combination of functional enviromics and functional genomics. PMID:18791076

10 CFR 602.5 - Epidemiology and Other Health Studies Financial Assistance Program.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 10 Energy 4 2013-01-01 2013-01-01 false Epidemiology and Other Health Studies Financial Assistance... AND OTHER HEALTH STUDIES FINANCIAL ASSISTANCE PROGRAM § 602.5 Epidemiology and Other Health Studies... toxic substances; (5) Epidemiology and other health studies relating to energy production, transmission...

10 CFR 602.5 - Epidemiology and Other Health Studies Financial Assistance Program.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 10 Energy 4 2014-01-01 2014-01-01 false Epidemiology and Other Health Studies Financial Assistance... AND OTHER HEALTH STUDIES FINANCIAL ASSISTANCE PROGRAM § 602.5 Epidemiology and Other Health Studies... toxic substances; (5) Epidemiology and other health studies relating to energy production, transmission...

10 CFR 602.5 - Epidemiology and Other Health Studies Financial Assistance Program.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 10 Energy 4 2012-01-01 2012-01-01 false Epidemiology and Other Health Studies Financial Assistance... AND OTHER HEALTH STUDIES FINANCIAL ASSISTANCE PROGRAM § 602.5 Epidemiology and Other Health Studies... toxic substances; (5) Epidemiology and other health studies relating to energy production, transmission...

10 CFR 602.5 - Epidemiology and Other Health Studies Financial Assistance Program.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 10 Energy 4 2011-01-01 2011-01-01 false Epidemiology and Other Health Studies Financial Assistance... AND OTHER HEALTH STUDIES FINANCIAL ASSISTANCE PROGRAM § 602.5 Epidemiology and Other Health Studies... toxic substances; (5) Epidemiology and other health studies relating to energy production, transmission...

Interactions among human behavior, social networks, and societal infrastructures: A Case Study in Computational Epidemiology

NASA Astrophysics Data System (ADS)

Barrett, Christopher L.; Bisset, Keith; Chen, Jiangzhuo; Eubank, Stephen; Lewis, Bryan; Kumar, V. S. Anil; Marathe, Madhav V.; Mortveit, Henning S.

Human behavior, social networks, and the civil infrastructures are closely intertwined. Understanding their co-evolution is critical for designing public policies and decision support for disaster planning. For example, human behaviors and day to day activities of individuals create dense social interactions that are characteristic of modern urban societies. These dense social networks provide a perfect fabric for fast, uncontrolled disease propagation. Conversely, people’s behavior in response to public policies and their perception of how the crisis is unfolding as a result of disease outbreak can dramatically alter the normally stable social interactions. Effective planning and response strategies must take these complicated interactions into account. In this chapter, we describe a computer simulation based approach to study these issues using public health and computational epidemiology as an illustrative example. We also formulate game-theoretic and stochastic optimization problems that capture many of the problems that we study empirically.

Cholera outbreak in Homa Bay County, Kenya, 2015.

PubMed

Githuku, Jane Njoki; Boru, Waqo Gufu; Hall, Casey Daniel; Gura, Zeinab; Oyugi, Elvis; Kishimba, Rogath Saika; Semali, Innocent; Farhat, Ghada Nadim; Mattie Park, Meeyoung

2017-01-01

Cholera is among the re-emerging diseases in Kenya. Beginning in December 2014, a persistent outbreak occurred involving 29 out of the 47 countries. Homa Bay County in Western Kenya was among the first counties to report cholera cases from January to April 2015. This case study is based on an outbreak investigation conducted by FELTP residents in Homa Bay County in February 2015. It simulates an outbreak investigation including laboratory confirmation, active case finding, descriptive epidemiology and implementation of control measures. This case study is designed for the training of basic level field epidemiology trainees or any other health care workers working in public health-related fields. It can be administered in 2-3 hours. Used as adjunct training material, the case study provides the trainees with competencies in investigating an outbreak in preparation for the actual real-life experience of such outbreaks.

The Study to Explore Early Development (SEED): A Multisite Epidemiologic Study of Autism by the Centers for Autism and Developmental Disabilities Research and Epidemiology (CADDRE) Network

PubMed Central

Schendel, Diana; DiGuiseppi, Carolyn; Croen, Lisa; Fallin, M Danielle; Reed, Philip L.; Schieve, Laura; Wiggins, Lisa; Daniels, Julie; Grether, Judith; Levy, Susan; Miller, Lisa; Newschaffer, Craig; Pinto-Martin, Jennifer; Robinson, Cordelia; Windham, Gayle; Alexander, Aimee; Aylsworth, Arthur; Bernal, Pilar; Bonner, Joseph D.; Blaskey, Lisa; Bradley, Chyrise; Collins, Jack; Ferretti, Casara; Farzadegan, Homayoon; Giarelli, Ellen; Harvey, Marques; Hepburn, Susan; Herr, Matthew; Kaparich, Kristina; Landa, Rebecca; Lee, Li-Ching; Levenseller, Brooke; Meyerer, Stacey; Rahbar, Mohammad H.; Ratchford, Andria; Reynolds, Ann; Rosenberg, Steve; Rusyniak, Julie; Shapira, Stuart K.; Smith, Karen; Souders, Margaret; AaronThompson, Patrick; Young, Lisa; Yeargin-Allsopp, Marshalyn

2015-01-01

The Study to Explore Early Development (SEED), a multisite investigation addressing knowledge gaps in autism phenotype and etiology, aims to: (1) characterize the autism behavioral phenotype and associated developmental, medical, and behavioral conditions and (2) investigate genetic and environmental risks with emphasis on immunologic, hormonal, gastrointestinal, and sociodemographic characteristics. SEED uses a case–control design with population-based ascertainment of children aged 2–5 years with an autism spectrum disorder (ASD) and children in two control groups—one from the general population and one with non-ASD developmental problems. Data from parent-completed questionnaires, interviews, clinical evaluations, biospecimen sampling, and medical record abstraction focus on the prenatal and early postnatal periods. SEED is a valuable resource for testing hypotheses regarding ASD characteristics and causes. PMID:22350336

The legacy of war: an epidemiological study of cluster weapon and land mine accidents in Quang Tri Province, Vietnam.

PubMed

Phung, Tran Kim; Le, Viet; Husum, Hans

2012-07-01

The study examines the epidemiology of cluster weapon and land mine accidents in Quang Tri Province since the end of the Vietnam War. The province is located just south of the demarcation line and was the province most affected during the war. In 2009, a cross sectional household study was conducted in all nine districts of the province. During the study period of 1975-2009, 7,030 persons in the study area were exposed to unexploded ordnances (UXO) or land mine accidents, or 1.1% of the provincial population. There were 2,620 fatalities and 4,410 accident survivors. The study documents that the main problem is cluster weapons and other unexploded ordnances; only 4.3% of casualties were caused by land mines. The legacy of the war affects poor people the most; the accident rate was highest among villagers living in mountainous areas, ethnic minorities, and low-income families. The most common activities leading to the accidents were farming (38.6%), collecting scrap metal (11.2%), and herding of cattle (8.3%). The study documents that the people of the Quang Tri Province until this day have suffered heavily due to the legacy of war. Mine risk education programs should account for the epidemiological findings when future accident prevention programs are designed to target high-risk areas and activities.

Correlates of Cortisol in Human Hair: Implications for Epidemiologic Studies on Health Effects of Chronic Stress

PubMed Central

Wosu, Adaeze C.; Valdimarsdóttir, Unnur; Shields, Alexandra E.; Williams, David R.; Williams, Michelle A.

2013-01-01

Assessment of cortisol concentrations in hair is one of the latest innovations for measuring long-term cortisol exposure. We performed a systematic review of correlates of cortisol in human hair to inform the design, analysis and interpretation of future epidemiologic studies. Relevant publications were identified through electronic searches on PubMed, WorldCat, and Web of Science using keywords, “cortisol” “hair” “confounders” “chronic” “stress” and “correlates.” Thirty-nine studies were included in this review. Notwithstanding scarce data and some inconsistencies, investigators have found hair cortisol concentrations to be associated with stress-related psychiatric symptoms and disorders (e.g., PTSD), medical conditions indicating chronic activation of the hypothalamic-pituitary-adrenal axis (e.g., Cushing´s syndrome) and other life situations associated with elevated risk of chronic stress (e.g., shiftwork). Results from some studies suggest that physical activity, adiposity, and substance abuse may be correlates of hair cortisol concentrations. In contrast to measures of short-term cortisol release (saliva, blood, and urine), cigarette smoking and use of oral contraceptives appear to not be associated with hair cortisol concentrations. Studies of pregnant women indicate increased hair cortisol concentrations across successive trimesters. The study of hair cortisol presents a unique opportunity to assess chronic alterations in cortisol concentrations in epidemiologic studies. PMID:24184029

Correlates of cortisol in human hair: implications for epidemiologic studies on health effects of chronic stress.

PubMed

Wosu, Adaeze C; Valdimarsdóttir, Unnur; Shields, Alexandra E; Williams, David R; Williams, Michelle A

2013-12-01

Assessment of cortisol concentrations in hair is one of the latest innovations for measuring long-term cortisol exposure. We performed a systematic review of correlates of cortisol in human hair to inform the design, analysis, and interpretation of future epidemiologic studies. Relevant publications were identified through electronic searches on PubMed, WorldCat, and Web of Science using keywords, "cortisol," "hair," "confounders," "chronic," "stress," and "correlates." Thirty-nine studies were included in this review. Notwithstanding scarce data and some inconsistencies, investigators have found hair cortisol concentrations to be associated with stress-related psychiatric symptoms and disorders (e.g., post-traumatic stress disorder), medical conditions indicating chronic activation of the hypothalamic-pituitary-adrenal axis (e.g., Cushing's syndrome), and other life situations associated with elevated risk of chronic stress (e.g., shiftwork). Results from some studies suggest that physical activity, adiposity, and substance abuse may be correlates of hair cortisol concentrations. In contrast to measures of short-term cortisol release (saliva, blood, and urine), cigarette smoking and use of oral contraceptives appear not to be associated with hair cortisol concentrations. Studies of pregnant women indicate increased hair cortisol concentrations across successive trimesters. The study of hair cortisol presents a unique opportunity to assess chronic alterations in cortisol concentrations in epidemiologic studies. Copyright © 2013 Elsevier Inc. All rights reserved.

High prevalence of toxoplasmosis in cats from Egypt: isolation of viable Toxoplasma Gondii, tissue distribution, and isolate designation

USDA-ARS?s Scientific Manuscript database

Cats are important in the epidemiology of Toxoplasma gondii because they are the only hosts that excrete environmentally resistant oocysts in feces. In the present study, 158 feral cats from Giza, Egypt were examined for T. gondii infection. Antibodies to T. gondii were found in 97.4% with modified ...

The Home Inventory of Dangers and Safety Precautions--2: Addressing Critical Needs for Prescriptive Assessment Devices in Child Maltreatment and in Healthcare.

ERIC Educational Resources Information Center

Tymchuk, Alexander J.; Lang, Cathy M.; Doylniuk, Chrystina A.; Berney-Ficklin, Karen; Spitz, Rebecca

1999-01-01

Describes a study involving 29 low-income parents with learning difficulties that validated a prescriptive home-danger and safety-precaution instrument containing 14 epidemiological categories to be used in the design and evaluation of family-tailored injury prevention and safety interventions. (Author/CR)

The Childhood Asperger Syndrome Test (CAST): Test-Retest Reliability in a High Scoring Sample

ERIC Educational Resources Information Center

Allison, Carrie; Williams, Jo; Scott, Fiona; Stott, Carol; Bolton, Patrick; Baron-Cohen, Simon; Brayne, Carol

2007-01-01

The Childhood Asperger Syndrome Test (CAST) is a 37-item parental self-completion questionnaire designed to screen for high-functioning autism spectrum conditions in epidemiological research. The CAST has previously demonstrated good accuracy for use as a screening test, with high sensitivity in studies with primary school aged children in…

Random amplified polymorphic DNA PCR in the teaching of molecular epidemiology.

PubMed

Reinoso, Elina B; Bettera, Susana G

2016-07-08

In this article, we describe a basic practical laboratory designed for fifth-year undergraduate students of Microbiology as part of the Epidemiology course. This practice provides the students with the tools for molecular epidemiological analysis of pathogenic microorganisms using a rapid and simple PCR technique. The aim of this work was to assay RAPD-PCR technique in order to infer possible epidemiological relationships. The activity gives students an appreciation of the value of applying a simple molecular biological method as RAPD-PCR to a discipline-specific question. It comprises a three-session laboratory module to genetically assay DNAs from strains isolated from a food outbreak. © 2016 by The International Union of Biochemistry and Molecular Biology, 44(4):391-396, 2016. © 2016 The International Union of Biochemistry and Molecular Biology.

The incidence and prevalence of ankle sprain injury: a systematic review and meta-analysis of prospective epidemiological studies.

PubMed

Doherty, Cailbhe; Delahunt, Eamonn; Caulfield, Brian; Hertel, Jay; Ryan, John; Bleakley, Chris

2014-01-01

Ankle sprain is one of the most common musculoskeletal injuries, yet a contemporary review and meta-analysis of prospective epidemiological studies investigating ankle sprain does not exist. Our aim is to provide an up-to-date account of the incidence rate and prevalence period of ankle sprain injury unlimited by timeframe or context activity. We conducted a systematic review and meta-analyses of English articles using relevant computerised databases. Search terms included Medical Search Headings for the ankle joint, injury and epidemiology. The following inclusion criteria were used: the study must report epidemiology findings of injuries sustained in an observed sample; the study must report ankle sprain injury with either incidence rate or prevalence period among the surveyed sample, or provide sufficient data from which these figures could be calculated; the study design must be prospective. Independent extraction of articles was performed by two authors using pre-determined data fields. One-hundred and eighty-one prospective epidemiology studies from 144 separate papers were included. The average rating of all the included studies was 6.67/11, based on an adapted version of the STROBE (STrengthening the Reporting of OBservational studies in Epidemiology) guidelines for rating observational studies. 116 studies were considered high quality and 65 were considered low quality. The main findings of the meta-analysis demonstrated a higher incidence of ankle sprain in females compared with males (13.6 vs 6.94 per 1,000 exposures), in children compared with adolescents (2.85 vs 1.94 per 1,000 exposures) and adolescents compared with adults (1.94 vs 0.72 per 1,000 exposures). The sport category with the highest incidence of ankle sprain was indoor/court sports, with a cumulative incidence rate of 7 per 1,000 exposures or 1.37 per 1,000 athlete exposures and 4.9 per 1,000 h. Low-quality studies tended to underestimate the incidence of ankle sprain when compared with high-quality studies (0.54 vs 11.55 per 1,000 exposures). Ankle sprain prevalence period estimates were similar across sub-groups. Lateral ankle sprain was the most commonly observed type of ankle sprain. Females were at a higher risk of sustaining an ankle sprain compared with males and children compared with adolescents and adults, with indoor and court sports the highest risk activity. Studies at a greater risk of bias were more likely to underestimate the risk of ankle sprain. Participants were at a significantly higher risk of sustaining a lateral ankle sprain compared with syndesmotic and medial ankle sprains.

[Which definition and taxonomy of incident to use for a French reporting system in primary care settings?].

PubMed

Keriel-Gascou, M; Brami, J; Chanelière, M; Haeringer-Cholet, A; Larrieu, C; Villebrun, F; Robert, T; Michel, P

2014-02-01

There is no widely accepted definition of incident for primary care doctors in France and no taxonomic classification system for epidemiological use. In preparation for a future epidemiological study on primary care incidents in France (the ESPRIT study), this work was designed to identify the definitions and taxonomic classifications used internationally along with the usual methods and results in terms of frequency in the literature. The goal was to determine a French definition and taxonomy. Systematic review of the literature and consensus methods. An exhaustive search of epidemiological surveys was performed. A structured grid was used. After having identified the definitions used in the literature, a definition was chosen using the focus groups method. Taxonomies identified in the literature were classified by relationship, architecture, code number, and number of studies published. Subsequently, a consensus among experts, who independently tested these taxonomies on six incidents, was reached for choosing the most appropriate for epidemiological data collection (little information on a large number of cases). Twenty-four papers reporting 17 studies were selected among 139 articles. Five definitions and eight taxonomies were found. The chosen definition of incident was based on the WHO definition "A patient safety incident is an event or circumstance that could have resulted, or did result, in harm to a patient, and whose wish it is not repeated again". The test of incidents resulted in the choice of the TAPS version of the International Taxonomy of Medical Error in Primary Care for a reproducible and internationally recognized codification and the tempos method for its current use in French general practice. The definitions, taxonomies, data collection characteristics and frequency of incidents results in the international literature on incidents in primary care are key components for the preparation of an epidemiological survey on incidents in primary care. Copyright © 2014. Published by Elsevier Masson SAS.

Informed consent, and an ethico-legal framework for paediatric observational research and biobanking: the experience of an Italian birth cohort study.

PubMed

Toccaceli, Virgilia; Serino, Laura; Stazi, Maria Antonietta

2014-12-01

Birth cohort studies are important tools for life-course epidemiology, given the spectrum of the environmental, behavioural, and genetic factors that should be considered when making judgements on human health. Biobanks are valuable components of studies designed to investigate the genetic variability of diseases and improve phenotypic characterisation. In studies involving vulnerable populations and biobanks, it is essential to provide ethical reasoning and analyse the legal requirements. We describe the processes and the tools used in the iterative design of an appropriate informed consent model and the ethico-legal framework of the Piccolipiù study. The Piccolipiù study is a prospective population-based study funded by the Italian Ministry of Health that intends to enrol 3,000 newborns and their mothers in five Italian cities, and to store biological samples for future use. To realise these objectives, we performed a thorough evaluation of the literature, of national and international guidelines, and of the impact of the Italian legal requirements for research biobanking. Discussions among stakeholders facilitated the design of the informed consent and the ethico-legal framework. Several topics are addressed, including the suitability of a broad informed consent for paediatric biobanks, infant vulnerability, access to and sharing of data, and the disclosure of individual's genetic results. Discussion of the ethical and legal procedures adopted in epidemiological biobanking might be a fruitful ground for comparison both at the national level, where standardization and homogeneity are lacking, and at the international level, where different regulatory issues are often in the background and might hamper research biobanks networking.

Community participation in disease control.

PubMed

Bermejo, A; Bekui, A

1993-05-01

The main determinants of community participation in disease control programmes are identified and a framework with eleven variables is developed. Attention is drawn to the political background, community characteristics, the managerial capacity of the provider and the epidemiology of the disease. The framework is designed to guide health professionals in the systematic assessment and monitoring of participation in disease control programmes. Analysis of the Ghanaian Guinea Worm Eradication Programme and the Nicaraguan Tuberculosis Control Programme are presented as case studies. They show that political support does not guarantee community participation in disease control programmes and stress the importance of other determinants such as commitment to PHC, intersectoral coordination, the project approach and human resources. The relevance of the epidemiology of the disease in determining what degree of community participation will be most effective is highlighted by the case studies.

Retrospective studies of operating problems in air transport

NASA Technical Reports Server (NTRS)

Billings, C. E.; Lauber, J. K.; Cooper, G. E.; Ruffell-Smith, H. P.

1976-01-01

An epidemiological model for the study of human errors in aviation is presented. In this approach, retrospective data are used as the basis for formulation of hypotheses as to system factors which may have contributed to such errors. Prospective experimental studies of aviation operations are also required in order to prove or disprove the hypotheses, and to evaluate the effectiveness of intervention techniques designed to solve operational problems in the aviation system.

Optimising and communicating options for the control of invasive plant disease when there is epidemiological uncertainty.

PubMed

Cunniffe, Nik J; Stutt, Richard O J H; DeSimone, R Erik; Gottwald, Tim R; Gilligan, Christopher A

2015-04-01

Although local eradication is routinely attempted following introduction of disease into a new region, failure is commonplace. Epidemiological principles governing the design of successful control are not well-understood. We analyse factors underlying the effectiveness of reactive eradication of localised outbreaks of invading plant disease, using citrus canker in Florida as a case study, although our results are largely generic, and apply to other plant pathogens (as we show via our second case study, citrus greening). We demonstrate how to optimise control via removal of hosts surrounding detected infection (i.e. localised culling) using a spatially-explicit, stochastic epidemiological model. We show how to define optimal culling strategies that take account of stochasticity in disease spread, and how the effectiveness of disease control depends on epidemiological parameters determining pathogen infectivity, symptom emergence and spread, the initial level of infection, and the logistics and implementation of detection and control. We also consider how optimal culling strategies are conditioned on the levels of risk acceptance/aversion of decision makers, and show how to extend the analyses to account for potential larger-scale impacts of a small-scale outbreak. Control of local outbreaks by culling can be very effective, particularly when started quickly, but the optimum strategy and its performance are strongly dependent on epidemiological parameters (particularly those controlling dispersal and the extent of any cryptic infection, i.e. infectious hosts prior to symptoms), the logistics of detection and control, and the level of local and global risk that is deemed to be acceptable. A version of the model we developed to illustrate our methodology and results to an audience of stakeholders, including policy makers, regulators and growers, is available online as an interactive, user-friendly interface at http://www.webidemics.com/. This version of our model allows the complex epidemiological principles that underlie our results to be communicated to a non-specialist audience.

Paper vs. electrons. Epidemiologic publishing in a changing world.

PubMed

Rothenberg; Frank; Fitzmaurice

2000-10-01

PURPOSE: To present the parallel histories of epidemiologic and electronic publishing and consider positive and negative factors that might affect their amalgam.METHODS: We performed a quantitative assessment of the arc of epidemiologic publication from 1966-1999, using major self-designated epidemiologic journals as a sample, and of scholarly electronic publication from 1991-1997, based on current literature review. We use an online, paperless journal as a case study, and review selected information-technology opinion in the area.RESULTS: By traditional standards, growth in epidemiologic publication has been considerable, with the addition of six new journals since 1966. In contrast, scholarly electronic publication for the period 1991-1997 grew from 27 to 2459 journals (not all exclusively online). Positive features of electronic publishing include flexibility, shortened time to publication, freedom from fixed publication date, diversity in presentation, and instant linkage to relevant material. A case study of a new online journal illustrates the substantive power of the medium. Negative factors include restriction (or unrestricted expansion) of the audience, the potential for hasty peer review, pitfalls in establishing credibility, an emphasis on style over content, technologic dependence, and additions to the information explosion. Relative cost and archiving are still debated. In assessing the pros and cons, it is important to distinguish electronic mechanisms that facilitate publication from electronic publishing, and to appreciate the difference between moving an existing journal to the electronic medium, and creating a new online journal.CONCLUSIONS: The movement from print to internet is probably inexorable, but a headlong rush may be ill-advised. Several models for dual publishing now exist, with the expectation that many, including the journals that serve epidemiology, will do so. The ultimate configuration is difficult to predict, but likely to be shaped in large measure by market forces, technologic advances and to a lesser extent, by habit and aesthetics.

Optimising and Communicating Options for the Control of Invasive Plant Disease When There Is Epidemiological Uncertainty

PubMed Central

Cunniffe, Nik J.; Stutt, Richard O. J. H.; DeSimone, R. Erik; Gottwald, Tim R.; Gilligan, Christopher A.

2015-01-01

Although local eradication is routinely attempted following introduction of disease into a new region, failure is commonplace. Epidemiological principles governing the design of successful control are not well-understood. We analyse factors underlying the effectiveness of reactive eradication of localised outbreaks of invading plant disease, using citrus canker in Florida as a case study, although our results are largely generic, and apply to other plant pathogens (as we show via our second case study, citrus greening). We demonstrate how to optimise control via removal of hosts surrounding detected infection (i.e. localised culling) using a spatially-explicit, stochastic epidemiological model. We show how to define optimal culling strategies that take account of stochasticity in disease spread, and how the effectiveness of disease control depends on epidemiological parameters determining pathogen infectivity, symptom emergence and spread, the initial level of infection, and the logistics and implementation of detection and control. We also consider how optimal culling strategies are conditioned on the levels of risk acceptance/aversion of decision makers, and show how to extend the analyses to account for potential larger-scale impacts of a small-scale outbreak. Control of local outbreaks by culling can be very effective, particularly when started quickly, but the optimum strategy and its performance are strongly dependent on epidemiological parameters (particularly those controlling dispersal and the extent of any cryptic infection, i.e. infectious hosts prior to symptoms), the logistics of detection and control, and the level of local and global risk that is deemed to be acceptable. A version of the model we developed to illustrate our methodology and results to an audience of stakeholders, including policy makers, regulators and growers, is available online as an interactive, user-friendly interface at http://www.webidemics.com/. This version of our model allows the complex epidemiological principles that underlie our results to be communicated to a non-specialist audience. PMID:25874622

Assessing health impacts in complex eco-epidemiological settings in the humid tropics: Modular baseline health surveys

DOE Office of Scientific and Technical Information (OSTI.GOV)

Winkler, Mirko S., E-mail: mirko.winkler@unibas.ch; University of Basel, P.O. Box, CH-4003 Basel; Divall, Mark J., E-mail: mdivall@shapeconsulting.org

2012-02-15

The quantitative assessment of health impacts has been identified as a crucial feature for realising the full potential of health impact assessment (HIA). In settings where demographic and health data are notoriously scarce, but there is a broad range of ascertainable ecological, environmental, epidemiological and socioeconomic information, a diverse toolkit of data collection strategies becomes relevant for the mainly small-area impacts of interest. We present a modular, cross-sectional baseline health survey study design, which has been developed for HIA of industrial development projects in the humid tropics. The modular nature of our toolkit allows our methodology to be readily adaptedmore » to the prevailing eco-epidemiological characteristics of a given project setting. Central to our design is a broad set of key performance indicators, covering a multiplicity of health outcomes and determinants at different levels and scales. We present experience and key findings from our modular baseline health survey methodology employed in 14 selected sentinel sites within an iron ore mining project in the Republic of Guinea. We argue that our methodology is a generic example of rapid evidence assembly in difficult-to-reach localities, where improvement of the predictive validity of the assessment and establishment of a benchmark for longitudinal monitoring of project impacts and mitigation efforts is needed.« less

Quality Assessment of Studies Published in Open Access and Subscription Journals: Results of a Systematic Evaluation.

PubMed

Pastorino, Roberta; Milovanovic, Sonja; Stojanovic, Jovana; Efremov, Ljupcho; Amore, Rosarita; Boccia, Stefania

2016-01-01

Along with the proliferation of Open Access (OA) publishing, the interest for comparing the scientific quality of studies published in OA journals versus subscription journals has also increased. With our study we aimed to compare the methodological quality and the quality of reporting of primary epidemiological studies and systematic reviews and meta-analyses published in OA and non-OA journals. In order to identify the studies to appraise, we listed all OA and non-OA journals which published in 2013 at least one primary epidemiologic study (case-control or cohort study design), and at least one systematic review or meta-analysis in the field of oncology. For the appraisal, we picked up the first studies published in 2013 with case-control or cohort study design from OA journals (Group A; n = 12), and in the same time period from non-OA journals (Group B; n = 26); the first systematic reviews and meta-analyses published in 2013 from OA journals (Group C; n = 15), and in the same time period from non-OA journals (Group D; n = 32). We evaluated the methodological quality of studies by assessing the compliance of case-control and cohort studies to Newcastle and Ottawa Scale (NOS) scale, and the compliance of systematic reviews and meta-analyses to Assessment of Multiple Systematic Reviews (AMSTAR) scale. The quality of reporting was assessed considering the adherence of case-control and cohort studies to STrengthening the Reporting of OBservational studies in Epidemiology (STROBE) checklist, and the adherence of systematic reviews and meta-analyses to Preferred Reporting Items for Systematic reviews and Meta-Analysis (PRISMA) checklist. Among case-control and cohort studies published in OA and non-OA journals, we did not observe significant differences in the median value of NOS score (Group A: 7 (IQR 7-8) versus Group B: 8 (7-9); p = 0.5) and in the adherence to STROBE checklist (Group A, 75% versus Group B, 80%; p = 0.1). The results did not change after adjustment for impact factor. The compliance with AMSTAR and adherence to PRISMA checklist were comparable between systematic reviews and meta-analyses published in OA and non-OA journals (Group C, 46.0% versus Group D, 55.0%; p = 0.06), (Group C, 72.0% versus Group D, 76.0%; p = 0.1), respectively). The epidemiological studies published in OA journals in the field of oncology approach the same methodological quality and quality of reporting as studies published in non-OA journals.

Quality Assessment of Studies Published in Open Access and Subscription Journals: Results of a Systematic Evaluation

PubMed Central

Pastorino, Roberta; Milovanovic, Sonja; Stojanovic, Jovana; Efremov, Ljupcho; Amore, Rosarita; Boccia, Stefania

2016-01-01

Introduction Along with the proliferation of Open Access (OA) publishing, the interest for comparing the scientific quality of studies published in OA journals versus subscription journals has also increased. With our study we aimed to compare the methodological quality and the quality of reporting of primary epidemiological studies and systematic reviews and meta-analyses published in OA and non-OA journals. Methods In order to identify the studies to appraise, we listed all OA and non-OA journals which published in 2013 at least one primary epidemiologic study (case-control or cohort study design), and at least one systematic review or meta-analysis in the field of oncology. For the appraisal, we picked up the first studies published in 2013 with case-control or cohort study design from OA journals (Group A; n = 12), and in the same time period from non-OA journals (Group B; n = 26); the first systematic reviews and meta-analyses published in 2013 from OA journals (Group C; n = 15), and in the same time period from non-OA journals (Group D; n = 32). We evaluated the methodological quality of studies by assessing the compliance of case-control and cohort studies to Newcastle and Ottawa Scale (NOS) scale, and the compliance of systematic reviews and meta-analyses to Assessment of Multiple Systematic Reviews (AMSTAR) scale. The quality of reporting was assessed considering the adherence of case-control and cohort studies to STrengthening the Reporting of OBservational studies in Epidemiology (STROBE) checklist, and the adherence of systematic reviews and meta-analyses to Preferred Reporting Items for Systematic reviews and Meta-Analysis (PRISMA) checklist. Results Among case-control and cohort studies published in OA and non-OA journals, we did not observe significant differences in the median value of NOS score (Group A: 7 (IQR 7–8) versus Group B: 8 (7–9); p = 0.5) and in the adherence to STROBE checklist (Group A, 75% versus Group B, 80%; p = 0.1). The results did not change after adjustment for impact factor. The compliance with AMSTAR and adherence to PRISMA checklist were comparable between systematic reviews and meta-analyses published in OA and non-OA journals (Group C, 46.0% versus Group D, 55.0%; p = 0.06), (Group C, 72.0% versus Group D, 76.0%; p = 0.1), respectively). Conclusion The epidemiological studies published in OA journals in the field of oncology approach the same methodological quality and quality of reporting as studies published in non-OA journals. PMID:27167982

[The case-case-time-control study design].

PubMed

Wang, Jing; Zhuo, Lin; Zhan, Siyan

2014-12-01

Although the 'self-matched case-only studies' (such as the case-cross-over or self-controlled case-series method) can control the time-invariant confounders (measured or unmeasured) through design of the study, however, they can not control those confounders that vary with time. A bidirectional case-crossover design can be used to adjust the exposure-time trends. In the areas of pharmaco-epidemiology, illness often influence the future use of medications, making a bidirectional study design problematic. Suissa's case-time-control design combines the case-crossover and the case-control design which could adjust for exposure-trend bias, but the control group may reintroduce selection bias, if the matching does not go well. We propose a "case-case-time-control" design which is an extension of the case-time-control design. However, rather than using a sample of external controls, we choose those future cases as controls for current cases to counter the bias that arising from temporal trends caused by exposure to the target of interest. In the end of this article we will discuss the strength and limitations of this design based on an applied example.

A Pilot Prospective Study of Fetomaternal Hemorrhage Identified by Anemia in Asymptomatic Neonates

PubMed Central

Stroustrup, Annemarie; Plafkin, Callie

2016-01-01

Background Fetomaternal hemorrhage (FMH) is a poorly understood condition in which fetal erythrocytes transfer to the maternal circulation via a faulty placental barrier. Little is known about the true incidence, epidemiology, or pathophysiology of FMH in the general pregnant population as existing studies are based on retrospective cohorts and manifest diagnosis and selection bias. Objective To evaluate the practicability of a prospective study of fetomaternal hemorrhage in the general population based on antepartum maternal blood testing and neonatal anemia. Study Design Prospective cohort study. Result Nineteen pregnant women were enrolled prior to the term delivery of twenty well infants. Five neonates were unexpectedly anemic on first postnatal testing. Antenatal maternal blood samples associated with 2 of 5 anemic newborns had positive Kleihauer-Betke testing while no newborn with a normal postnatal blood count had an associated abnormal Kleihauer-Betke test. Conclusion Clinically significant FMH may be more common than previously thought. Prospective epidemiological study of FMH is feasible. PMID:26765555

ADHD in the Arab World: A Review of Epidemiologic Studies

ERIC Educational Resources Information Center

Farah, Lynn G.; Fayyad, John A.; Eapen, Valsamma; Cassir,Youmna; Salamoun, Mariana M.; Tabet, Caroline C.; Mneimneh, Zeina N.; Karam, Elie G.

2009-01-01

Objective: Epidemiological studies on psychiatric disorders are quite rare in the Arab World. This article reviews epidemiological studies on ADHD in all the Arab countries. Method: All epidemiological studies on ADHD conducted from 1966 through th present were reviewed. Samples were drawn from the general community, primary care clinical…

Injury epidemiology after the 2001 Gujarat earthquake in India: a retrospective analysis of injuries treated at a rural hospital in the Kutch district immediately after the disaster

PubMed Central

Phalkey, Revati; Reinhardt, Jan D.; Marx, Michael

2011-01-01

Background The number of injured far exceeds those dead and the average injury to mortality ratio in earthquakes stands at 3:1. Immediate effective medical response significantly influences injury outcomes and thus the overall health impact of earthquakes. Inadequate or mismanagement of injuries may lead to disabilities. The lack of precise data from immediate aftermath is seen as a remarkable weak point in disaster epidemiology and warrants evidence generation. Objective To analyze the epidemiology of injuries and the treatment imparted at a secondary rural hospital in the Kutch district, Gujarat, India following the January 26, 2001 earthquake. Design/Methods Discharge reports of patients admitted to the hospital over 10 weeks were analyzed retrospectively for earthquake-related injuries. Results Orthopedic injuries, (particularly fractures of the lower limbs) were predominant and serious injuries like head, chest, abdominal, and crush syndrome were minimal. Wound infections were reported in almost 20% of the admitted cases. Surgical procedures were more common than conservative treatment. The most frequently performed surgical procedures were open reduction with internal fixation and cleaning and debridement of contaminated wounds. Four secondary deaths and 102 transfers to tertiary care due to complications were reported. Conclusion The injury epidemiology reported in this study is in general agreement with most other studies reporting injury epidemiology except higher incidence of distal orthopedic injuries particularly to the lower extremities. We also found that young males were more prone to sustaining injuries. These results warrant further research. Inconsistent data reporting procedures against the backdrop of inherent disaster data incompleteness calls for urgent standardization of reporting earthquake injuries for evidence-based response policy planning. PMID:21799668

Molecular Infectious Disease Epidemiology: Survival Analysis and Algorithms Linking Phylogenies to Transmission Trees

PubMed Central

Kenah, Eben; Britton, Tom; Halloran, M. Elizabeth; Longini, Ira M.

2016-01-01

Recent work has attempted to use whole-genome sequence data from pathogens to reconstruct the transmission trees linking infectors and infectees in outbreaks. However, transmission trees from one outbreak do not generalize to future outbreaks. Reconstruction of transmission trees is most useful to public health if it leads to generalizable scientific insights about disease transmission. In a survival analysis framework, estimation of transmission parameters is based on sums or averages over the possible transmission trees. A phylogeny can increase the precision of these estimates by providing partial information about who infected whom. The leaves of the phylogeny represent sampled pathogens, which have known hosts. The interior nodes represent common ancestors of sampled pathogens, which have unknown hosts. Starting from assumptions about disease biology and epidemiologic study design, we prove that there is a one-to-one correspondence between the possible assignments of interior node hosts and the transmission trees simultaneously consistent with the phylogeny and the epidemiologic data on person, place, and time. We develop algorithms to enumerate these transmission trees and show these can be used to calculate likelihoods that incorporate both epidemiologic data and a phylogeny. A simulation study confirms that this leads to more efficient estimates of hazard ratios for infectiousness and baseline hazards of infectious contact, and we use these methods to analyze data from a foot-and-mouth disease virus outbreak in the United Kingdom in 2001. These results demonstrate the importance of data on individuals who escape infection, which is often overlooked. The combination of survival analysis and algorithms linking phylogenies to transmission trees is a rigorous but flexible statistical foundation for molecular infectious disease epidemiology. PMID:27070316

Operational evaluation of the RLINE dispersion model for studies of traffic-related air pollutants

NASA Astrophysics Data System (ADS)

Milando, Chad W.; Batterman, Stuart A.

2018-06-01

Exposure to traffic-related air pollutants (TRAP) remains a key public health issue, and improved exposure measures are needed to support health impact and epidemiologic studies and inform regulatory responses. The recently developed Research LINE source model (RLINE), a Gaussian line source dispersion model, has been used in several epidemiologic studies of TRAP exposure, but evaluations of RLINE's performance in such applications have been limited. This study provides an operational evaluation of RLINE in which predictions of NOx, CO and PM2.5 are compared to observations at air quality monitoring stations located near high traffic roads in Detroit, MI. For CO and NOx, model performance was best at sites close to major roads, during downwind conditions, during weekdays, and during certain seasons. For PM2.5, the ability to discern local and particularly the traffic-related portion was limited, a result of high background levels, the sparseness of the monitoring network, and large uncertainties for certain processes (e.g., formation of secondary aerosols) and non-mobile sources (e.g., area, fugitive). Overall, RLINE's performance in near-road environments suggests its usefulness for estimating spatially- and temporally-resolved exposures. The study highlights considerations relevant to health impact and epidemiologic applications, including the importance of selecting appropriate pollutants, using appropriate monitoring approaches, considering prevailing wind directions during study design, and accounting for uncertainty.

An epidemiologic review of marijuana and cancer: an update

PubMed Central

Huang, Yu-Hui Jenny; Zhang, Zuo-Feng; Tashkin, Donald P.; Feng, Bingjian; Straif, Kurt; Hashibe, Mia

2014-01-01

Marijuana use is legal in two states and additional states are considering legalization. Approximately 18 million Americans are current marijuana users. There is currently no consensus on whether marijuana use is associated with cancer risk. Our objective is to review the epidemiologic studies on this possible association. We identified 34 epidemiologic studies on upper aerodigestive tract cancers (n=11), lung cancer (n=6), testicular cancer (n=3), childhood cancers (n=6), all cancers (n=1), anal cancer (n=1), penile cancer (n=1), non-Hodgkin's lymphoma (n=2), malignant primary gliomas(n=1), bladder cancer (n=1), and Kaposi's sarcoma (n=1). Studies on head and neck cancer reported increased and decreased risks, possibly because there is no association, or because risks differ by HPV status or geographic differences. The lung cancer studies largely appear not to support an association with marijuana use, possibly because of the smaller amounts of marijuana regularly smoked compared to tobacco. Three testicular cancer case-control studies reported increased risks with marijuana use (summary odds ratios 1.56 (95%CI=1.09-2.23) for higher frequency; 1.50 (95%=1.08-2.09) for ≥10 years). For other cancer sites, there is still insufficient data to make any conclusions. Considering that marijuana use may change due to legalization, well-designed studies on marijuana use and cancer are warranted. PMID:25587109

Vitamin D, calcium, and breast cancer risk: a review.

PubMed

Cui, Yan; Rohan, Thomas E

2006-08-01

Vitamin D and calcium are metabolically interrelated and highly correlated dietary factors. Experimental studies have shown their anticarcinogenic effects due to their participation in regulating cell proliferation, differentiation, and apoptosis in normal and malignant breast cells. Given the emerging interest in their potential roles in the etiology of breast cancer, we review the current epidemiologic literature on dietary and/or supplemental intakes of vitamin D, endogenous circulating levels of vitamin D, and dietary and/or supplemental intakes of calcium in relation to breast cancer risk. To place these studies in context, we also provide a brief review of other supporting epidemiologic evidence. Despite inconsistent results from the epidemiologic studies, several lines of evidence suggest that vitamin D and calcium may be involved in the development of breast cancer. Specifically, (a) there is some epidemiologic evidence for inverse associations between vitamin D and calcium intakes and breast cancer; (b) serum, plasma, and/or blood levels of vitamin D metabolites have been inversely associated with breast cancer risk in some studies; (c) high sunlight exposure, presumably reflecting vitamin D synthesis in the skin, has been associated with a reduced risk of breast cancer; (d) vitamin D and calcium intakes have been inversely related to breast density, an intermediate end point for breast cancer; (e) calcium has been associated with a reduced risk of benign proliferative epithelial disorders of the breast, putative precursors of breast cancer; and (f) certain polymorphisms of the vitamin D receptor might modify breast cancer susceptibility. To further confirm the potential protective effects of calcium and vitamin D on breast cancer, well-designed cohort studies and clinical trials are warranted.

Development and application of Human Genome Epidemiology

NASA Astrophysics Data System (ADS)

Xu, Jingwen

2017-12-01

Epidemiology is a science that studies distribution of diseases and health in population and its influencing factors, it also studies how to prevent and cure disease and promote health strategies and measures. Epidemiology has developed rapidly in recent years and it is an intercross subject with various other disciplines to form a series of branch disciplines such as Genetic epidemiology, molecular epidemiology, drug epidemiology and tumor epidemiology. With the implementation and completion of Human Genome Project (HGP), Human Genome Epidemiology (HuGE) has emerged at this historic moment. In this review, the development of Human Genome Epidemiology, research content, the construction and structure of relevant network, research standards, as well as the existing results and problems are briefly outlined.

Snippets From the Past: Is Flint, Michigan, the Birthplace of the Case-Control Study?

PubMed Central

Morabia, Alfredo

2013-01-01

In the summer of 1924, an outbreak of scarlet fever occurred in Flint, Michigan. Unable to trace it to the usual causes, particularly fresh milk, the Michigan Department of Health used a novel approach to disentangle the enigma: The 116 cases of scarlet fever were compared with 117 “controls” selected from neighbors of the quarantined cases and from patients at the City Health Center who had been treated for ailments unrelated to scarlet fever. The extraordinary culprit was ice cream, which had a frequent/occasional/none consumption prevalence of 60%, 34%, and 6% among the cases and 24%, 51%, and 25% among the controls, respectively. The 1925 report reads, “Detailed epidemiological investigation, by means of case histories and control histories on well persons, confirmed early suspicions and established the fact that the epidemic was spread by ice cream” (Am J Hyg. 1925;5(5):669–681). This forgotten epidemiologic study is the oldest study using the case-control design to have been resurrected thus far. The case-control study design may have been conceived simultaneously, but independently and for different purposes, in England (Janet Lane-Claypon's 1926 report on the determinants of breast cancer) and the United States. PMID:24064743

The incident user design in comparative effectiveness research.

PubMed

Johnson, Eric S; Bartman, Barbara A; Briesacher, Becky A; Fleming, Neil S; Gerhard, Tobias; Kornegay, Cynthia J; Nourjah, Parivash; Sauer, Brian; Schumock, Glen T; Sedrakyan, Art; Stürmer, Til; West, Suzanne L; Schneeweiss, Sebastian

2013-01-01

Comparative effectiveness research includes cohort studies and registries of interventions. When investigators design such studies, how important is it to follow patients from the day they initiated treatment with the study interventions? Our article considers this question and related issues to start a dialogue on the value of the incident user design in comparative effectiveness research. By incident user design, we mean a study that sets the cohort's inception date according to patients' new use of an intervention. In contrast, most epidemiologic studies enroll patients who were currently or recently using an intervention when follow-up began. We take the incident user design as a reasonable default strategy because it reduces biases that can impact non-randomized studies, especially when investigators use healthcare databases. We review case studies where investigators have explored the consequences of designing a cohort study by restricting to incident users, but most of the discussion has been informed by expert opinion, not by systematic evidence. Published 2012. This article is a U.S. Government work and is in the public domain in the USA.

Integrating malaria surveillance with climate data for outbreak detection and forecasting: the EPIDEMIA system.

PubMed

Merkord, Christopher L; Liu, Yi; Mihretie, Abere; Gebrehiwot, Teklehaymanot; Awoke, Worku; Bayabil, Estifanos; Henebry, Geoffrey M; Kassa, Gebeyaw T; Lake, Mastewal; Wimberly, Michael C

2017-02-23

Early indication of an emerging malaria epidemic can provide an opportunity for proactive interventions. Challenges to the identification of nascent malaria epidemics include obtaining recent epidemiological surveillance data, spatially and temporally harmonizing this information with timely data on environmental precursors, applying models for early detection and early warning, and communicating results to public health officials. Automated web-based informatics systems can provide a solution to these problems, but their implementation in real-world settings has been limited. The Epidemic Prognosis Incorporating Disease and Environmental Monitoring for Integrated Assessment (EPIDEMIA) computer system was designed and implemented to integrate disease surveillance with environmental monitoring in support of operational malaria forecasting in the Amhara region of Ethiopia. A co-design workshop was held with computer scientists, epidemiological modelers, and public health partners to develop an initial list of system requirements. Subsequent updates to the system were based on feedback obtained from system evaluation workshops and assessments conducted by a steering committee of users in the public health sector. The system integrated epidemiological data uploaded weekly by the Amhara Regional Health Bureau with remotely-sensed environmental data freely available from online archives. Environmental data were acquired and processed automatically by the EASTWeb software program. Additional software was developed to implement a public health interface for data upload and download, harmonize the epidemiological and environmental data into a unified database, automatically update time series forecasting models, and generate formatted reports. Reporting features included district-level control charts and maps summarizing epidemiological indicators of emerging malaria outbreaks, environmental risk factors, and forecasts of future malaria risk. Successful implementation and use of EPIDEMIA is an important step forward in the use of epidemiological and environmental informatics systems for malaria surveillance. Developing software to automate the workflow steps while remaining robust to continual changes in the input data streams was a key technical challenge. Continual stakeholder involvement throughout design, implementation, and operation has created a strong enabling environment that will facilitate the ongoing development, application, and testing of the system.

Finnish Prenatal Study of Bipolar Disorders (FIPS-B): overview, design and description of the sample.

PubMed

Chudal, Roshan; Sucksdorff, Dan; Suominen, Auli; Lehti, Venla; Hinkka-Yli-Salomäki, Susanna; Huttunen, Jukka; Ristkari, Terja; Gissler, Mika; McKeague, Ian W; Brown, Alan S; Sourander, Andre

2014-04-01

Bipolar disorders (BPD) are chronic mental illnesses, the development of which involves genetic factors and environmental influences. The aim of this paper is to provide an overall description of the Finnish Prenatal Study of Bipolar Disorders (FIPS-B), including the study design, national registers and linkage of the registers. FIPS-B is a population-based prenatal epidemiological study of BPD with a nested case-control study design using several national registers. The registers used are: the Finnish Medical Birth Register (FMBR), the Finnish Hospital Discharge Register (FHDR), the Population Central Register and the Finnish Maternity Cohort (FMC), which are linked using the unique personal identity code (PIC). FIPS-B includes all children born from January 1, 1983 to December 31, 1998 and diagnosed with BPD in Finland by December 31, 2008. The total number of cases included in the FIPS-B is 1887. The age at first diagnosis ranged from 4 to 25 years. Half (50.4%) of the cases utilized only outpatient services, 12.7% only inpatient services and the rest (36.9%) utilized both services. Offspring of mothers with the lowest educational level had an increased odds of BPD (OR = 1.46, 95% CI 1.13-1.88). The cumulative incidence of BPD in the population aged 25 years or younger was 11.6/10,000 in 2008. FIPS-B has all the strengths of a register-based prenatal epidemiological study, along with the availability of maternal biomarkers, enabling it to examine several prenatal, perinatal and familial risk factors for BPD.

A review of the toxicology and epidemiology of wollastonite.

PubMed

Maxim, L Daniel; McConnell, E E

2005-08-01

Wollastonite is a naturally occurring calcium silicate (CaSiO(3)) that is produced in both powder and fibrous forms. It is a valuable industrial mineral used in plastics, ceramics, metallurgical applications, paint, and friction products. For some applications wollastonite serves as an asbestos replacement. To varying degrees, wollastonite grades contain respirable particles/fibers, some of which have lengths and diameters that might be biologically active if deposited and retained in the lung. In this review we provide background information on wollastonite properties, markets, production and use, regulatory classification, and occupational exposure limits. We also summarize the available studies on the toxicology and epidemiology of wollastonite. We conclude that there is inadequate evidence for the carcinogenicity of wollastonite in animals and, based on strong evidence that wollastonite is not biopersistent, believe that a well-designed animal inhalation bioassay would have a negative result. The epidemiological evidence for wollastonite is limited, but does not suggest that workers are at significant risk of an increased incidence of pulmonary fibrosis, lung cancer, or mesothelioma. Morbidity studies have demonstrated a nonspecific increase in bronchitis and reduced lung function. It is prudent, however, to continue product stewardship efforts by wollastonite producers to control workplace exposures and to monitor scientific developments.

Addressing refugee health through evidence-based policies: a case study

PubMed Central

de Bocanegra, Heike Thiel; Carter-Pokras, Olivia; Ingleby, J. David; Pottie, Kevin; Tchangalova, Nedelina; Allen, Sophia I.; Smith-Gagen, Julie; Hidalgo, Bertha

2017-01-01

The cumulative total of persons forced to leave their country for fear of persecution or organized violence reached an unprecedented 24.5 million by the end of 2015. Providing equitable access to appropriate health services for these highly diverse newcomers poses challenges for receiving countries. In this case study, we illustrate the importance of translating epidemiology into policy to address the health needs of refugees by highlighting examples of what works as well as identifying important policy-relevant gaps in knowledge. First, we formed an international working group of epidemiologists and health services researchers to identify available literature on the intersection of epidemiology, policy, and refugee health. Second, we created a synopsis of findings to inform a recommendation for integration of policy and epidemiology to support refugee health in the US and other high-income receiving countries. Third, we identified eight key areas to guide the involvement of epidemiologists in addressing refugee health concerns. The complexity and uniqueness of refugee health issues, and the need to develop sustainable management information systems, require epidemiologists to expand their repertoire of skills to identify health patterns among arriving refugees, monitor access to appropriately designed health services, address inequities, and communicate with policy makers and multidisciplinary teams. PMID:28554498

Consumption of fruit and vegetables reduces risk of pancreatic cancer: evidence from epidemiological studies.

PubMed

Wu, Qi-Jun; Wu, Lang; Zheng, Li-Qiang; Xu, Xin; Ji, Chao; Gong, Ting-Ting

2016-05-01

Observational studies have reported inconsistent results on the association between fruit and vegetable intake and the risk of pancreatic cancer. We carried out a meta-analysis of epidemiological studies to summarize available evidence. We searched PubMed, Scopus, and ISI Web of Science databases for relevant studies published until the end of January 2015. Fixed-effects and random-effects models were used to estimate the summary relative risks (RRs) and 95% confidence intervals (CIs) for the associations between fruit and vegetable intake and the risk of pancreatic cancer. A total of 15 case-control studies, eight prospective studies, and one pooled analysis fulfilled the inclusion criteria. The summary RR for the highest versus the lowest intake was 0.73 (95% CI=0.53-1.00) for fruit and vegetables, 0.73 (95% CI=0.63-0.84) for fruit, and 0.76 (95% CI=0.69-0.83) for vegetables, with significant heterogeneities (I=70.5, 55.7, and 43.0%, respectively). Inverse associations were observed in the stratified analysis by study design, although the results of prospective studies showed borderline significance, with corresponding RR=0.90 (95% CI=0.77-1.05) for fruit and vegetable intake, 0.93 (95% CI=0.83-1.03) for fruit intake, and 0.89 (95% CI=0.80-1.00) for vegetable intake. Besides, significant inverse associations were observed in the majority of other subgroup analyses by study quality, geographic location, exposure assessment method, and adjustment for potential confounders. Findings from the present meta-analysis support that fruit and vegetable intake is associated inversely with the risk of pancreatic cancer. However, study design may play a key role in the observed magnitude of the aforementioned association. Future well-designed prospective studies are warranted to confirm these findings.

Guidelines for Good Epidemiology Practices for Occupational and Environmental Epidemiologic Research. The Chemical Manufacturers Association's Epidemiology Task Group.

PubMed

1991-12-01

The Guidelines for Good Epidemiology Practices (GEPs) for Occupational and Environmental Epidemiologic Research address the conduct of studies generally undertaken to answer questions about human health in relationship to the work place or the environment. The GEPs propose minimum practices and procedures that should be considered to help ensure the quality and integrity of data used in epidemiologic research and to provide adequate documentation of the research methods. The GEPs address the process of conducting individual epidemiologic studies and do not prescribe specific research methods. The Guidelines for Good Epidemiology Practices propose minimum practices and procedures in the following areas: I. Organization and Personnel II. Facilities, Resource Commitment, and Contractors III. Protocol IV. Review and Approval V. Study Conduct VI. Communication VII. Archiving VIII. Quality Assurance Although the Guidelines for Good Epidemiology Practices will not guarantee good epidemiology, they do provide a useful framework for ensuring that all research issues are adequately addressed. This framework is proposed as a first step in improving epidemiologic research practices through adherence to sound scientific research principles. Appendices provide an overview of standard operating procedures, a glossary of terms used in the Guidelines, and suggested references on occupational epidemiology methods.

Environmental health risks of toxic waste site exposures--an epidemiological perspective.

PubMed

von Schirnding, Y E; Ehrlich, R I

1992-06-06

A general account is given of the problems of assessing the impact of human exposure to toxic waste sites, including the identification of truly exposed populations and of exposure pathways. Epidemiological studies of populations at risk are briefly reviewed and methodological problems summarised. These include the use of relatively weak study designs, inadequate exposure assessment and recall biases associated with symptom reporting among anxious residents living in the vicinity of waste sites. In South Africa, health risks associated with exposure to toxic waste sites need to be viewed in the context of current community health concerns, competing causes of disease and ill-health, and the relative lack of knowledge about environmental contamination and associated health effects. A nonspecific deterioration of health and well-being is more likely to result from waste site exposures than is overt clinical disease. Socially acceptable policies and controls may have to be based on criteria other than demonstrable ill-health. Detailed inventories and registries of the nature of disposed materials need to be maintained, sites of poorly controlled disposal in the past identified and selective environmental monitoring conducted. Epidemiological studies may be justified in situations where exposures well in excess of acceptable norms are demonstrated. An integrated national waste management policy for the country is urgently needed.

Low dose or low dose rate ionizing radiation-induced health effect in the human.

PubMed

Tang, Feng Ru; Loganovsky, Konstantin

2018-06-05

The extensive literature review on human epidemiological studies suggests that low dose ionizing radiation (LDIR) (≤100 mSv) or low dose rate ionizing radiation (LDRIR) (<6mSv/H) exposure could induce either negative or positive health effects. These changes may depend on genetic background, age (prenatal day for embryo), sex, nature of radiation exposure, i.e., acute or chronic irradiation, radiation sources (such as atomic bomb attack, fallout from nuclear weapon test, nuclear power plant accidents, 60 Co-contaminated building, space radiation, high background radiation, medical examinations or procedures) and radionuclide components and human epidemiological experimental designs. Epidemiological and clinical studies show that LDIR or LDRIR exposure may induce cancer, congenital abnormalities, cardiovascular and cerebrovascular diseases, cognitive and other neuropsychiatric disorders, cataracts and other eye and somatic pathology (endocrine, bronchopulmonary, digestive, etc). LDIR or LDRIR exposure may also reduce mutation and cancer mortality rates. So far, the mechanisms of LDIR- or LDRIR -induced health effect are poorly understood. Further extensive studies are still needed to clarify under what circumstances, LDIR or LDRIR exposure may induce positive or negative effects, which may facilitate development of new therapeutic approaches to prevent or treat the radiation-induced human diseases or enhance radiation-induced positive health effect. Copyright © 2018 Elsevier Ltd. All rights reserved.

Strengthening the Reporting of Observational Studies in Epidemiology—Nutritional Epidemiology (STROBE-nut): An Extension of the STROBE Statement

PubMed Central

Hawwash, Dana; Ocké, Marga C.; Berg, Christina; Forsum, Elisabet; Sonestedt, Emily; Wirfält, Elisabet; Åkesson, Agneta; Kolsteren, Patrick; Byrnes, Graham; De Keyzer, Willem; Van Camp, John; Slimani, Nadia; Cevallos, Myriam; Egger, Matthias; Huybrechts, Inge

2016-01-01

Background Concerns have been raised about the quality of reporting in nutritional epidemiology. Research reporting guidelines such as the Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) statement can improve quality of reporting in observational studies. Herein, we propose recommendations for reporting nutritional epidemiology and dietary assessment research by extending the STROBE statement into Strengthening the Reporting of Observational Studies in Epidemiology—Nutritional Epidemiology (STROBE-nut). Methods and Findings Recommendations for the reporting of nutritional epidemiology and dietary assessment research were developed following a systematic and consultative process, coordinated by a multidisciplinary group of 21 experts. Consensus on reporting guidelines was reached through a three-round Delphi consultation process with 53 external experts. In total, 24 recommendations for nutritional epidemiology were added to the STROBE checklist. Conclusion When used appropriately, reporting guidelines for nutritional epidemiology can contribute to improve reporting of observational studies with a focus on diet and health. PMID:27270749

The Effect of Self-Reported and Performance-Based Functional Impairment on Future Hospital Costs of Community-Dwelling Older Persons

ERIC Educational Resources Information Center

Reuben, David B.; Seeman, Teresa E.; Keeler, Emmett; Hayes, Risa P.; Bowman, Lee; Sewall, Ase; Hirsch, Susan H.; Wallace, Robert B.; Guralnik, Jack M.

2004-01-01

Purpose: We determined the prognostic value of self-reported and performance-based measurement of function, including functional transitions and combining different measurement approaches, on utilization. Design and Methods: Our cohort study used the 6th, 7th, and 10th waves of three sites of the Established Populations for Epidemiologic Studies…

Personal use of hair dyes and the risk of bladder cancer: results of a meta-analysis.

PubMed Central

Huncharek, Michael; Kupelnick, Bruce

2005-01-01

OBJECTIVE: This study examined the methodology of observational studies that explored an association between personal use of hair dye products and the risk of bladder cancer. METHODS: Data were pooled from epidemiological studies using a general variance-based meta-analytic method that employed confidence intervals. The outcome of interest was a summary relative risk (RRs) reflecting the risk of bladder cancer development associated with use of hair dye products vs. non-use. Sensitivity analyses were performed to explain any observed statistical heterogeneity and to explore the influence of specific study characteristics of the summary estimate of effect. RESULTS: Initially combining homogenous data from six case-control and one cohort study yielded a non-significant RR of 1.01 (0.92, 1.11), suggesting no association between hair dye use and bladder cancer development. Sensitivity analyses examining the influence of hair dye type, color, and study design on this suspected association showed that uncontrolled confounding and design limitations contributed to a spurious non-significant summary RR. The sensitivity analyses yielded statistically significant RRs ranging from 1.22 (1.11, 1.51) to 1.50 (1.30, 1.98), indicating that personal use of hair dye products increases bladder cancer risk by 22% to 50% vs. non-use. CONCLUSION: The available epidemiological data suggest an association between personal use of hair dye products and increased risk of bladder cancer. PMID:15736329

Flavonoids, Flavonoid Subclasses, and Esophageal Cancer Risk: A Meta-Analysis of Epidemiologic Studies

PubMed Central

Cui, Lingling; Liu, Xinxin; Tian, Yalan; Xie, Chen; Li, Qianwen; Cui, Han; Sun, Changqing

2016-01-01

Flavonoids have been suggested to play a chemopreventive role in carcinogenesis. However, the epidemiologic studies assessing dietary intake of flavonoids and esophageal cancer risk have yielded inconsistent results. This study was designed to examine the association between flavonoids, each flavonoid subclass, and the risk of esophageal cancer with a meta-analysis approach. We searched for all relevant studies with a prospective cohort or case-control study design published from January 1990 to April 2016, using PUBMED, EMBASE, and Web of Science. Pooled odds ratios (ORs) were calculated using fixed or random-effect models. In total, seven articles including 2629 cases and 481,193 non-cases were selected for the meta-analysis. Comparing the highest-intake patients with the lowest-intake patients for total flavonoids and for each flavonoid subclass, we found that anthocyanidins (OR = 0.60, 95% CI: 0.49–0.74), flavanones (OR = 0.65, 95% CI: 0.49–0.86), and flavones (OR = 0.78, 95% CI 0.64–0.95) were inversely associated with the risk of esophageal cancer. However, total flavonoids showed marginal association with esophageal cancer risk (OR = 0.78, 95% CI: 0.59–1.04). In conclusion, our study suggested that dietary intake of total flavonoids, anthocyanidins, flavanones, and flavones might reduce the risk of esophageal cancer. PMID:27338463

Epidemiological Differences Between Localised and Non-Localised Low Back Pain

PubMed Central

Coggon, David; Ntani, Georgia; Walker-Bone, Karen; Palmer, Keith T; Felli, Vanda E; Harari, Raul; Barrero, Lope H; Felknor, Sarah A.; Gimeno, David; Cattrell, Anna; Vargas-Prada, Sergio; Bonzini, Matteo; Solidaki, Eleni; Merisalu, Eda; Habib, Rima R.; Sadeghian, Farideh; Kadir, M Masood; Warnakulasuriya, Sudath SP; Matsudaira, Ko; Nyantumbu, Busisiwe; Sim, Malcolm R; Harcombe, Helen; Cox, Ken; Sarquis, Leila M M; Marziale, Maria H; Harari, Florencia; Freire, Rocio; Harari, Natalia; Monroy, Magda V; Quintana, Leonardo A; Rojas, Marianela; Harris, E Clare; Serra, Consol; Martinez, J Miguel; Delclos, George; Benavides, Fernando G; Carugno, Michele; Ferrario, Marco M; Pesatori, Angela C; Chatzi, Leda; Bitsios, Panos; Kogevinas, Manolis; Oha, Kristel; Freimann, Tiina; Sadeghian, Ali; Peiris-John, Roshini J; Sathiakumar, Nalini; Wickremasinghe, A Rajitha; Yoshimura, Noriko; Kelsall, Helen L; Hoe, Victor C W; Urquhart, Donna M; Derrett, Sarah; McBride, David; Herbison, Peter; Gray, Andrew; Salazar Vega, Eduardo J.

2017-01-01

Study design Cross-sectional survey with longitudinal follow-up Objectives To test the hypothesis that pain which is localised to the low back differs epidemiologically from that which occurs simultaneously or close in time to pain at other anatomical sites Summary of background data Low back pain (LBP) often occurs in combination with other regional pain, with which it shares similar psychological and psychosocial risk factors. However, few previous epidemiological studies of LBP have distinguished pain that is confined to the low back from that which occurs as part of a wider distribution of pain. Methods We analysed data from a cohort study of musculoskeletal pain and associated disability in 47 occupational groups from 18 countries. Results Among 12,197 subjects at baseline, 609 (4.9%) reported localised LBP in the past month, and 3,820 (31.3%) non-localised LBP. Non-localised LBP was more frequently associated with sciatica in the past month (48.1% vs. 30.0% of cases), occurred on more days in the past month and past year, was more often disabling for everyday activities (64.1% vs. 47.3% of cases), and had more frequently led to medical consultation and sickness absence from work. It was also more often persistent when participants were followed up after a mean of 14 months (65.6% vs. 54.1% of cases). In adjusted Poisson regression analyses, non-localised LBP was differentially associated with female sex, older age, somatising tendency, poor mental health and report of time pressure at work,. There were also marked differences in the relative prevalence of localised and non-localised LBP by occupational group. Conclusions Future epidemiological studies should distinguish where possible between pain that is limited to the low back and LBP which occurs in association with pain at other anatomical locations. PMID:27820794

Inferring population-level contact heterogeneity from common epidemic data

PubMed Central

Stack, J. Conrad; Bansal, Shweta; Kumar, V. S. Anil; Grenfell, Bryan

2013-01-01

Models of infectious disease spread that incorporate contact heterogeneity through contact networks are an important tool for epidemiologists studying disease dynamics and assessing intervention strategies. One of the challenges of contact network epidemiology has been the difficulty of collecting individual and population-level data needed to develop an accurate representation of the underlying host population's contact structure. In this study, we evaluate the utility of common epidemiological measures (R0, epidemic peak size, duration and final size) for inferring the degree of heterogeneity in a population's unobserved contact structure through a Bayesian approach. We test the method using ground truth data and find that some of these epidemiological metrics are effective at classifying contact heterogeneity. The classification is also consistent across pathogen transmission probabilities, and so can be applied even when this characteristic is unknown. In particular, the reproductive number, R0, turns out to be a poor classifier of the degree heterogeneity, while, unexpectedly, final epidemic size is a powerful predictor of network structure across the range of heterogeneity. We also evaluate our framework on empirical epidemiological data from past and recent outbreaks to demonstrate its application in practice and to gather insights about the relevance of particular contact structures for both specific systems and general classes of infectious disease. We thus introduce a simple approach that can shed light on the unobserved connectivity of a host population given epidemic data. Our study has the potential to inform future data-collection efforts and study design by driving our understanding of germane epidemic measures, and highlights a general inferential approach to learning about host contact structure in contemporary or historic populations of humans and animals. PMID:23034353

The methodology of population surveys of headache prevalence, burden and cost: Principles and recommendations from the Global Campaign against Headache

PubMed Central

2014-01-01

The global burden of headache is very large, but knowledge of it is far from complete and needs still to be gathered. Published population-based studies have used variable methodology, which has influenced findings and made comparisons difficult. Among the initiatives of the Global Campaign against Headache to improve and standardize methods in use for cross-sectional studies, the most important is the production of consensus-based methodological guidelines. This report describes the development of detailed principles and recommendations. For this purpose we brought together an expert consensus group to include experience and competence in headache epidemiology and/or epidemiology in general and drawn from all six WHO world regions. The recommendations presented are for anyone, of whatever background, with interests in designing, performing, understanding or assessing studies that measure or describe the burden of headache in populations. While aimed principally at researchers whose main interests are in the field of headache, they should also be useful, at least in parts, to those who are expert in public health or epidemiology and wish to extend their interest into the field of headache disorders. Most of all, these recommendations seek to encourage collaborations between specialists in headache disorders and epidemiologists. The focus is on migraine, tension-type headache and medication-overuse headache, but they are not intended to be exclusive to these. The burdens arising from secondary headaches are, in the majority of cases, more correctly attributed to the underlying disorders. Nevertheless, the principles outlined here are relevant for epidemiological studies on secondary headaches, provided that adequate definitions can be not only given but also applied in questionnaires or other survey instruments. PMID:24467862

Application description and policy model in collaborative environment for sharing of information on epidemiological and clinical research data sets.

PubMed

de Carvalho, Elias César Araujo; Batilana, Adelia Portero; Simkins, Julie; Martins, Henrique; Shah, Jatin; Rajgor, Dimple; Shah, Anand; Rockart, Scott; Pietrobon, Ricardo

2010-02-19

Sharing of epidemiological and clinical data sets among researchers is poor at best, in detriment of science and community at large. The purpose of this paper is therefore to (1) describe a novel Web application designed to share information on study data sets focusing on epidemiological clinical research in a collaborative environment and (2) create a policy model placing this collaborative environment into the current scientific social context. The Database of Databases application was developed based on feedback from epidemiologists and clinical researchers requiring a Web-based platform that would allow for sharing of information about epidemiological and clinical study data sets in a collaborative environment. This platform should ensure that researchers can modify the information. A Model-based predictions of number of publications and funding resulting from combinations of different policy implementation strategies (for metadata and data sharing) were generated using System Dynamics modeling. The application allows researchers to easily upload information about clinical study data sets, which is searchable and modifiable by other users in a wiki environment. All modifications are filtered by the database principal investigator in order to maintain quality control. The application has been extensively tested and currently contains 130 clinical study data sets from the United States, Australia, China and Singapore. Model results indicated that any policy implementation would be better than the current strategy, that metadata sharing is better than data-sharing, and that combined policies achieve the best results in terms of publications. Based on our empirical observations and resulting model, the social network environment surrounding the application can assist epidemiologists and clinical researchers contribute and search for metadata in a collaborative environment, thus potentially facilitating collaboration efforts among research communities distributed around the globe.

Effects of bisphenol A on male and couple reproductive health: a review.

PubMed

Mínguez-Alarcón, Lidia; Hauser, Russ; Gaskins, Audrey J

2016-09-15

Bisphenol A (BPA) is a ubiquitous environmental toxicant with endocrine-disrupting properties and is suspected to affect human reproduction. The objective of this review was to summarize the potential effects of male exposure to BPA on markers of testicular function and couple reproductive outcomes. Five epidemiologic studies on BPA and reproductive hormones all found significant associations with at least one reproductive hormone; however, no consistent relationships were observed across studies. Six epidemiologic studies evaluated the relation between BPA and semen parameters, and although the majority reported negative associations with various parameters, there were few consistent trends across studies. Finally, three epidemiologic studies examined BPA and couple reproductive outcomes, and only one found an association. Overall, the evidence supporting an association between BPA exposure and adverse male reproductive health outcomes in humans remains limited and inconclusive. Reasons for the discrepancies in results could include, but are not limited to, differences in study populations (e.g., fertile vs. subfertile men), BPA urinary concentrations (occupationally vs. nonoccupationally exposed), misclassification of BPA exposure (e.g., using one urine sample to characterize exposure vs. multiple samples), sample sizes, study design (e.g., cross-sectional vs. prospective), and residual confounding (e.g., due to diet and lifestyle factors). It is also possible that some of the statistically significant findings were due to chance alone. Clearly, further studies are needed to further clarify the role of this ubiquitous endocrine-disrupting chemical on male reproductive health. Copyright © 2016. Published by Elsevier Inc.

Predicting outcome of status epilepticus.

PubMed

Leitinger, M; Kalss, G; Rohracher, A; Pilz, G; Novak, H; Höfler, J; Deak, I; Kuchukhidze, G; Dobesberger, J; Wakonig, A; Trinka, E

2015-08-01

Status epilepticus (SE) is a frequent neurological emergency complicated by high mortality and often poor functional outcome in survivors. The aim of this study was to review available clinical scores to predict outcome. Literature review. PubMed Search terms were "score", "outcome", and "status epilepticus" (April 9th 2015). Publications with abstracts available in English, no other language restrictions, or any restrictions concerning investigated patients were included. Two scores were identified: "Status Epilepticus Severity Score--STESS" and "Epidemiology based Mortality score in SE--EMSE". A comprehensive comparison of test parameters concerning performance, options, and limitations was performed. Epidemiology based Mortality score in SE allows detailed individualization of risk factors and is significantly superior to STESS in a retrospective explorative study. In particular, EMSE is very good at detection of good and bad outcome, whereas STESS detecting bad outcome is limited by a ceiling effect and uncertainty of correct cutoff value. Epidemiology based Mortality score in SE can be adapted to different regions in the world and to advances in medicine, as new data emerge. In addition, we designed a reporting standard for status epilepticus to enhance acquisition and communication of outcome relevant data. A data acquisition sheet used from patient admission in emergency room, from the EEG lab to intensive care unit, is provided for optimized data collection. Status Epilepticus Severity Score is easy to perform and predicts bad outcome, but has a low predictive value for good outcomes. Epidemiology based Mortality score in SE is superior to STESS in predicting good or bad outcome but needs marginally more time to perform. Epidemiology based Mortality score in SE may prove very useful for risk stratification in interventional studies and is recommended for individual outcome prediction. Prospective validation in different cohorts is needed for EMSE, whereas STESS needs further validation in cohorts with a wider range of etiologies. This article is part of a Special Issue entitled "Status Epilepticus". Copyright © 2015. Published by Elsevier Inc.

[How to write high-quality epidemiological research paper Ⅵ. Strengthening the Reporting of Observational Studies in Epidemiology-Nutritional Epidemiology (STROBE-nut)].

PubMed

Ding, C Y; Cao, Y; Yang, C; Sun, F; Zhan, S Y

2017-01-10

Concerns have been raised about the reporting quality in nutritional epidemiology. Therefore, strengthening the reporting of observational studies in epidemiology-nutritional epidemiology (STROBE-nut) has been proposed by extending the STROBE statement to include additional recommendations on issues related to nutritional epidemiology and dietary assessment, aiming to provide more specific guidelines on how to report observational research in the field. This paper presents a brief introduction to STROBE-nut and also an explanation of the key points in the additional items, with an example illustrating the application of the checklist.

Indoor radon and childhood leukaemia.

PubMed

Raaschou-Nielsen, Ole

2008-01-01

This paper summarises the epidemiological literature on domestic exposure to radon and risk for childhood leukaemia. The results of 12 ecological studies show a consistent pattern of higher incidence and mortality rates for childhood leukaemia in areas with higher average indoor radon concentrations. Although the results of such studies are useful to generate hypotheses, they must be interpreted with caution, as the data were aggregated and analysed for geographical areas and not for individuals. The seven available case-control studies of childhood leukaemia with measurement of radon concentrations in the residences of cases and controls gave mixed results, however, with some indication of a weak (relative risk < 2) association with acute lymphoblastic leukaemia. The epidemiological evidence to date suggests that an association between indoor exposure to radon and childhood leukaemia might exist, but is weak. More case-control studies are needed, with sufficient statistical power to detect weak associations and based on designs and methods that minimise misclassification of exposure and provide a high participation rate and low potential selection bias.

Smoking, caning, and delinquency in a secondary modern school.

PubMed

Palmer, J W

2015-02-01

This study was designed in 1962 to investigate the reformative effect of a particular punishment (caning) for a particular offence (smoking by schoolboys). In 1964, in the course of a larger study of juvenile offences, delinquency records were obtained from the police, and the relationship between smoking and delinquency is also discussed in this paper. © The Author 2015; all rights reserved. Published by Oxford University Press on behalf of the International Epidemiological Association.

Cordless telephone use: implications for mobile phone research.

PubMed

Redmayne, Mary; Inyang, Imo; Dimitriadis, Christina; Benke, Geza; Abramson, Michael J

2010-04-01

Cordless and mobile (cellular) telephone use has increased substantially in recent years causing concerns about possible health effects. This has led to much epidemiological research, but the usual focus is on mobile telephone radiofrequency (RF) exposure only despite cordless RF being very similar. Access to and use of cordless phones were included in the Mobile Radiofrequency Phone Exposed Users Study (MoRPhEUS) of 317 Year 7 students recruited from Melbourne, Australia. Participants completed an exposure questionnaire-87% had a cordless phone at home and 77% owned a mobile phone. There was a statistically significant positive relationship (r = 0.38, p < 0.01) between cordless and mobile phone use. Taken together, this increases total RF exposure and its ratio in high-to-low mobile users. Therefore, the design and analysis of future epidemiological telecommunication studies need to assess cordless phone exposure to accurately evaluate total RF telephone exposure effects.

Impact of committed individuals on vaccination behavior

NASA Astrophysics Data System (ADS)

Liu, Xiao-Tao; Wu, Zhi-Xi; Zhang, Lianzhong

2012-11-01

We study how the presence of committed vaccinators, a small fraction of individuals who consistently hold the vaccinating strategy and are immune to influence, impact the vaccination dynamics in well-mixed and spatially structured populations. For this purpose, we develop an epidemiological game-theoretic model of a flu-like vaccination by integrating an epidemiological process into a simple agent-based model of adaptive learning, where individuals (except for those committed ones) use anecdotal evidence to estimate costs and benefits of vaccination. We show that the committed vaccinators, acting as “steadfast role models” in the populations, can efficiently avoid the clustering of susceptible individuals and stimulate other imitators to take vaccination, hence contributing to the promotion of vaccine uptake. We substantiate our findings by making comparative studies of our model on a full lattice and on a randomly diluted one. Our work is expected to provide valuable information for decision-making and design more effective disease-control strategy.

The influence of the work environment on cardiovascular health: a historical, conceptual, and methodological perspective.

PubMed

Kasl, S V

1996-01-01

The framework of psychosocial epidemiology is used to examine research developments that characterize the accumulation of knowledge regarding the role of the work environment in cardiovascular health and disease. The discussion of current programs of research focuses on the work of T. Theorell and R. Karasek (1996) and J. Siegrist (1996) as exemplars of European and American studies that have contributed the most to the understanding of occupational cardiovascular health. It is argued that researchers need to maintain and nurture relatively broad conceptual models of etiology because cardiovascular disease involves multiple biomedical risk factors and because specific aspects of the work environment are embedded in a large, complex matrix of other psychosocial influences. At the same time, investigators need to push ahead with focused research strategies to clarify the precise nature of the work environmental risk factors that emerge in the broad, somewhat imprecise epidemiologic study designs.

Primer Part 1-The building blocks of epilepsy genetics.

PubMed

Helbig, Ingo; Heinzen, Erin L; Mefford, Heather C

2016-06-01

This is the first of a two-part primer on the genetics of the epilepsies within the Genetic Literacy Series of the Genetics Commission of the International League Against Epilepsy. In Part 1, we cover the foundations of epilepsy genetics including genetic epidemiology and the range of genetic variants that can affect the risk for developing epilepsy. We discuss various epidemiologic study designs that have been applied to the genetics of the epilepsies including population studies, which provide compelling evidence for a strong genetic contribution in many epilepsies. We discuss genetic risk factors varying in size, frequency, inheritance pattern, effect size, and phenotypic specificity, and provide examples of how genetic risk factors within the various categories increase the risk for epilepsy. We end by highlighting trends in epilepsy genetics including the increasing use of massive parallel sequencing technologies. Wiley Periodicals, Inc. © 2016 International League Against Epilepsy.

An approach to checking case-crossover analyses based on equivalence with time-series methods.

PubMed

Lu, Yun; Symons, James Morel; Geyh, Alison S; Zeger, Scott L

2008-03-01

The case-crossover design has been increasingly applied to epidemiologic investigations of acute adverse health effects associated with ambient air pollution. The correspondence of the design to that of matched case-control studies makes it inferentially appealing for epidemiologic studies. Case-crossover analyses generally use conditional logistic regression modeling. This technique is equivalent to time-series log-linear regression models when there is a common exposure across individuals, as in air pollution studies. Previous methods for obtaining unbiased estimates for case-crossover analyses have assumed that time-varying risk factors are constant within reference windows. In this paper, we rely on the connection between case-crossover and time-series methods to illustrate model-checking procedures from log-linear model diagnostics for time-stratified case-crossover analyses. Additionally, we compare the relative performance of the time-stratified case-crossover approach to time-series methods under 3 simulated scenarios representing different temporal patterns of daily mortality associated with air pollution in Chicago, Illinois, during 1995 and 1996. Whenever a model-be it time-series or case-crossover-fails to account appropriately for fluctuations in time that confound the exposure, the effect estimate will be biased. It is therefore important to perform model-checking in time-stratified case-crossover analyses rather than assume the estimator is unbiased.

Ambient Temperature and Morbidity: A Review of Epidemiological Evidence

PubMed Central

Ye, Xiaofang; Wolff, Rodney; Yu, Weiwei; Vaneckova, Pavla; Pan, Xiaochuan

2011-01-01

Objective: In this paper, we review the epidemiological evidence on the relationship between ambient temperature and morbidity. We assessed the methodological issues in previous studies and proposed future research directions. Data sources and data extraction: We searched the PubMed database for epidemiological studies on ambient temperature and morbidity of noncommunicable diseases published in refereed English journals before 30 June 2010. Forty relevant studies were identified. Of these, 24 examined the relationship between ambient temperature and morbidity, 15 investigated the short-term effects of heat wave on morbidity, and 1 assessed both temperature and heat wave effects. Data synthesis: Descriptive and time-series studies were the two main research designs used to investigate the temperature–morbidity relationship. Measurements of temperature exposure and health outcomes used in these studies differed widely. The majority of studies reported a significant relationship between ambient temperature and total or cause-specific morbidities. However, there were some inconsistencies in the direction and magnitude of nonlinear lag effects. The lag effect of hot temperature on morbidity was shorter (several days) compared with that of cold temperature (up to a few weeks). The temperature–morbidity relationship may be confounded or modified by sociodemographic factors and air pollution. Conclusions: There is a significant short-term effect of ambient temperature on total and cause-specific morbidities. However, further research is needed to determine an appropriate temperature measure, consider a diverse range of morbidities, and to use consistent methodology to make different studies more comparable. PMID:21824855

Global Epidemiology of Amyotrophic Lateral Sclerosis: a Systematic Review of the Published Literature

PubMed Central

Chiò, A; Logroscino, G; Traynor, BJ; Collins, J; Simeone, JC; Goldstein, LA; White, LA

2014-01-01

Background Amyotrophic lateral sclerosis (ALS) is relatively rare, yet the economic and social burden is substantial. Having accurate incidence and prevalence estimates would facilitate efficient allocation of healthcare resources. Objective To provide a comprehensive and critical review of the epidemiologic literature on ALS. Methods MEDLINE and EMBASE (1995–2011) databases of population-based studies on ALS incidence and prevalence reporting quantitative data were analyzed. Data extracted included study location and time, design and data sources, case ascertainment methods, and incidence and/or prevalence rates. Medians and inter-quartile ranges (IQRs) were calculated, and ALS case estimates derived using 2010 population estimates. Results In all, 37 articles met inclusion criteria. In Europe, the median (IQR) incidence rate (/100,000 population) was 2.08 (1.47–2.43), corresponding to an estimated 15,355 (10,852–17,938) cases. Median (IQR) prevalence (/100,000 population) was 5.40 (4.06–7.89), or 39,863 (29,971–58,244) prevalent cases. Conclusions Disparity in rates among ALS incidence and prevalence studies may be due to differences in study design or true variations in population demographics, such as age, and geography, including environmental factors and genetic predisposition. Additional large-scale studies that use standardized case ascertainment methods are needed to more accurately assess the true global burden of ALS. PMID:23860588

WISARD: workbench for integrated superfast association studies for related datasets.

PubMed

Lee, Sungyoung; Choi, Sungkyoung; Qiao, Dandi; Cho, Michael; Silverman, Edwin K; Park, Taesung; Won, Sungho

2018-04-20

A Mendelian transmission produces phenotypic and genetic relatedness between family members, giving family-based analytical methods an important role in genetic epidemiological studies-from heritability estimations to genetic association analyses. With the advance in genotyping technologies, whole-genome sequence data can be utilized for genetic epidemiological studies, and family-based samples may become more useful for detecting de novo mutations. However, genetic analyses employing family-based samples usually suffer from the complexity of the computational/statistical algorithms, and certain types of family designs, such as incorporating data from extended families, have rarely been used. We present a Workbench for Integrated Superfast Association studies for Related Data (WISARD) programmed in C/C++. WISARD enables the fast and a comprehensive analysis of SNP-chip and next-generation sequencing data on extended families, with applications from designing genetic studies to summarizing analysis results. In addition, WISARD can automatically be run in a fully multithreaded manner, and the integration of R software for visualization makes it more accessible to non-experts. Comparison with existing toolsets showed that WISARD is computationally suitable for integrated analysis of related subjects, and demonstrated that WISARD outperforms existing toolsets. WISARD has also been successfully utilized to analyze the large-scale massive sequencing dataset of chronic obstructive pulmonary disease data (COPD), and we identified multiple genes associated with COPD, which demonstrates its practical value.

Spontaneous pregnancy loss in humans and exposure to arsenic in drinking water.

PubMed

Bloom, Michael S; Fitzgerald, Edward F; Kim, Keewan; Neamtiu, Iulia; Gurzau, Eugen S

2010-11-01

Maternal exposure to high concentrations of inorganic arsenic (iAs) in naturally contaminated drinking groundwater sources has been associated with an increased risk for the spontaneous loss of clinically recognized pregnancies in several epidemiologic studies. Whereas a large worldwide population depends on drinking groundwater sources with high levels of iAs contamination, in quantities exceeding 10 parts per billion (ppb), an even larger population is likely to be exposed to mild-moderate drinking groundwater iAs contamination, in quantities <10ppb. Only a single epidemiologic study to date has considered spontaneous pregnancy loss in association with consumption of drinking water with mild-moderate iAs contamination; the vast majority of published studies of spontaneous loss addressed populations with substantial exposure. The aim of this review is to evaluate the published literature to assess the plausibility for a causal association between exposure to iAs-contaminated drinking water and the spontaneous loss of clinically recognized pregnancy. In spite of numerous methodologic limitations resulting from circumstance or design, a consistent pattern of increased risk for loss is suggested by the epidemiologic literature. Moreover, these study results are corroborated by a large number of experimental studies, albeit usually conducted at concentrations exceeding that to which humans are exposed via contaminated drinking water. In this review, we discuss sources of human iAs exposure, highlight several experimental studies pertinent to a possible causal link between iAs and spontaneous pregnancy loss in humans, and provide a critical review of published epidemiologic studies of pregnancy loss and drinking water iAs exposures, and their limitations. Based on a review of the published literature, we recommend the future conduct of a two-stage comprehensive prospective study of low-moderate iAs drinking water exposure and spontaneous pregnancy loss. Copyright © 2010 Elsevier GmbH. All rights reserved.

Realist explanatory theory building method for social epidemiology: a protocol for a mixed method multilevel study of neighbourhood context and postnatal depression.

PubMed

Eastwood, John G; Jalaludin, Bin B; Kemp, Lynn A

2014-01-01

A recent criticism of social epidemiological studies, and multi-level studies in particular has been a paucity of theory. We will present here the protocol for a study that aims to build a theory of the social epidemiology of maternal depression. We use a critical realist approach which is trans-disciplinary, encompassing both quantitative and qualitative traditions, and that assumes both ontological and hierarchical stratification of reality. We describe a critical realist Explanatory Theory Building Method comprising of an: 1) emergent phase, 2) construction phase, and 3) confirmatory phase. A concurrent triangulated mixed method multilevel cross-sectional study design is described. The Emergent Phase uses: interviews, focus groups, exploratory data analysis, exploratory factor analysis, regression, and multilevel Bayesian spatial data analysis to detect and describe phenomena. Abductive and retroductive reasoning will be applied to: categorical principal component analysis, exploratory factor analysis, regression, coding of concepts and categories, constant comparative analysis, drawing of conceptual networks, and situational analysis to generate theoretical concepts. The Theory Construction Phase will include: 1) defining stratified levels; 2) analytic resolution; 3) abductive reasoning; 4) comparative analysis (triangulation); 5) retroduction; 6) postulate and proposition development; 7) comparison and assessment of theories; and 8) conceptual frameworks and model development. The strength of the critical realist methodology described is the extent to which this paradigm is able to support the epistemological, ontological, axiological, methodological and rhetorical positions of both quantitative and qualitative research in the field of social epidemiology. The extensive multilevel Bayesian studies, intensive qualitative studies, latent variable theory, abductive triangulation, and Inference to Best Explanation provide a strong foundation for Theory Construction. The study will contribute to defining the role that realism and mixed methods can play in explaining the social determinants and developmental origins of health and disease.

Bisphenol A and human health: a review of the literature.

PubMed

Rochester, Johanna R

2013-12-01

There is growing evidence that bisphenol A (BPA) may adversely affect humans. BPA is an endocrine disruptor that has been shown to be harmful in laboratory animal studies. Until recently, there were relatively few epidemiological studies examining the relationship between BPA and health effects in humans. However, in the last year, the number of these studies has more than doubled. A comprehensive literature search found 91 studies linking BPA to human health; 53 published within the last year. This review outlines this body of literature, showing associations between BPA exposure and adverse perinatal, childhood, and adult health outcomes, including reproductive and developmental effects, metabolic disease, and other health effects. These studies encompass both prenatal and postnatal exposures, and include several study designs and population types. While it is difficult to make causal links with epidemiological studies, the growing human literature correlating environmental BPA exposure to adverse effects in humans, along with laboratory studies in many species including primates, provides increasing support that environmental BPA exposure can be harmful to humans, especially in regards to behavioral and other effects in children. Copyright © 2013 Elsevier Inc. All rights reserved.

Feasibility of epidemiological monitoring for a proposed coal-fired power plant, Ivanpah, California.

PubMed

Goldsmith, J R; Spivey, G H; Coulson, A H

1984-01-27

The authors were asked to determine the feasibility of conducting epidemiologic monitoring for adverse health impact of emissions from the proposed Ivanpah Coal-Fired Power Plant. The study was required by the licensing agency, and specifically concerned health effects on the surrounding community. No potential occupational effects were considered. The area of concern was limited by the licensing agency to a circle of 50 mile radius around the Ivanpah site. The proposed power plant will be capable of generating 1500 megawatts of electricity utilizing low sulfur western coal. It is designed with stack heights of 500 feet for good dispersion and is planned to be outfitted with the best available stack emission control equipment. To establish whether an epidemiologic study is feasible, one must determine: (1) the size of the population which potentially would be exposed; (2) the pollutants to which that population might be exposed and the expected level of exposure and (3) the known or expected health effects of these pollutants and the frequency of such health outcomes. In addition, as in any epidemiologic study, the choice of a proper comparison group, the acceptability of a study to the population to be monitored and costs of the study in relation to available resources must also be taken into account. The population residing within 20 miles of the site consists of approximately 1,500 people at the present time. This population is not expected to increase significantly, although there is the possibility of growth of a "company town" surrounding the plant. Such an event would clearly alter the feasibility of conducting an epidemiologic study. Air quality modeling was used to predict the exposures to the population from various emissions from the proposed generating station. It was based on worst-case assumptions of wind speed, direction, atmospheric stability and percent sulfur-content coal. While a great many pollutants may result from coal burning, the levels of all pollutants, with the possible exception of ozone, are expected to be much lower than existing standards allow and therefore of little practical concern in the communities near Ivanpah. Since ozone is not a primary pollutant but is of secondary origin, its concentration, given the appropriate conditions, could increase with distance from the plant. None of the expected health outcomes occurs with sufficient frequency to allow the detection, with a reasonable degree of statistical certainty, of any reasonably expected increase in frequency in an epidemiologic study of a population as small as that which is associated with the Ivanpah site.(ABSTRACT TRUNCATED AT 400 WORDS)

Epidemiology of multiple childhood traumatic events: child abuse, parental psychopathology, and other family-level stressors.

PubMed

Menard, C B; Bandeen-Roche, K J; Chilcoat, H D

2004-11-01

Multiple family-level childhood stressors are common and are correlated. It is unknown if clusters of commonly co-occurring stressors are identifiable. The study was designed to explore family-level stressor clustering in the general population, to estimate the prevalence of exposure classes, and to examine the correlation of sociodemographic characteristics with class prevalence. Data were collected from an epidemiological sample and analyzed using latent class regression. A six-class solution was identified. Classes were characterized by low risk (prevalence=23%), universal high risk (7 %), family conflict (11 %), household substance problems (22 %), non-nuclear family structure (24 %), parent's mental illness (13 %). Class prevalence varied with race and welfare status, not gender. Interventions for childhood stressors are person-focused; the analytic approach may uniquely inform resource allocation.

Hill's Heuristics and Explanatory Coherentism in Epidemiology.

PubMed

Dammann, Olaf

2018-01-01

In this essay, I argue that Ted Poston's theory of explanatory coherentism is well-suited as a tool for causal explanation in the health sciences, particularly in epidemiology. Coherence has not only played a role in epidemiology for more than half a century as one of Hill's viewpoints, it can also provide background theory for the development of explanatory systems by integrating epidemiologic evidence with a diversity of other error-independent data. I propose that computational formalization of Hill's viewpoints in an explanatory coherentist framework would provide an excellent starting point for a formal epistemological (knowledge-theoretical) project designed to improve causal explanation in the health sciences. As an example, I briefly introduce Paul Thagard's ECHO system and offer my responses to possible objections to my proposal. © The Author(s) 2017. Published by Oxford University Press on behalf of the Johns Hopkins Bloomberg School of Public Health. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

The epidemiology and re-employment outcomes of 467 workers with industrial injuries.

PubMed

Li, Kuicheng; Tang, Dan; Xu, Yanwen; Lu, Xunwen

2008-01-01

To describe the epidemiology and re-employment outcomes of employees with industrial injuries and provide further information for the prevention of industrial injuries and work rehabilitation with the purpose of lower injury rate and cost savings. Learn about epidemiology and re-employment status by investigating 467 employees separately when in hospital and half a year after leaving hospital. The investigation form is designed according to the Classification Criterion of Employee's Casualty Accident (UDC658.382 GB6441-86) and local industrial injury status. Employees with industrial injuries have obvious regional characteristics in aspects such as sex composition, age, position of injury, injury causes, injury type, and vocation before suffering injury, level of education, degree of disability, employment wishes, and actual employment status. Industrial injury presents obvious characteristics in epidemiology. Therefore, it should take respective characteristics into consideration when conducting prevention of industrial injury and work rehabilitation.

The limitations of opportunistic epidemiology, pseudopod epidemiology.

PubMed

Kuller, Lewis H

2016-10-01

Epidemiology has been remarkably successful in the past in identifying the important agents of disease, the impact of the environment, both physical and social, and interrelationship with host susceptibility (genomics). Many of the advances in improving the health of individuals and populations have been the result of epidemiology studies that have identified the specific "agents" of disease and application of public health and preventive medicine. In recent years, large longitudinal studies have dominated epidemiology research, especially long incubation period chronic diseases. The initial hypotheses in these studies have been expanded by vertical extension studies using newer technologies to measure independent variables, vertical pseudopods, and additional studies of other diseases, horizontal pseudopods, of the original longitudinal study. Host susceptibility, i.e. genomics, has also become a prominent component of these longitudinal studies. The critical question addressed in this paper is whether these "pseudopod" epidemiology approaches have enhanced public health or generated a large number of studies of little impact.

Becoming the Framingham Study 1947–1950

PubMed Central

Oppenheimer, Gerald M.

2005-01-01

In the epidemiological imagination, the Framingham Heart Study has attained iconic status, both as the prototype of the cohort study and as a result of its scientific success. When the Public Health Service launched the study in 1947, epidemiological knowledge of coronary heart disease was poor, and epidemiology primarily involved the study of infectious disease. In constructing their investigation, Framingham’s initiators had to invent new approaches to epidemiological research. These scientific goals were heavily influenced by the contending institutional and personal interests buffeting the study. The study passed through vicissitudes and stages during its earliest years as its organizers grappled to define its relationship to medicine, epidemiology, and the local community. PMID:15798116

A trip to inner space: insights into salt balance from cosmonauts.

PubMed

Ortiz-Melo, David; Coffman, Thomas M

2013-01-08

The epidemiological association between high salt intake and hypertension is well established. However, in most patients, the specific defect causing salt-dependent hypertension cannot be discerned. In this issue of Cell Metabolism, Rakova and associates use an unprecedented study design to characterize long-term salt balance in humans (Rakova et al., 2012). Copyright © 2013 Elsevier Inc. All rights reserved.

[Current problems in the laboratory control of louse-borne typhus infection in Ukraine].

PubMed

Klymchuk, M D

1996-01-01

Surveys designed to study spread of typhus infection (persistent form and Brill's disease), and state of laboratory diagnosis in Ukraine showed an important role the laboratory diagnosis plays in the system of epidemiological surveillance aimed at preventing epidemic typhus. Main trends of activities on perfection of the system of laboratory control of the infection under present-day conditions are outlined.

[Use of area-level socioeconomic indicators in epidemiological research: experience in Spain and advancement opportunities].

PubMed

Domínguez-Berjón, María Felicitas; Rodríguez-Sanz, Maica; Marí-Dell'Olmo, Marc; Esnaola, Santiago; Prieto-Salceda, María Dolores; Duque, Ignacio; Rodrigo, María Pilar

2014-01-01

To determine the use of area-level socioeconomic indicators in epidemiological studies in Spain. We included studies analyzing the association of area-level socioeconomic indicators and health indicators in Spain published in peer-reviewed journals. An electronic search was conducted in PubMed-Medline, SCI-Expanded, SSCI, Embase, and the Spanish Medical Index (until December 31, 2012). A manual search was also conducted of the references of the selected studies. Each of the articles initially selected on the basis of the title and abstract was reviewed by two investigators. Information was obtained on the publication and methodology (design and study areas, information sources, health and socioeconomic indicators, and statistical analysis). We included 142 studies published since 1988 (58.4% since 2005). More than half (59.9%) were in English. The level of analysis was ecological in 73.2% and multilevel in 19.0%. The areas most frequently analyzed were census tracts (35 studies), especially within cities or autonomous regions, followed by the provinces (30 studies), mostly concerning Spain overall. The dependent variable most frequently analyzed was mortality and the socioeconomic dimension most commonly used was employment (71.1%). In the last decade in Spain, there has been an increase in the number of studies examining the association of area-level socioeconomic and health indicators, as well as in the complexity of design and analysis. Copyright © 2014 SESPAS. Published by Elsevier Espana. All rights reserved.

A Review of the Effects of Chronic Arsenic Exposure on Adverse Pregnancy Outcomes.

PubMed

Milton, Abul H; Hussain, Sumaira; Akter, Shahnaz; Rahman, Mijanur; Mouly, Tafzila A; Mitchell, Kane

2017-05-23

Exposure to arsenic has a number of known detrimental health effects but impact on pregnancy outcomes is not as widely recognized. This narrative review examines existing epidemiological evidence investigating the association between arsenic exposure via drinking water and adverse pregnancy outcomes. We reviewed published epidemiological studies from around the world on impact of chronic arsenic exposure on spontaneous abortion, stillbirth, neonatal death, post neonatal death, low birth weight and preterm baby. Plausible mechanisms of arsenic toxicity causing adverse pregnancy outcomes were also determined through literature review. There is convincing evidence to support the association between high inorganic arsenic exposure (>50 ppb) and spontaneous abortion, stillbirth and low birth weight. Limitations of certain studies include study design, small sample size, recall constraints and exposure assessment. There needs to be further research investigating the dose metered impact of arsenic exposure on pregnancy outcomes. Further research on impact of low-moderate arsenic concentration exposure on pregnancy outcomes will allow for appropriate public health policy recommendations.

PERSONAL MEASURES OF POWER-FREQUENCY MAGNETIC FIELD EXPOSURE AMONG MEN FROM AN INFERTILITY CLINIC: DISTRIBUTION, TEMPORAL VARIABILITY AND CORRELATION WITH THEIR FEMALE PARTNERS' EXPOSURE

PubMed Central

Lewis, Ryan C.; Hauser, Russ; Maynard, Andrew D.; Neitzel, Richard L.; Wang, Lu; Kavet, Robert; Morey, Patricia; Ford, Jennifer B.; Meeker, John D.

2016-01-01

Power-frequency magnetic field exposure science as it relates to men and couples have not been explored despite the advantage of this information in the design and interpretation of reproductive health epidemiology studies. This analysis examined the distribution and temporal variability of exposures in men, and the correlation of exposures within couples using data from a longitudinal study of 25 men and their female partners recruited from an infertility clinic. The average and 90th percentile demonstrated fair to good reproducibility, whereas the maximum showed poor reproducibility over repeated sampling days, each separated by a median of 4.6 weeks. Average magnetic field exposures were also strongly correlated within couples, suggesting that one partner's data could be used as a surrogate in the absence of data from the other for this metric. Environment was also an important effect modifier in these explored matters. These issues should be considered in future relevant epidemiology studies. PMID:26705359

A Review of the Effects of Chronic Arsenic Exposure on Adverse Pregnancy Outcomes

PubMed Central

Milton, Abul H.; Hussain, Sumaira; Akter, Shahnaz; Rahman, Mijanur; Mouly, Tafzila A.; Mitchell, Kane

2017-01-01

Exposure to arsenic has a number of known detrimental health effects but impact on pregnancy outcomes is not as widely recognized. This narrative review examines existing epidemiological evidence investigating the association between arsenic exposure via drinking water and adverse pregnancy outcomes. We reviewed published epidemiological studies from around the world on impact of chronic arsenic exposure on spontaneous abortion, stillbirth, neonatal death, post neonatal death, low birth weight and preterm baby. Plausible mechanisms of arsenic toxicity causing adverse pregnancy outcomes were also determined through literature review. There is convincing evidence to support the association between high inorganic arsenic exposure (>50 ppb) and spontaneous abortion, stillbirth and low birth weight. Limitations of certain studies include study design, small sample size, recall constraints and exposure assessment. There needs to be further research investigating the dose metered impact of arsenic exposure on pregnancy outcomes. Further research on impact of low–moderate arsenic concentration exposure on pregnancy outcomes will allow for appropriate public health policy recommendations. PMID:28545256

Creating an African HIV Clinical Research and Prevention Trials Network: HIV Prevalence, Incidence and Transmission

PubMed Central

Kamali, Anatoli; Price, Matt A.; Lakhi, Shabir; Karita, Etienne; Inambao, Mubiana; Sanders, Eduard J.; Anzala, Omu; Latka, Mary H.; Bekker, Linda-Gail; Kaleebu, Pontiano; Asiki, Gershim; Ssetaala, Ali; Ruzagira, Eugene; Allen, Susan; Farmer, Paul; Hunter, Eric; Mutua, Gaudensia; Makkan, Heeran; Tichacek, Amanda; Brill, Ilene K.; Fast, Pat; Stevens, Gwynn; Chetty, Paramesh; Amornkul, Pauli N.; Gilmour, Jill

2015-01-01

HIV epidemiology informs prevention trial design and program planning. Nine clinical research centers (CRC) in sub-Saharan Africa conducted HIV observational epidemiology studies in populations at risk for HIV infection as part of an HIV prevention and vaccine trial network. Annual HIV incidence ranged from below 2% to above 10% and varied by CRC and risk group, with rates above 5% observed in Zambian men in an HIV-discordant relationship, Ugandan men from Lake Victoria fishing communities, men who have sex with men, and several cohorts of women. HIV incidence tended to fall after the first three months in the study and over calendar time. Among suspected transmission pairs, 28% of HIV infections were not from the reported partner. Volunteers with high incidence were successfully identified and enrolled into large scale cohort studies. Over a quarter of new cases in couples acquired infection from persons other than the suspected transmitting partner. PMID:25602351

The success of pharmacogenomics in moving genetic association studies from bench to bedside: study design and implementation of precision medicine in the post-GWAS era.

PubMed

Ritchie, Marylyn D

2012-10-01

Pharmacogenomics is emerging as a popular type of study for human genetics in recent years. This is primarily due to the many success stories and high potential for translation to clinical practice. In this review, the strengths and limitations of pharmacogenomics are discussed as well as the primary epidemiologic, clinical trial, and in vitro study designs implemented. A brief discussion of molecular and analytic approaches will be reviewed. Finally, several examples of bench-to-bedside clinical implementations of pharmacogenetic traits will be described. Pharmacogenomics continues to grow in popularity because of the important genetic associations identified that drive the possibility of precision medicine.

Molecular characterization of measles viruses in Turkey (2010-2011): first report of genotype D9 involved in an outbreak in 2011.

PubMed

Kalaycioglu, Atila T; Baykal, Atakan; Guldemir, Dilek; Bakkaloglu, Zekiye; Korukluoglu, Gulay; Coskun, Aslihan; Torunoglu, Mehmet Ali; Ertek, Mustafa; Durmaz, Riza

2013-12-01

Genetic characterization of measles viruses (MVs) combined with acquisition of epidemiologic information is essential for measles surveillance programs used in determining transmission pathways. This study describes the molecular characterization of 26 MV strains (3 from 2010, 23 from 2011) obtained from urine or throat swabs harvested from patients in Turkey. MV RNA samples (n = 26) were subjected to sequence analysis of 450 nucleotides comprising the most variable C-terminal region of the nucleoprotein (N) gene. Phylogenetic analysis revealed 20 strains from 2011 belonged to genotype D9, 3 to D4, 2 strains from 2010 to genotype D4 and 1 to genotype B3. This study represents the first report describing the involvement of MV genotype D9 in an outbreak in Turkey. The sequence of the majority of genotype D9 strains was identical to those identified in Russia, Malaysia, Japan, and the UK. Despite lack of sufficient epidemiologic information, the presence of variants observed following phylogenetic analysis suggested that exposure to genotype D9 might have occurred due to importation more than once. Phylogenetic analysis of five genotype D4 strains revealed the presence of four variants. Epidemiological information and phylogenetic analysis suggested that three genotype D4 strains and one genotype B3 strain were associated with importation. This study suggests the presence of pockets of unimmunized individuals making Turkey susceptible to outbreaks. Continuing molecular surveillance of measles strains in Turkey is essential as a means of acquiring epidemiologic information to define viral transmission patterns and determine the effectiveness of measles vaccination programs designed to eliminate this virus. © 2013 Wiley Periodicals, Inc.

Hypertension-misattributed kidney disease in African Americans.

PubMed

Skorecki, Karl L; Wasser, Walter G

2013-01-01

Lipkowitz et al. extend the African American Study of Kidney Disease and Hypertension to the level of genetic epidemiology, in a case-control study design. Analysis of genotypes at the APOL1 kidney disease risk region supports a paradigm shift in which genetic risk is proximate to both kidney disease and hypertension. The findings mandate urgency in clarifying mechanisms whereby APOL1 region risk variants interact with environmental triggers to cause progressive kidney disease accompanied by dangerous hypertension.

Environmental and Genetic Contributors to Hypospadias: A Review of the Epidemiologic Evidence

PubMed Central

Carmichael, Suzan L.; Shaw, Gary M.; Lammer, Edward J.

2012-01-01

This review evaluates current knowledge related to trends in the prevalence of hypospadias, the association of hypospadias with endocrine-disrupting exposures, and the potential contribution of genetic susceptibility to its etiology. The review focuses on epidemiologic evidence. Increasing prevalence of hypospadias has been observed, but such increases tend to be localized to specific regions or time periods. Thus, generalized statements that hypospadias is increasing are unsupported. Due to limitations of study designs and inconsistent results, firm conclusions cannot be made regarding the association of endocrine-disrupting exposures with hypospadias. Studies with more rigorous study designs (e.g., larger and more detailed phenotypes) and exposure assessment that encompasses more breadth as well as depth (e.g., specific endocrine-related chemicals) will be critical to make better inferences about these important environmental exposures. Many candidate genes for hypospadias have been identified, but few of them have been examined to an extent that enables solid conclusions. Further studies are needed that include larger sample sizes, comparison groups that are more representative of the populations from which the cases were derived, phenotype-specific analyses, and more extensive exploration of variants. In conclusion, examining the associations of environmental and genetic factors with hypospadias remain important areas of inquiry, although our actual understanding of their contribution to hypospadias risk in humans is currently limited. PMID:22678668

Sequence-Based Typing of Legionella pneumophila Serogroup 1 Offers the Potential for True Portability in Legionellosis Outbreak Investigation

PubMed Central

Gaia, Valeria; Fry, Norman K.; Harrison, Timothy G.; Peduzzi, Raffaele

2003-01-01

Seven gene loci of Legionella pneumophila serogroup 1 were analyzed as potential epidemiological typing markers to aid in the investigation of legionella outbreaks. The genes chosen included four likely to be selectively neutral (acn, groES, groEL, and recA) and three likely to be under selective pressure (flaA, mompS, and proA). Oligonucleotide primers were designed to amplify 279- to 763-bp fragments from each gene. Initial sequence analysis of the seven loci from 10 well-characterized isolates of L. pneumophila serogroup 1 gave excellent reproducibility (R) and epidemiological concordance (E) values (R = 1.00; E = 1.00). The three loci showing greatest discrimination and nucleotide variation, flaA, mompS, and proA, were chosen for further study. Indices of discrimination (D) were calculated using a panel of 79 unrelated isolates. Single loci gave D values ranging from 0.767 to 0.857, and a combination of all three loci resulted in a D value of 0.924. When all three loci were combined with monoclonal antibody subgrouping, the D value was 0.971. Sequence-based typing of L. pneumophila serogroup 1 using only three loci is epidemiologically concordant and highly discriminatory and has the potential to become the new “gold standard” for the epidemiological typing of L. pneumophila. PMID:12843023

Statistical methods for studying disease subtype heterogeneity.

PubMed

Wang, Molin; Spiegelman, Donna; Kuchiba, Aya; Lochhead, Paul; Kim, Sehee; Chan, Andrew T; Poole, Elizabeth M; Tamimi, Rulla; Tworoger, Shelley S; Giovannucci, Edward; Rosner, Bernard; Ogino, Shuji

2016-02-28

A fundamental goal of epidemiologic research is to investigate the relationship between exposures and disease risk. Cases of the disease are often considered a single outcome and assumed to share a common etiology. However, evidence indicates that many human diseases arise and evolve through a range of heterogeneous molecular pathologic processes, influenced by diverse exposures. Pathogenic heterogeneity has been considered in various neoplasms such as colorectal, lung, prostate, and breast cancers, leukemia and lymphoma, and non-neoplastic diseases, including obesity, type II diabetes, glaucoma, stroke, cardiovascular disease, autism, and autoimmune disease. In this article, we discuss analytic options for studying disease subtype heterogeneity, emphasizing methods for evaluating whether the association of a potential risk factor with disease varies by disease subtype. Methods are described for scenarios where disease subtypes are categorical and ordinal and for cohort studies, matched and unmatched case-control studies, and case-case study designs. For illustration, we apply the methods to a molecular pathological epidemiology study of alcohol intake and colon cancer risk by tumor LINE-1 methylation subtypes. User-friendly software to implement the methods is publicly available. Copyright © 2015 John Wiley & Sons, Ltd.

Risk factors for age-related maculopathy.

PubMed

Connell, Paul P; Keane, Pearse A; O'Neill, Evelyn C; Altaie, Rasha W; Loane, Edward; Neelam, Kumari; Nolan, John M; Beatty, Stephen

2009-01-01

Age-related maculopathy (ARM) is the leading cause of blindness in the elderly. Although beneficial therapeutic strategies have recently begun to emerge, much remains unclear regarding the etiopathogenesis of this disorder. Epidemiologic studies have enhanced our understanding of ARM, but the data, often conflicting, has led to difficulties with drawing firm conclusions with respect to risk for this condition. As a consequence, we saw a need to assimilate the published findings with respect to risk factors for ARM, through a review of the literature appraising results from published cross-sectional studies, prospective cohort studies, case series, and case control studies investigating risk for this condition. Our review shows that, to date, and across a spectrum of epidemiologic study designs, only age, cigarette smoking, and family history of ARM have been consistently demonstrated to represent risk for this condition. In addition, genetic studies have recently implicated many genes in the pathogenesis of age-related maculopathy, including Complement Factor H, PLEKHA 1, and LOC387715/HTRA1, demonstrating that environmental and genetic factors are important for the development of ARM suggesting that gene-environment interaction plays an important role in the pathogenesis of this condition.

Genotyping of Mycobacterium tuberculosis: application in epidemiologic studies

PubMed Central

Kato-Maeda, Midori; Metcalfe, John Z.; Flores, Laura

2014-01-01

Genotyping is used to track specific isolates of Mycobacterium tuberculosis in a community. It has been successfully used in epidemiologic research (termed ‘molecular epidemiology’) to study the transmission dynamics of TB. In this article, we review the genetic markers used in molecular epidemiologic studies including the use of whole-genome sequencing technology. We also review the public health application of molecular epidemiologic tools. PMID:21366420

The "Pathological Gambling and Epidemiology" (PAGE) study program: design and fieldwork.

PubMed

Meyer, Christian; Bischof, Anja; Westram, Anja; Jeske, Christine; de Brito, Susanna; Glorius, Sonja; Schön, Daniela; Porz, Sarah; Gürtler, Diana; Kastirke, Nadin; Hayer, Tobias; Jacobi, Frank; Lucht, Michael; Premper, Volker; Gilberg, Reiner; Hess, Doris; Bischof, Gallus; John, Ulrich; Rumpf, Hans-Jürgen

2015-03-01

The German federal states initiated the "Pathological Gambling and Epidemiology" (PAGE) program to evaluate the public health relevance of pathological gambling. The aim of PAGE was to estimate the prevalence of pathological gambling and cover the heterogenic presentation in the population with respect to comorbid substance use and mental disorders, risk and protective factors, course aspects, treatment utilization, triggering and maintenance factors of remission, and biological markers. This paper describes the methodological details of the study and reports basic prevalence data. Two sampling frames (landline and mobile telephone numbers) were used to generate a random sample from the general population consisting of 15,023 individuals (ages 14 to 64) completing a telephone interview. Additionally, high-risk populations have been approached in gambling locations, via media announcements, outpatient addiction services, debt counselors, probation assistants, self-help groups and specialized inpatient treatment facilities. The assessment included two steps: (1) a diagnostic interview comprising the gambling section of the Composite International Diagnostic Interview (CIDI) for case finding; (2) an in-depth clinical interview with participants reporting gambling problems. The in-depth clinical interview was completed by 594 participants, who were recruited from the general or high-risk populations. The program provides a rich epidemiological database which is available as a scientific use file. Copyright © 2015 John Wiley & Sons, Ltd.

Incorporating microbiota data into epidemiologic models: examples from vaginal microbiota research.

PubMed

van de Wijgert, Janneke H; Jespers, Vicky

2016-05-01

Next generation sequencing and quantitative polymerase chain reaction technologies are now widely available, and research incorporating these methods is growing exponentially. In the vaginal microbiota (VMB) field, most research to date has been descriptive. The purpose of this article is to provide an overview of different ways in which next generation sequencing and quantitative polymerase chain reaction data can be used to answer clinical epidemiologic research questions using examples from VMB research. We reviewed relevant methodological literature and VMB articles (published between 2008 and 2015) that incorporated these methodologies. VMB data have been analyzed using ecologic methods, methods that compare the presence or relative abundance of individual taxa or community compositions between different groups of women or sampling time points, and methods that first reduce the complexity of the data into a few variables followed by the incorporation of these variables into traditional biostatistical models. To make future VMB research more clinically relevant (such as studying associations between VMB compositions and clinical outcomes and the effects of interventions on the VMB), it is important that these methods are integrated with rigorous epidemiologic methods (such as appropriate study designs, sampling strategies, and adjustment for confounding). Crown Copyright © 2016. Published by Elsevier Inc. All rights reserved.

Asphalt and risk of cancer in man.

PubMed Central

Chiazze, L; Watkins, D K; Amsel, J

1991-01-01

Epidemiological publications regarding the carcinogenic potential of asphalt (bitumen) are reviewed. In 1984 the International Agency for Research on Cancer (IARC) stated that there is "inadequate evidence that bitumens alone are carcinogenic to humans." They did, however, conclude that animal data provided sufficient evidence for the carcinogenicity of certain extracts of steam refined and air refined bitumens. In the absence of data on man, IARC considered it reasonable to regard chemicals with sufficient evidence of carcinogenicity in animals as if they presented a carcinogenic risk to man. Epidemiological data for man accumulated since the IARC report do not fulfil the criteria for showing a causal association between exposure to asphalt and development of cancer. The studies cited all suffer from a lack of data on exposure or potential confounders, which are necessary to establish whether or not such an association may or may not exist. In view of the evidence (or lack thereof) regarding asphalt today, an appropriate public health attitude suggests at least that action be taken to protect those working with asphalt by monitoring the workplace, taking whatever steps are possible to minimise exposures and to inform workers of potential hazards. At the same time, a need exists for well designed analytical epidemiological studies to determine whether a risk of cancer in man exists from exposure to asphalt. PMID:1878310

Addressing refugee health through evidence-based policies: a case study.

PubMed

Thiel de Bocanegra, Heike; Carter-Pokras, Olivia; Ingleby, J David; Pottie, Kevin; Tchangalova, Nedelina; Allen, Sophia I; Smith-Gagen, Julie; Hidalgo, Bertha

2018-06-01

The cumulative total of persons forced to leave their country for fear of persecution or organized violence reached an unprecedented 24.5 million by the end of 2015. Providing equitable access to appropriate health services for these highly diverse newcomers poses challenges for receiving countries. In this case study, we illustrate the importance of translating epidemiology into policy to address the health needs of refugees by highlighting examples of what works as well as identifying important policy-relevant gaps in knowledge. First, we formed an international working group of epidemiologists and health services researchers to identify available literature on the intersection of epidemiology, policy, and refugee health. Second, we created a synopsis of findings to inform a recommendation for integration of policy and epidemiology to support refugee health in the United States and other high-income receiving countries. Third, we identified eight key areas to guide the involvement of epidemiologists in addressing refugee health concerns. The complexity and uniqueness of refugee health issues, and the need to develop sustainable management information systems, require epidemiologists to expand their repertoire of skills to identify health patterns among arriving refugees, monitor access to appropriately designed health services, address inequities, and communicate with policy makers and multidisciplinary teams. Copyright © 2017 Elsevier Inc. All rights reserved.

77 FR 5804 - Statement of Organization, Functions, and Delegations of Authority

Federal Register 2010, 2011, 2012, 2013, 2014

2012-02-06

... organizations; (5) plans, directs, and conducts epidemiologic and evaluative investigations and interventions to... support to NCCDPHP scientific authors; (9) designs, develops, and coordinates the publication of print and... avenues; (3) designs, coordinates, and funds regional and national surveillance systems and population...

Epidemiological Study of Patients of Road Traffic Injuries Attending Emergency Department of a Trauma Center in New Delhi

PubMed Central

Misra, Puneet; Majumdar, Anindo; Misra, Mahesh Chandra; Kant, Shashi; Gupta, Sanjeev Kumar; Gupta, Amit; Kumar, Subodh

2017-01-01

Background and Aims: There is paucity of data regarding some of the lesser known contextual and epidemiological factors with respect to road traffic injuries (RTIs). The objective was to study the epidemiological profile of RTI victims attending an emergency department of a tertiary care trauma center. Methods: The present study was a hospital-based cross-sectional study conducted in the emergency department of a tertiary care trauma center in New Delhi. All patients of RTI attending the emergency department during the designated data collection days were included in the study. Patients brought dead were excluded from the study. A semi-structured interview schedule was developed for collecting data on various domains such as sociodemographic characteristics, vehicle-related factors, accident site-related factors, personal protection measures, contextual factors, and prehospital care-related factors. Results: A total of 984 patients and informants were approached and finally data of 900 participants were analyzed after excluding those who refused participation and those for whom incomplete data were available. Out of 900 RTI victims, 756 were male (84.0%) and 144 (16.0%) were female. Mean age of the victims was 32.7 years. Most of the victims, i.e., 377 out of 900 (41.9%) were occupants rather than drivers. Majority of victim's vehicle meeting accidents were motorized two-wheelers (53.4%), and majority of the colliding vehicle was a four-wheeler (39.3*). Helmet use was found to be low (63.3%), but seat belt use was particularly low (32.4%). Most accidents (28%) happened between midnight and 6 A.M. More than half of the victims were in a hurry on the day of the accident. An ambulance was used to transport the victims in only 14.6% cases. Conclusion: In road traffic accidents some lesser known epidemiological data were generated that may be useful in defining preventive measures. PMID:29142380

Rationale and design of the PREFERS (Preserved and Reduced Ejection Fraction Epidemiological Regional Study) Stockholm heart failure study: an epidemiological regional study in Stockholm county of 2.1 million inhabitants.

PubMed

Linde, Cecilia; Eriksson, Maria J; Hage, Camilla; Wallén, Håkan; Persson, Bengt; Corbascio, Matthias; Lundeberg, Joakim; Maret, Eva; Ugander, Martin; Persson, Hans

2016-10-01

Heart failure (HF) with preserved (HFpEF) or reduced (HFrEF) ejection fraction is associated with poor prognosis and quality of life. While the incidence of HFrEF is declining and HF treatment is effective, HFpEF is increasing, with no established therapy. PREFERS Stockholm is an epidemiological study with the aim of improving clinical care and research in HF and to find new targets for drug treatment in HFpEF (https://internwebben.ki.se/sites/default/files/20150605_4d_research_appendix_final.pdf). Patients with new-onset HF (n = 2000) will be characterized at baseline and after 1-year follow-up by standardized protocols for clinical evaluation, echocardiography, and ECG. In one subset undergoing elective coronary bypass surgery (n = 100) and classified according to LV function, myocardial biopsies will be collected during surgery, and cardiac magnetic resonance (CMR) imaging will be performed at baseline and after 1 year. Blood and tissue samples will be stored in a biobank. We will characterize and compare new-onset HFpEF and HFrEF patients regarding clinical findings and cardiac imaging, genomics, proteomics, and transcriptomics from blood and cardiac biopsies, and by established biomarkers of fibrosis, inflammation, haemodynamics, haemostasis, and thrombosis. The data will be explored by state-of-the-art bioinformatics methods to investigate gene expression patterns, sequence variation, DNA methylation, and post-translational modifications, and using systems biology approaches including pathway and network analysis. In this epidemiological HF study with biopsy studies in a subset of patients, we aim to identify new biomarkers of disease progression and to find pathophysiological mechanisms to support explorations of new treatment regimens for HFpEF. © 2016 The Authors. European Journal of Heart Failure © 2016 European Society of Cardiology.

A systematic review of human and animal leptospirosis in the Pacific Islands reveals pathogen and reservoir diversity

PubMed Central

Goarant, Cyrille; Benschop, Jackie

2018-01-01

Background The Pacific Islands have environmental conditions highly favourable for transmission of leptospirosis, a neglected zoonosis with highest incidence in the tropics, and Oceania in particular. Recent reports confirm the emergence and outbreaks of leptospirosis in the Pacific Islands, but the epidemiology and drivers of transmission of human and animal leptospirosis are poorly documented, especially in the more isolated and less developed islands. Methodology/Principal findings We conducted a systematic review of human and animal leptospirosis within 25 Pacific Islands (PIs) in Polynesia, Melanesia, Micronesia, as well as Easter Island and Hawaii. We performed a literature search using four international databases for articles published between January 1947 and June 2017. We further included grey literature available on the internet. We identified 148 studies describing leptospirosis epidemiology, but the number of studies varied significantly between PIs. No data were available from four PIs. Human leptospirosis has been reported from 13 PIs, with 63% of all studies conducted in Hawaii, French Polynesia and New Caledonia. Animal leptospirosis has been investigated in 19 PIs and from 14 host species, mainly pigs (18% of studies), cattle (16%) and dogs (11%). Only 13 studies provided information on both human and animal leptospirosis from the same location. Serology results were highly diverse in the region, both in humans and animals. Conclusions/Significance Our study suggests that, as in other tropical regions, leptospirosis is widespread in the PIs while showing some epidemiological heterogeneity. Data are scarce or absent from many PIs. Rodents, cattle, pigs and dogs are all likely to be important carriers, but the relative importance of each animal species in human infection needs to be clarified. Epidemiological surveys with appropriate sampling design, pathogen typing and data analysis are needed to improve our understanding of transmission patterns and to develop effective intervention strategies. PMID:29758037

Evaluation of a Phylogenetic Marker Based on Genomic Segment B of Infectious Bursal Disease Virus: Facilitating a Feasible Incorporation of this Segment to the Molecular Epidemiology Studies for this Viral Agent.

PubMed

Alfonso-Morales, Abdulahi; Rios, Liliam; Martínez-Pérez, Orlando; Dolz, Roser; Valle, Rosa; Perera, Carmen L; Bertran, Kateri; Frías, Maria T; Ganges, Llilianne; Díaz de Arce, Heidy; Majó, Natàlia; Núñez, José I; Pérez, Lester J

2015-01-01

Infectious bursal disease (IBD) is a highly contagious and acute viral disease, which has caused high mortality rates in birds and considerable economic losses in different parts of the world for more than two decades and it still represents a considerable threat to poultry. The current study was designed to rigorously measure the reliability of a phylogenetic marker included into segment B. This marker can facilitate molecular epidemiology studies, incorporating this segment of the viral genome, to better explain the links between emergence, spreading and maintenance of the very virulent IBD virus (vvIBDV) strains worldwide. Sequences of the segment B gene from IBDV strains isolated from diverse geographic locations were obtained from the GenBank Database; Cuban sequences were obtained in the current work. A phylogenetic marker named B-marker was assessed by different phylogenetic principles such as saturation of substitution, phylogenetic noise and high consistency. This last parameter is based on the ability of B-marker to reconstruct the same topology as the complete segment B of the viral genome. From the results obtained from B-marker, demographic history for both main lineages of IBDV regarding segment B was performed by Bayesian skyline plot analysis. Phylogenetic analysis for both segments of IBDV genome was also performed, revealing the presence of a natural reassortant strain with segment A from vvIBDV strains and segment B from non-vvIBDV strains within Cuban IBDV population. This study contributes to a better understanding of the emergence of vvIBDV strains, describing molecular epidemiology of IBDV using the state-of-the-art methodology concerning phylogenetic reconstruction. This study also revealed the presence of a novel natural reassorted strain as possible manifest of change in the genetic structure and stability of the vvIBDV strains. Therefore, it highlights the need to obtain information about both genome segments of IBDV for molecular epidemiology studies.

How much, how long, what, and where: air pollution exposure assessment for epidemiologic studies of respiratory disease.

PubMed

Brauer, Michael

2010-05-01

Epidemiology has played an important role in the understanding of air pollution as a risk factor for respiratory disease and in the evidence base for air quality standards. With the widespread availability of genetic information and increasingly sophisticated measurements of molecular markers of adverse effects, there is a need for more specific and precise assessment of exposure to maximize the potential information to be derived from epidemiologic studies. Here advances in air pollution exposure assessment and their applications to studies of respiratory disease are reviewed, with a focus on recent studies of traffic-related air pollution and asthma. Although continuous measurements of personal exposures for all study subjects for a complete study period might be considered the desired "gold standard" for exposure, this is rarely, if ever, achieved due to feasibility constraints. Given this, exposure is typically estimated using models. Recent applications of geospatial (e.g., land use regression) models to studies of respiratory disease have made possible new study designs focused on spatial variability in exposure within urban areas and have provided new insights into the potential role of traffic-related air pollution (TRAP) as a risk factor for the development of childhood asthma. Substantial uncertainty remains, however, regarding what agent(s) within TRAP might be responsible for the observed associations. Future research will require increasing the specificity of exposure assessment to identify the potential roles of individual air pollution components, to elucidate potential mechanisms, and to facilitate studies of mixtures and gene-air pollution interactions.

Epidemiology of Injuries in Stand-Up Paddle Boarding

PubMed Central

Furness, James; Olorunnife, Olayinka; Schram, Ben; Climstein, Mike; Hing, Wayne

2017-01-01

Background: Stand-up paddle boarding (SUP) is a recreational activity and sport that has grown exponentially, with participation increasing from 1.1 million in 2010 to 2.8 million in 2014 in the United States alone. Despite this growth in participation, SUP remains underresearched with regard to injury epidemiology. Purpose: To investigate injury epidemiology (severity, location, type, mechanism) in SUP. Study Design: Descriptive epidemiology study. Methods: An open-source online survey was administered to active SUP participants internationally. The survey captured information relevant to demographics, participation, and injury history over the past 12 months. Results: Of 240 participants included in the data analysis, 67.1% were males, and 54.6% were involved in competition. Participants spent a mean 192.6 ± 179.5 hours participating in SUP per year, most commonly for fun and fitness (43.3%) at the beach or bay (63.0%). A total of 95 participants had sustained at least 1 injury. A total of 161 injuries were recorded, resulting in an injury rate of 3.63 (95% CI, 3.04-4.16) per 1000 hours of SUP. The shoulder/upper arm was the most frequently injured body location, accounting for 32.9% of all injuries, followed by the lower back (14.3%) and the elbow/forearm (11.8%). The most common injury types were to muscle/tendon (50.4%), joint/ligament (22.6%), and skin (14.2%). Endurance paddling was the most frequently reported mechanism of injury (34.5%), followed by contact with a paddler’s own board (20.1%) and sprint paddling (9.3%). Key risk factors for sustaining an injury were age >46 years, competitive status, and participating for >4.8 hours/week, as well as using SUP for racing. Conclusion: This is the first study to report injury epidemiology for SUP. It is evident that both sexes participate in SUP for fun, fitness, and competition. With regard to injuries, the shoulder, lower back, and elbow are the most injury prone; older age, competitive status, and longer hours of participation all influenced the chance of injury. Findings from this study provide the foundation for injury prevention strategies. PMID:28638840

Turkey’s Epidemiological and Demographic Transitions: 1931-2013

PubMed Central

Bakar, Coşkun; Oymak, Sibel; Maral, Işıl

2017-01-01

Background: The causes of death have changed with regard to the epidemiological and demographic events in society. There is no evidence of prior research into the epidemiological transition in Turkey. This transition in Turkey should be observed starting with the Ottoman Empire period (19th to early 20th century). However, information about the Ottoman Empire is quite limited. Aims: To discuss the epidemiological and demographic transitions in Turkey, using demographic, educational and urbanization data in our present study. Study Design: A descriptive archive study. Methods: Mortality statistics dating from 1931 and published by the Turkish Statistical Institute were analysed, and the causes of death were coded and classified according to ICD-10. Other data were obtained from the published reports and studies regarding the issue. Results: In the 1930s, Turkey’s life expectancy was low (aged 40 years), fertility and mortality rates were high (respectively 45% and 31%), and the main causes of death were infectious diseases. Nowadays, life expectancy is close to 80 years, the total fertility rate has dropped to 2.1 per woman, and the main causes of death are chronic diseases and cancer. The population rate in the urban areas has increased steadily from 24.2% in 1927 to 77.3% in 2012. level of education has also increased during this period. In 1935, less than 10% of women were literate, and in 2013 90% were literate. Qualitative and quantitative increase have been observed in the presentation and access of healthcare services compared to the early years of the Republic. Conclusion: Turkey has been undergoing a modernization period in the last 200 years, and it is believed that the epidemiological and demographic transitions result from this period. This process has led to urbanization and an increase in the level of education, as well as a decrease in premature deaths, lower fertility rates, and an increase in the elderly population and chronic diseases. It is therefore our conclusion that Turkey needs policies regarding the elderly population and the management of chronic diseases. PMID:28443561

Improving the Linkages between Air Pollution Epidemiology and Quantitative Risk Assessment

PubMed Central

Bell, Michelle L.; Walker, Katy; Hubbell, Bryan

2011-01-01

Background: Air pollution epidemiology plays an integral role in both identifying the hazards of air pollution as well as supplying the risk coefficients that are used in quantitative risk assessments. Evidence from both epidemiology and risk assessments has historically supported critical environmental policy decisions. The extent to which risk assessors can properly specify a quantitative risk assessment and characterize key sources of uncertainty depends in part on the availability, and clarity, of data and assumptions in the epidemiological studies. Objectives: We discuss the interests shared by air pollution epidemiology and risk assessment communities in ensuring that the findings of epidemiological studies are appropriately characterized and applied correctly in risk assessments. We highlight the key input parameters for risk assessments and consider how modest changes in the characterization of these data might enable more accurate risk assessments that better represent the findings of epidemiological studies. Discussion: We argue that more complete information regarding the methodological choices and input data used in epidemiological studies would support more accurate risk assessments—to the benefit of both disciplines. In particular, we suggest including additional details regarding air quality, demographic, and health data, as well as certain types of data-rich graphics. Conclusions: Relatively modest changes to the data reported in epidemiological studies will improve the quality of risk assessments and help prevent the misinterpretation and mischaracterization of the results of epidemiological studies. Such changes may also benefit epidemiologists undertaking meta-analyses. We suggest workshops as a way to improve the dialogue between the two communities. PMID:21816702

The Dresden Predictor Study of anxiety and depression: objectives, design, and methods.

PubMed

Trumpf, Julia; Vriends, Noortje; Meyer, Andrea H; Becker, Eni S; Neumer, Simon-Peter; Margraf, Jürgen

2010-09-01

The present report describes the objectives, design, and methods of the Dresden Predictor Study (DPS) of anxiety and depression, a prospective epidemiological study investigating anxiety disorders and depression in 3,065 young German women (18-25 years of age). The DPS consists of a baseline and one follow-up investigation separated by approximately 17 months. At both time points, respondents were diagnosed according to the Diagnostic and Statistical Manual of Mental Disorders, 4th Edition (DSM-IV) using an extended German version of the Anxiety Disorders Interview Schedule (ADIS-IV-L). In addition to diagnostic assessment, respondents completed a battery of self-report questionnaires that provided detailed information about potential predictors of disorders and a comprehensive dimensional assessment of psychopathology. Results on both response bias in the baseline investigation and effects of dropout at follow-up are presented, and strengths and limitations of the study design are discussed.

Design and analysis issues in gene and environment studies

PubMed Central

2012-01-01

Both nurture (environmental) and nature (genetic factors) play an important role in human disease etiology. Traditionally, these effects have been thought of as independent. This perspective is ill informed for non-mendelian complex disorders which result as an interaction between genetics and environment. To understand health and disease we must study how nature and nurture interact. Recent advances in human genomics and high-throughput biotechnology make it possible to study large numbers of genetic markers and gene products simultaneously to explore their interactions with environment. The purpose of this review is to discuss design and analytic issues for gene-environment interaction studies in the “-omics” era, with a focus on environmental and genetic epidemiological studies. We present an expanded environmental genomic disease paradigm. We discuss several study design issues for gene-environmental interaction studies, including confounding and selection bias, measurement of exposures and genotypes. We discuss statistical issues in studying gene-environment interactions in different study designs, such as choices of statistical models, assumptions regarding biological factors, and power and sample size considerations, especially in genome-wide gene-environment studies. Future research directions are also discussed. PMID:23253229

Design and analysis issues in gene and environment studies.

PubMed

Liu, Chen-yu; Maity, Arnab; Lin, Xihong; Wright, Robert O; Christiani, David C

2012-12-19

Both nurture (environmental) and nature (genetic factors) play an important role in human disease etiology. Traditionally, these effects have been thought of as independent. This perspective is ill informed for non-mendelian complex disorders which result as an interaction between genetics and environment. To understand health and disease we must study how nature and nurture interact. Recent advances in human genomics and high-throughput biotechnology make it possible to study large numbers of genetic markers and gene products simultaneously to explore their interactions with environment. The purpose of this review is to discuss design and analytic issues for gene-environment interaction studies in the "-omics" era, with a focus on environmental and genetic epidemiological studies. We present an expanded environmental genomic disease paradigm. We discuss several study design issues for gene-environmental interaction studies, including confounding and selection bias, measurement of exposures and genotypes. We discuss statistical issues in studying gene-environment interactions in different study designs, such as choices of statistical models, assumptions regarding biological factors, and power and sample size considerations, especially in genome-wide gene-environment studies. Future research directions are also discussed.

A Systematic Bayesian Integration of Epidemiological and Genetic Data

PubMed Central

Lau, Max S. Y.; Marion, Glenn; Streftaris, George; Gibson, Gavin

2015-01-01

Genetic sequence data on pathogens have great potential to inform inference of their transmission dynamics ultimately leading to better disease control. Where genetic change and disease transmission occur on comparable timescales additional information can be inferred via the joint analysis of such genetic sequence data and epidemiological observations based on clinical symptoms and diagnostic tests. Although recently introduced approaches represent substantial progress, for computational reasons they approximate genuine joint inference of disease dynamics and genetic change in the pathogen population, capturing partially the joint epidemiological-evolutionary dynamics. Improved methods are needed to fully integrate such genetic data with epidemiological observations, for achieving a more robust inference of the transmission tree and other key epidemiological parameters such as latent periods. Here, building on current literature, a novel Bayesian framework is proposed that infers simultaneously and explicitly the transmission tree and unobserved transmitted pathogen sequences. Our framework facilitates the use of realistic likelihood functions and enables systematic and genuine joint inference of the epidemiological-evolutionary process from partially observed outbreaks. Using simulated data it is shown that this approach is able to infer accurately joint epidemiological-evolutionary dynamics, even when pathogen sequences and epidemiological data are incomplete, and when sequences are available for only a fraction of exposures. These results also characterise and quantify the value of incomplete and partial sequence data, which has important implications for sampling design, and demonstrate the abilities of the introduced method to identify multiple clusters within an outbreak. The framework is used to analyse an outbreak of foot-and-mouth disease in the UK, enhancing current understanding of its transmission dynamics and evolutionary process. PMID:26599399

[Socio-epidemiological and cultural aspects of cutaneous leishmaniasis: conceptions, attitudes and practices in the populations of Tierralta and Valencia (Cordoba, Colombia)].

PubMed

Patiño-Londoño, Sandra Yaneth; Salazar, Lina Marcela; Acero, Catalina Tovar; Bernal, Iván Darío Vélez

2017-01-01

This article focuses on the conceptions, attitudes and practices of the inhabitants from four villages (veredas) in Tierralta and Valencia (Cordoba, Colombia), who have suffered from or are aware of the existence of cutaneous leishmaniasis. A mixed methodology was implemented based in a qualitative design using interviews and focus groups (n=45) and an epidemiological design which included applying the Montenegro test (n=251), uncovering suspected cases of cutaneous leishmaniasis in humans, (n=5) and applying epidemiological surveys (n=409). Among the results, a lack of knowledge regarding the vector was found; although respondents could identify the Lutzomyia (known as "alú"), they did not correlate it with cutaneous leishmaniasis. In addition, traditional home treatments were more frequently used, increasing the underrecording of cases. With respect to healthcare personnel, flaws in diagnosis and treatment were found, which reinforces adherence to home treatments. This scenario calls for a reflection upon the challenges of the health care system in relation to the interventions of health personnel in communities situated in endemic areas.

Epidemiologic studies of electric and magnetic fields and cancer: strategies for extending knowledge.

PubMed Central

Savitz, D A

1993-01-01

Epidemiologic research concerning electric and magnetic fields in relation to cancer has focused on the potential etiologic roles of residential exposure on childhood cancer and occupational exposure on adult leukemia and brain cancer. Future residential studies must concentrate on exposure assessment that is enhanced by developing models of historical exposure, assessment of the relation between magnetic fields and wire codes, and consideration of alternate exposure indices. Study design issues deserving attention include possible biases in random digit dialing control selection, consideration of the temporal course of exposure and disease, and acquisition of the necessary information to assess the potential value of ecologic studies. Highest priorities are comprehensive evaluation of exposure patterns and sources and examination of the sociology and geography of residential wire codes. Future occupational studies should also concentrate on improved exposure assessment with increased attention to nonutility worker populations and development of historical exposure indicators that are superior to job titles alone. Potential carcinogens in the workplace that could act as confounders need to be more carefully examined. The temporal relation between exposure and disease and possible effect modification by other workplace agents should be incorporated into future studies. The most pressing need is for measurement of exposure patterns in a variety of worker populations and performance of traditional epidemiologic evaluations of cancer occurrence. The principal source of bias toward the null is nondifferential misclassification of exposure with improvements expected to enhance any true etiologic association that is present. Biases away from the null might include biased control selection in residential studies and chemical carcinogens acting as confounders in occupational studies. PMID:8206046

Meat consumption and risk of lung cancer: evidence from observational studies

PubMed Central

Yang, W. S.; Wong, M. Y.; Vogtmann, E.; Tang, R. Q.; Xie, L.; Yang, Y. S.; Wu, Q. J.; Zhang, W.; Xiang, Y. B.

2012-01-01

Background A number of epidemiological studies have reported inconsistent findings on the association between meat consumption and lung cancer. Design We therefore conducted a systematic review and meta-analysis to investigate the relationship between meat consumption and lung cancer risk in epidemiological studies. Results Twenty-three case–control and 11 cohort studies were included. All studies adjusted for smoking or conducted in never smokers. The summary relative risks (RRs) of lung cancer for the highest versus lowest intake categories were 1.35 (95% confidence interval (CI) 1.08–1.69) for total meat, 1.34 (95% CI 1.18–1.52) for red meat, and 1.06 (95% CI 0.90–1.25) for processed meat. An inverse association was found between poultry intake and lung cancer (RR = 0.91, 95% CI 0.85–0.97), but not for total white meat (RR = 1.06, 95% CI 0.82–1.37) or fish (RR = 1.01, 95% CI 0.96–1.07). Conclusions The relationship between meat intake and lung cancer risk appears to depend on the types of meat consumed. A high intake of red meat may increase the risk of lung cancer by about 35%, while a high intake of poultry decreases the risk by about 10%. More well-designed cohort studies on meat mutagens or heme iron, meat cooking preferences, and doneness level are needed to fully characterize this meat–lung cancer association. PMID:22855553

The use of ultrasound measurements in environmental epidemiological studies of air pollution and fetal growth

PubMed Central

Smarr, Melissa M.; Vadillo-Ortega, Felipe; Castillo-Castrejon, Marisol; O’Neill, Marie S.

2015-01-01

Purpose of review Recently, several international research groups have suggested that studies about environmental contaminants and adverse pregnancy outcomes should be designed to elucidate potential underlying biological mechanisms. The purpose of this review is to examine the epidemiological studies addressing maternal exposure to air pollutants and fetal growth during gestation as assessed by ultrasound measurements. Recent findings The six studies published to date found that exposure to certain ambient air pollutants during pregnancy is negatively associated with the growth rates and average attained size of fetal parameters belonging to the growth profile. Fetal parameters may respond to maternal air pollution exposures uniquely, and this response may vary by pollutant and timing of gestational exposure. Current literature suggests that mean changes in head circumference, abdominal circumference, femur length, and biparietal diameter are negatively associated with early-pregnancy exposures to ambient and vehicle-related air pollution. Summary The use of more longitudinal studies, employing ultrasound measures to assess fetal outcomes, may assist with the better understanding of mechanisms responsible for air pollution-related pregnancy outcomes. PMID:23399571

Evaluating psychiatric case-control studies using the STROBE (STrengthening the Reporting of OBservational Studies in Epidemiology) statement.

PubMed

Goi, Pedro Domingues; Goi, Julia Domingues; Cordini, Kariny Larissa; Ceresér, Keila Mendes; Rocha, Neusa Sica da

2014-01-01

Case-control studies are important in developing clinical and public health knowledge. The STROBE statement (STrengthening the Reporting of OBservational Studies in Epidemiology) was developed to establish a checklist of items that should be included in articles reporting observational studies. Our aim was to analyze whether the psychiatric case-control articles published in Brazilian journals with CAPES Qualis rating B1/B2 in 2009 conformed with the STROBE statement. Descriptive study on psychiatric papers published in Brazilian journals, within the Postgraduate Medical Program on Psychiatry, at Universidade Federal do Rio Grande do Sul. All psychiatric case-control studies from Brazilian Qualis B1/B2 journals of psychiatry, neurology and public health in 2009 were analyzed. The four most specific items of the STROBE statement were used to evaluate whether these studies fitted within the case-control parameters: 1) selection of cases and controls; 2) controlling for bias; 3) statistical analysis; and 4) presentation of results. Sixteen case-control studies were identified, of which eleven (68.75%) were in psychiatry-focused journals. From analysis using the STROBE statement, all of the articles conformed with item 1; two (12.5%) completely conformed with item 2; none completely conformed with item 3; and only three (18.8%) conformed with item 4. The case-control studies analyzed here did not completely conform with the four STROBE statement items for case-control design. In view of the inadequate methodology of the published studies, these findings justify focusing on research and methodology and expanding the investigations on adherence of studies to their designs.

Integrating Survey and Molecular Approaches to Better Understand Wildlife Disease Ecology

PubMed Central

Cowled, Brendan D.; Ward, Michael P.; Laffan, Shawn W.; Galea, Francesca; Garner, M. Graeme; MacDonald, Anna J.; Marsh, Ian; Muellner, Petra; Negus, Katherine; Quasim, Sumaiya; Woolnough, Andrew P.; Sarre, Stephen D.

2012-01-01

Infectious wildlife diseases have enormous global impacts, leading to human pandemics, global biodiversity declines and socio-economic hardship. Understanding how infection persists and is transmitted in wildlife is critical for managing diseases, but our understanding is limited. Our study aim was to better understand how infectious disease persists in wildlife populations by integrating genetics, ecology and epidemiology approaches. Specifically, we aimed to determine whether environmental or host factors were stronger drivers of Salmonella persistence or transmission within a remote and isolated wild pig (Sus scrofa) population. We determined the Salmonella infection status of wild pigs. Salmonella isolates were genotyped and a range of data was collected on putative risk factors for Salmonella transmission. We a priori identified several plausible biological hypotheses for Salmonella prevalence (cross sectional study design) versus transmission (molecular case series study design) and fit the data to these models. There were 543 wild pig Salmonella observations, sampled at 93 unique locations. Salmonella prevalence was 41% (95% confidence interval [CI]: 37–45%). The median Salmonella DICE coefficient (or Salmonella genetic similarity) was 52% (interquartile range [IQR]: 42–62%). Using the traditional cross sectional prevalence study design, the only supported model was based on the hypothesis that abundance of available ecological resources determines Salmonella prevalence in wild pigs. In the molecular study design, spatial proximity and herd membership as well as some individual risk factors (sex, condition score and relative density) determined transmission between pigs. Traditional cross sectional surveys and molecular epidemiological approaches are complementary and together can enhance understanding of disease ecology: abundance of ecological resources critical for wildlife influences Salmonella prevalence, whereas Salmonella transmission is driven by local spatial, social, density and individual factors, rather than resources. This enhanced understanding has implications for the control of diseases in wildlife populations. Attempts to manage wildlife disease using simplistic density approaches do not acknowledge the complexity of disease ecology. PMID:23071552

Current practice of epidemiology in Africa: highlights of the 3rd conference of the African epidemiological association and 1st conference of the Cameroon society of epidemiology, Yaoundé, Cameroon, 2014

PubMed Central

Nkwescheu, Armand Seraphin; Fokam, Joseph; Tchendjou, Patrice; Nji, Akindeh; Ngouakam, Hermann; Andre, Bita Fouda; Joelle, Sobngwi; Uzochukwu, Benjamin; Akinroye, Kingsley; Mbacham, Wilfred; Colizzi, Vittorio; Leke, Rose; Victora, Cesar

2015-01-01

As the study of disease occurrence and health indicators in human populations, Epidemiology is a dynamic field that evolves with time and geographical context. In order to update African health workers on current epidemiological practices and to draw awareness of early career epidemiologists on concepts and opportunities in the field, the 3rd African Epidemiology Association and the 1st Cameroon Society of Epidemiology Conference was organized in June 2-6, 2014 at the Yaoundé Mont Febe Hotel, in Cameroon. Under the theme«Practice of Epidemiology in Africa: Stakes, Challenges and Perspectives», the conference attracted close to five hundred guest and participants from all continents. The two main programs were the pre-conference course for capacity building of African Early Career epidemiologists, and the conference itself, providing a forum for scientific exchanges on recent epidemiological concepts, encouraging the use of epidemiological methods in studying large disease burden and neglected tropical diseases; and highlighting existing opportunities. PMID:26523191

Current practice of epidemiology in Africa: highlights of the 3rd conference of the African epidemiological association and 1st conference of the Cameroon society of epidemiology, Yaoundé, Cameroon, 2014.

PubMed

Nkwescheu, Armand Seraphin; Fokam, Joseph; Tchendjou, Patrice; Nji, Akindeh; Ngouakam, Hermann; Andre, Bita Fouda; Joelle, Sobngwi; Uzochukwu, Benjamin; Akinroye, Kingsley; Mbacham, Wilfred; Colizzi, Vittorio; Leke, Rose; Victora, Cesar

2015-01-01

As the study of disease occurrence and health indicators in human populations, Epidemiology is a dynamic field that evolves with time and geographical context. In order to update African health workers on current epidemiological practices and to draw awareness of early career epidemiologists on concepts and opportunities in the field, the 3(rd) African Epidemiology Association and the 1st Cameroon Society of Epidemiology Conference was organized in June 2-6, 2014 at the Yaoundé Mont Febe Hotel, in Cameroon. Under the theme«Practice of Epidemiology in Africa: Stakes, Challenges and Perspectives», the conference attracted close to five hundred guest and participants from all continents. The two main programs were the pre-conference course for capacity building of African Early Career epidemiologists, and the conference itself, providing a forum for scientific exchanges on recent epidemiological concepts, encouraging the use of epidemiological methods in studying large disease burden and neglected tropical diseases; and highlighting existing opportunities.

[Scientific, practical and educational aspects of clinical epidemiology].

PubMed

Briko, N I

2012-01-01

This article defines clinical epidemiology and describes its goal and objectives. The author claims that clinical epidemiology is a section of epidemiology which underlies the development of evidence-based standards for diagnostics, treatment and prevention and helps to select the appropriate algorithm for each clinical case. The study provides a comprehensive overview of the relationship between clinical epidemiology and evidence-based medicine. Epidemiological research is shown to be methodological basis of clinical epidemiology and evidence-based medicine with randomized controlled trials being the "gold standard" for obtaining reliable data. The key stages in the history of clinical epidemiology are discussed and further development of clinical epidemiology and the integration of courses on clinical epidemiology in education is outlined for progress in medical research and health care practice.

Nuclear health and safety

DOE Office of Scientific and Technical Information (OSTI.GOV)

Glenn, J.

1991-02-01

There has been concern over the Department of Energy's (DOE) dual role of producing nuclear weapons and assessing the potential health hazards associated with operating its facilities has raised questions about DOE's ability to effectively manage its health and health effects (epidemiology) research programs. In March 1990, the secrecy of Energy announced several initiatives to address these concerns. These initiatives include, among others, the development of an occupational health and epidemiology program, the transfer of long-term health effects' studies to the Department of Health and Human Services (HHS), the establishment of an advisory committee to oversee DOE's environmental, safety, andmore » health activities, and the design of a data base to store and retrieve health data. This paper provides a brief description of DOE's initiatives, including their status as of December 1990 and general observations of these initiatives.« less

Mild Cognitive Dysfunction: An Epidemiological Perspective with an Emphasis on African Americans

PubMed Central

Unverzagt, Frederick W.; Gao, Sujuan; Lane, Kathleen A.; Callahan, Christopher; Ogunniyi, Adesola; Baiyewu, Olusegun; Gureje, Oye; Hall, Kathleen S.; Hendrie, Hugh C.

2009-01-01

In this review, we begin with a historical accounting of the evolution of the concept of mild cognitive dysfunction including nomenclature and criteria from Kral to Petersen. A critical analysis of the main elements relating to assessment and diagnosis of mild cognitive dysfunction are described. Methodological limitations in design, measurement, and characterization, especially as they relate to older African Americans, are identified. Data from a 15-year longitudinal study of community-dwelling, African Americans in Indianapolis indicate 23% prevalence of all-cause mild cognitive dysfunction with approximately 25% progressing to dementia in 2 years and another 25% reverting to normal in the same interval. Factors contributing to this longitudinal variability in outcome are reviewed including the role of medical health factors. We close with suggestions for next steps in the epidemiological research of mild cognitive impairment. PMID:18004008

hprt mutant frequencies, nonpulmonary malignancies, and domestic radon exposure: "postmortem" analysis of an interesting hypothesis.

PubMed

Ruttenber, A J; Harrison, L T; Baron, A; McClure, D; Glanz, J; Quillin, R; O'Neill, J P; Sullivan, L; Campbell, J; Nicklas, J A

2001-01-01

The hypothesis that exposure to domestic radon raises the risk for leukemia and other nonpulmonary cancers has been proposed and tested in a number of epidemiologic studies over the past decade. During this period, interest in this hypothesis was heightened by evidence of increased frequencies of mutations at the hypoxanthine guanine phosphoribosyl transferase (hprt) gene in persons exposed to domestic radon (Bridges BA et al. [1991]: Lancet 337:1187-1189). An extension of this study (Cole J et al. [lsqb[1996]: Radiat Res 145:61-69) and two independent studies (Albering HJ et al. [1992[: Lancet 340:739; Albering HJ et al. [1994[: Lancet 344:750-751) found that hprt mutant frequency was not correlated with domestic radon exposure, and two well-designed epidemiologic studies showed no evidence of a relation between radon exposure and leukemia in children or adults. In this report, we present additional data from a study of Colorado high school students showing no correlation between domestic radon exposure and hprt mutant frequency. We use reanalyses of previous studies of radon and hprt mutant frequency to identify problems with this assay as a biomarker for domestic radon exposure and to illustrate difficulties in interpreting the statistical data. We also show with analyses of combined data sets that there is no support for the hypothesis that domestic radon exposure elevates hprt mutant frequency. Taken together, the scientific evidence provides a useful example of the problems associated with analyzing and interpreting data that link environmental exposures, biomarkers, and diseases in epidemiologic studies. Copyright 2001 Wiley-Liss, Inc.

Prevalence of laceration injuries in professional and amateur rugby union: a systematic review and meta-analysis

PubMed Central

Driscoll, Heather; Kilner, Karen; James, David

2017-01-01

Background Studded footwear can cause severe lacerations in rugby union; the prevalence of these injuries is currently unknown. Objective To summarise the skin and laceration injury prevalence in published epidemiological studies and to investigate any differences in skin injury risk between amateur and professional players. Design Systematic literature review and meta-analysis of epidemiological studies. Data sources PubMed, Web of Science, Scopus and Ovid. Eligibility criteria for selecting studies Prospective, epidemiological studies published in English after 1995, measuring a minimum of 400 match or 900 training exposure hours. Participants should be adult rugby union players (amateur or professional). The study should report a separate skin or laceration injury category and provide sufficient detail to calculate injury prevalence within this category. Results Twelve studies were included. Mean skin injury prevalence during matches was 2.4 injuries per 1000 exposure hours; during training sessions, the prevalence was 0.06 injuries per 1000 exposure hours. Skin injuries accounted for 5.3% of match injuries and 1.7% of training injuries. Skin injury risk was similar for amateur compared with professional players during matches (OR: 0.63, p=0.46.), but higher during training sessions (OR: 9.24, p=0.02). Conclusions The skin injury prevalence of 2.4 injuries per 1000 exposure hours is equivalent to one time-loss injury sustained during matches per team, per season. Amateur players are more likely to sustain skin injuries during training sessions than professional players. There is a need for more studies observing injuries among amateur players. Trial registration number PROSPERO CRD42015024027. PMID:28761716

Overview of Recent Marine and Freshwater Recreational Epidemiology Studies and Their Findings

EPA Science Inventory

Overview of Recent Marine and Freshwater Recreational Epidemiology Studies and Their Findings Timothy J. Wade, Elizabeth A. Sams, Rich Haugland, Alfred P. Dufour The National Epidemiologic and Environmental Assessment of Recreational Water Study was conducted to address aspects...

[Biological markers in epidemiology: concepts, applications, perspectives (part I)].

PubMed

Hoffmann, W; Latza, U; Ahrens, W; Greiser, K H; Kroke, A; Nieters, A; Schulze, M B; Steiner, M; Terschüren, C; Wjst, M

2002-02-01

The inclusion of biomarkers in epidemiological research provides new possibilities for exposure assessment and the study of early structural or functional changes and pre-clinical stages of diseases. At the same time issues of validity, reliability, and quality control as well as logistics require special attention. Usually epidemiological studies become more expensive with regard to time and cost. Interdisciplinary collaboration between epidemiology, basic research, and laboratory research is crucial. A prerequisite for this collaboration are agreements on definitions, methods and procedures. The definition of "biomarker" and a description of previous uses of biomarkers in epidemiological studies are presented in the first part of this paper. The second part addresses genetic markers and markers of individual sensitivity and susceptibility. We will end with a discussion about the possible future of biomarkers in epidemiology.

Pauci- and Multibacillary Leprosy: Two Distinct, Genetically Neglected Diseases

PubMed Central

Gaschignard, Jean; Grant, Audrey Virginia; Thuc, Nguyen Van; Orlova, Marianna; Cobat, Aurélie; Huong, Nguyen Thu; Ba, Nguyen Ngoc; Thai, Vu Hong; Abel, Laurent; Schurr, Erwin; Alcaïs, Alexandre

2016-01-01

After sustained exposure to Mycobacterium leprae, only a subset of exposed individuals develops clinical leprosy. Moreover, leprosy patients show a wide spectrum of clinical manifestations that extend from the paucibacillary (PB) to the multibacillary (MB) form of the disease. This “polarization” of leprosy has long been a major focus of investigation for immunologists because of the different immune response in these two forms. But while leprosy per se has been shown to be under tight human genetic control, few epidemiological or genetic studies have focused on leprosy subtypes. Using PubMed, we collected available data in English on the epidemiology of leprosy polarization and the possible role of human genetics in its pathophysiology until September 2015. At the genetic level, we assembled a list of 28 genes from the literature that are associated with leprosy subtypes or implicated in the polarization process. Our bibliographical search revealed that improved study designs are needed to identify genes associated with leprosy polarization. Future investigations should not be restricted to a subanalysis of leprosy per se studies but should instead contrast MB to PB individuals. We show the latter approach to be the most powerful design for the identification of genetic polarization determinants. Finally, we bring to light the important resource represented by the nine-banded armadillo model, a unique animal model for leprosy. PMID:27219008

Functional Characterization of Promoter Variants of the Adiponectin Gene Complemented by Epidemiological Data

PubMed Central

Laumen, Helmut; Saningong, Akuma D.; Heid, Iris M.; Hess, Jochen; Herder, Christian; Claussnitzer, Melina; Baumert, Jens; Lamina, Claudia; Rathmann, Wolfgang; Sedlmeier, Eva-Maria; Klopp, Norman; Thorand, Barbara; Wichmann, H.-Erich; Illig, Thomas; Hauner, Hans

2009-01-01

OBJECTIVE Adiponectin (APM1, ACDC) is an adipocyte-derived protein with downregulated expression in obesity and insulin-resistant states. Several potentially regulatory single nucleotide polymorphisms (SNPs) within the APM1 gene promoter region have been associated with circulating adiponectin levels. None of them have been functionally characterized in adiponectin-expressing cells. Hence, we investigated three SNPs (rs16861194, rs17300539, and rs266729) for their influence on adiponectin promoter activity and their association with circulating adiponectin levels. RESEARCH DESIGN AND METHODS Basal and rosiglitazone-induced promoter activity of different SNP combinations (haplotypes) was analyzed in 3T3-L1 adipocytes using luciferase reporter gene assays and DNA binding studies comparing all possible APM1 haplotypes. This functional approach was complemented with analysis of epidemiological population-based data of 1,692 participants of the MONICA/KORA S123 cohort and 696 participants from the KORA S4 cohort for SNP and haplotype association with circulating adiponectin levels. RESULTS Major to minor allele replacements of the three SNPs revealed significant effects on promoter activity in luciferase assays. Particularly, a minor variant in rs16861194 resulted in reduced basal and rosiglitazone-induced promoter activity and hypoadiponectinemia in the epidemiological datasets. The haplotype with the minor allele in all three SNPs showed a complete loss of promoter activity, and no subject carried this haplotype in either of the epidemiological samples (combined P value for statistically significant difference from a random sample was 0.006). CONCLUSIONS Our results clearly demonstrate that promoter variants associated with hypoadiponectinemia in humans substantially affect adiponectin promoter activity in adipocytes. Our combination of functional experiments with epidemiological data overcomes the drawback of each approach alone. PMID:19074982

A proof of concept for epidemiological research using structured reporting with pulmonary embolism as a use case.

PubMed

Daniel, Pinto Dos Santos; Sonja, Scheibl; Gordon, Arnhold; Aline, Maehringer-Kunz; Christoph, Düber; Peter, Mildenberger; Roman, Kloeckner

2018-05-10

This paper studies the possibilities of an integrated IT-based workflow for epidemiological research in pulmonary embolism using freely available tools and structured reporting. We included a total of 521 consecutive cases which had been referred to the radiology department for computed tomography pulmonary angiography (CTPA) with suspected pulmonary embolism (PE). Free-text reports were transformed into structured reports using a freely available IHE-MRRT-compliant reporting platform. D-dimer values were retrieved from the hospitals laboratory results system. All information was stored in the platform's database and visualized using freely available tools. For further analysis, we directly accessed the platform's database with an advanced analytics tool (RapidMiner). We were able developed an integrated workflow for epidemiological statistics from reports obtained in clinical routine. The report data allowed for automated calculation of epidemiological parameters. Prevalence of pulmonary embolism was 27.6%. The mean age in patients with and without pulmonary embolism did not differ (62.8 years and 62.0 years, respectively, p=0.987). As expected, there was a significant difference in mean D-dimer values (10.13 mg/L FEU and 3.12 mg/L FEU, respectively, p<0.001). Structured reporting can make data obtained from clinical routine more accessible. Designing practical workflows is feasible using freely available tools and allows for the calculation of epidemiological statistics on a near real-time basis. Therefore, radiologists should push for the implementation of structured reporting in clinical routine. Advances in knowledge: Theoretical benefits of structured reporting have long been discussed, but practical implementation demonstrating those benefits has been lacking. Here we present a first experience providing proof that structured reporting will make data from clinical routine more accessible.

Chronic pain epidemiology – where do lifestyle factors fit in?

PubMed Central

Torrance, Nicola; Smith, Blair H

2013-01-01

Chronic pain is common and complex and has a large impact on individuals and society. Good epidemiological pain data provide key information on the use of resources (both in general practice and in specialist clinics), insight into factors that lead to or favour chronicity and the design of interventions aimed at reducing or preventing the effects of chronic pain. This review aims to highlight the important factors associated with chronic pain, including those factors which are amenable to lifestyle intervention. PMID:26516524

Air pollution, inflammation and preterm birth in Mexico City: study design and methods.

PubMed

O'Neill, Marie S; Osornio-Vargas, Alvaro; Buxton, Miatta A; Sánchez, Brisa N; Rojas-Bracho, Leonora; Castillo-Castrejon, Marisol; Mordhukovich, Irina B; Brown, Daniel G; Vadillo-Ortega, Felipe

2013-03-15

Preterm birth is one of the leading causes of perinatal mortality and is associated with long-term adverse health consequences for surviving infants. Preterm birth rates are rising worldwide, and no effective means for prevention currently exists. Air pollution exposure may be a significant cause of prematurity, but many published studies lack the individual, clinical data needed to elucidate possible biological mechanisms mediating these epidemiological associations. This paper presents the design of a prospective study now underway to evaluate those mechanisms in a cohort of pregnant women residing in Mexico City. We address how air quality may act together with other factors to induce systemic inflammation and influence the duration of pregnancy. Data collection includes: biomarkers relevant to inflammation in cervico-vaginal exudate and peripheral blood, along with full clinical information, pro-inflammatory cytokine gene polymorphisms and air pollution data to evaluate spatial and temporal variability in air pollution exposure. Samples are collected on a monthly basis and participants are followed for the duration of pregnancy. The data will be used to evaluate whether ambient air pollution is associated with preterm birth, controlling for other risk factors. We will evaluate which time windows during pregnancy are most influential in the air pollution and preterm birth association. In addition, the epidemiological study will be complemented with a parallel toxicology invitro study, in which monocytic cells will be exposed to air particle samples to evaluate the expression of biomarkers of inflammation. Copyright © 2012 Elsevier B.V. All rights reserved.

Air pollution, inflammation and preterm birth in Mexico City: Study design and methods

PubMed Central

O’Neill, Marie S.; Osornio-Vargas, Alvaro; Buxton, Miatta A.; Sanchez, Brisa N.; Rojas-Bracho, Leonora; Castillo-Castrejon, Marisol; Mordhukovich, Irina B.; Brown, Daniel G.; Vadillo-Ortega, Felipe

2012-01-01

Preterm birth is one of the leading causes of perinatal mortality and is associated with long-term adverse health consequences for surviving infants. Preterm birth rates are rising worldwide, and no effective means for prevention currently exists. Air pollution exposure may be a significant cause of prematurity, but many published studies lack the individual, clinical data needed to elucidate possible biological mechanisms mediating these epidemiological associations. This paper presents the design of a prospective study now underway to evaluate those mechanisms in a cohort of pregnant women residing in Mexico City. We address how air quality may act together with other factors to induce systemic inflammation and influence the duration of pregnancy. Data collection includes: biomarkers relevant to inflammation in cervico-vaginal exudate and peripheral blood, along with full clinical information, pro-inflammatory cytokine gene polymorphisms and air pollution data to evaluate spatial and temporal variability in air pollution exposure. Samples are collected on a monthly basis and participants are followed for the duration of pregnancy. The data will be used to evaluate whether ambient air pollution is associated with preterm birth, controlling for other risk factors. We will evaluate which time windows during pregnancy are most influential in the air pollution and preterm birth association. In addition, the epidemiological study will be complemented with a parallel toxicology invitro study, in which monocytic cells will be exposed to air particle samples to evaluate the expression of biomarkers of inflammation. PMID:23177781

Sequencing Strategies for Population and Cancer Epidemiology Studies (SeqSPACE) Webinar Series

Cancer.gov

The Sequencing Strategies for Population and Cancer Epidemiology Studies (SeqSPACE) Webinar Series provides an opportunity for our grantees and other interested individuals to share lessons learned and practical information regarding the application of next generation sequencing to cancer epidemiology studies.

The Biomonitoring, Environmental Epidemiology, and Short-Lived Chemicals (BEES-C) Instrument for Assessing Study Quality

EPA Science Inventory

Environmental epidemiology studies can be an effective means to assess impacts on human health from exposure to environmental stressors. Exposure scenarios are often extremely complex and proper assessment is critical for interpreting epidemiological study results. Biomarkers are...

ICS-II USA research design and methodology.

PubMed

Rana, H; Andersen, R M; Nakazono, T T; Davidson, P L

1997-05-01

The purpose of the WHO-sponsored International Collaborative Study of Oral Health Outcomes (ICS-II) was to provide policy-markers and researchers with detailed, reliable, and valid data on the oral health situation in their countries or regions, together with comparative data from other dental care delivery systems. ICS-II used a cross-sectional design with no explicit control groups or experimental interventions. A standardized methodology was developed and tested for collecting and analyzing epidemiological, sociocultural, economic, and delivery system data. Respondent information was obtained by household interviews, and clinical examinations were conducted by calibrated oral epidemiologists. Discussed are the sampling design characteristics for the USA research locations, response rates, samples size for interview and oral examination data, weighting procedures, and statistical methods. SUDAAN was used to adjust variance calculations, since complex sampling designs were used.

Risk of bias and confounding of observational studies of Zika virus infection: A scoping review of research protocols.

PubMed

Reveiz, Ludovic; Haby, Michelle M; Martínez-Vega, Ruth; Pinzón-Flores, Carlos E; Elias, Vanessa; Smith, Emma; Pinart, Mariona; Broutet, Nathalie; Becerra-Posada, Francisco; Aldighieri, Sylvain; Van Kerkhove, Maria D

2017-01-01

Given the severity and impact of the current Zika virus (ZIKV) outbreak in the Americas, numerous countries have rushed to develop research studies to assess ZIKV and its potential health consequences. In an effort to ensure that studies are comprehensive, both internally and externally valid, and with reliable results, the World Health Organization, the Pan American Health Organization, Institut Pasteur, the networks of Fiocruz, the Consortia for the Standardization of Influenza Seroepidemiology (CONSISE) and the International Severe Acute Respiratory and Emerging Infection Consortium (ISARIC) have generated six standardized clinical and epidemiological research protocols and questionnaires to address key public health questions on ZIKV. We conducted a systematic search of ongoing study protocols related to ZIKV research. We analyzed the content of protocols of 32 cohort studies and 13 case control studies for systematic bias that could produce erroneous results. Additionally we aimed to characterize the risks of bias and confounding in observational studies related to ZIKV and to propose ways to minimize them, including the use of six newly standardized research protocols. Observational studies of ZIKV face an array of challenges, including measurement of exposure and outcomes (microcephaly and Guillain-Barré Syndrome). Potential confounders need to be measured where known and controlled for in the analysis. Selection bias due to non-random selection is a significant issue, particularly in the case-control design, and losses to follow-up is equally important for the cohort design. Observational research seeking to answer key questions on the ZIKV should consider these restrictions and take precautions to minimize bias in an effort to provide reliable and valid results. Utilization of the standardized research protocols developed by the WHO, PAHO, Institut Pasteur, and CONSISE will harmonize the key methodological aspects of each study design to minimize bias at different stages of the study. Biases need to be considered by researchers implementing the standardized protocols as well as by users of observational epidemiological studies of ZIKV.

Epidemiological studies of cognitive impairment and dementia across Eastern and Middle European countries (epidemiology of dementia in Eastern and Middle European Countries).

PubMed

Kiejna, A; Frydecka, D; Adamowski, T; Bickel, H; Reynish, E; Prince, M; Caracciolo, B; Fratiglioni, L; Georges, J

2011-02-01

To determine the availability and the consistency of prevalence findings of epidemiological studies on cognitive impairment and dementia conducted in Eastern and Middle Europe. We adopted a stepwise multimethod study approach consisting of iterative literature searches for epidemiological articles published between 1990 and 2006 and subsequent data analyses of published material, reanalyses of existing accessible epidemiological data sets and expert inquiries in Eastern and Middle European countries. Systematic computer-assisted searches used the keywords: "dementia", "Alzheimer", "cognitive impairment", "incidence", "prevalence", "epidemiology" in combination with the name of the relevant countries or "Europe" in English and Polish language. We supplemented the literature search with a review of the references in the articles that were identified during the initial search. We were able to find few regional and country-specific epidemiological studies of various kinds (population-based, cohort, cross-sectional studies) and conducted on different restricted population groups of patients (from neurological units, out-patients units, residential homes). No studies were identified from most of the countries taken under consideration and the ones we found were characterized by an immense diversity with a considerable degree of clinical and methodological variations. The few studies that there are suggest prevalence rates of dementia in Eastern Europe similar to those in Western Europe. There is strong need for epidemiological studies in Eastern and Middle Europe, as well as for greater coordination and standardization of methods to improve the quality and comparability of epidemiological data to determine the prevalences' rates of dementia in all the EU countries. Copyright © 2010 John Wiley & Sons, Ltd.

[Biology and culture: a dimension of collaboration between anthropology and epidemiology].

PubMed

Song, Leiming; Wang, Ning

2016-01-01

Biology is the important basis of epidemiological study. Based on biology, psychology, social and cultural factors can influence human's health and disease incidence. The medical mode has changed from "biomedical mode" to "bio-psycho-social medical model" , but culture factor was neglected somewhat during this process, so paying attention to culture factor in anthropologic study and using it as biologic basis in epidemiologic study might be a dimension of collaboration between of anthropology and epidemiology.

Update on the pathogenesis and treatment of childhood-onset systemic lupus erythematosus.

PubMed

Couture, Julie; Silverman, Earl D

2016-09-01

This article will provide an update of studies published in the last year regarding epidemiology, pathogenesis, major disease manifestations and outcomes, and therapies in childhood-onset systemic lupus erythematosus (cSLE). Recent studies on cSLE epidemiology supported previous findings that cSLE patients have more severe disease and tend to accumulate damage rapidly. Lupus nephritis remains frequent and is still a significant cause of morbidity and mortality. In the past year unfortunately there were no new reproducible, biomarker studies to help direct therapy of renal disease. However, some progress was made in neuropsychiatric disease assessment, with a new and promising automated test to screen for cognitive dysfunction reported. There were no prospective interventional treatment trials designed for patients with cSLE published in the last year, but some studies involving children are currently active and might improve the therapeutic options for patients with cSLE. There is a need to get a better understanding of pathogenesis and identify new biomarkers in cSLE to more accurately predict outcomes. New insights into characterization of different clinical manifestations may enable to optimize individual interventions and influence the prognosis.

Epidemiologic evidence for an association between gasoline and kidney cancer.

PubMed Central

Enterline, P E; Viren, J

1985-01-01

A recent animal experiment suggests that gasoline exposure may be a cause of human kidney cancer. This is a literature review to see whether there is any epidemiologic support for these animal findings. Trends and geographic patterns in gasoline consumption and kidney cancer mortality are moderately supportive of a relationship, although this cannot be considered important evidence for a causal relationship. Most other ecological correlations are not supportive of a relationship. Eleven oil refinery populations and one population of petroleum products distribution workers have been studied. These studies taken as a group do not appear to support the notion of a relationship between gasoline exposure and kidney cancer. However, most were not designed or analyzed with this hypothesis in mind. An examination of these data which attempts to consider the ages of the populations studied provides some evidence of a small kidney cancer excess among older workers or among workers exposed for long periods. Because of the importance of gasoline and the potential for exposure by the public further study of exposed populations is needed. PMID:4085434

Epidemiology of inflammatory bowel disease in Málaga: incidence rate and follow-up of a cohort diagnosed between 2007-2008.

PubMed

Cueto Torreblanca, Ignacio; Camargo Camero, Raquel; Andrade Bellido, Raúl; Romero Pérez, Eduardo; Alcaín Martínez, Guillermo

2017-08-01

The incidence of inflammatory bowel disease (IBD) in Spain has been traditionally lower than in Northern European countries. Recent epidemiological studies have found that these differences are diminishing. This study estimates the incidence of IBD in Málaga (Spain), a city in Southern Spain and relates its results to those found in our neighboring countries. This was a prospective study designed to collect new cases diagnosed during the period from 2007-2008 and follow up these patients. Incidence is expressed as number of patients per 100,000 population per year. The population distribution found in the European Collaborative Study was used to standardize incidence rates. The gross incidence rate of IBD in Málaga is 9/105, the standardized incidence rate is 12.3/105 (9.7-15.6). These data are similar to those found in our surroundings, although a higher incidence rate for Crohn's disease (CD) as compared to ulcerative colitis (UC) was found. The clinical characteristics and outcomes of our patients do not differ significantly from those described for other populations.

Spatial and Temporal Epidemiology of Nephropathia Epidemica Incidence and Hantavirus Seroprevalence in Rodent Hosts: Identification of the Main Environmental Factors in Europe.

PubMed

Monchatre-Leroy, E; Crespin, L; Boué, F; Marianneau, P; Calavas, D; Hénaux, V

2017-08-01

In Europe, the increasing number of nephropathia epidemica (NE) infections in humans, caused by Puumala virus carried by bank voles (Myodes glareolus), has triggered studies of environmental factors driving these infections. NE infections have been shown to occur in specific geographical areas characterized by environmental factors that influence the distribution and dynamics of host populations and virus persistence in the soil. Here, we review the influence of environmental conditions (including climate factors, food availability and habitat conditions) with respect to incidence in humans and seroprevalence in rodents, considering both direct and indirect transmission pathways. For each type of environmental factor, results and discrepancies between studies are presented and examined in the light of biological hypotheses. Overall, food availability and temperature appear to be the main drivers of host seroprevalence and NE incidence, but data quality and statistical approaches varied greatly among studies. We highlight the issues that now need to be addressed and suggest improvements for study design in regard to the current knowledge on hantavirus epidemiology. © 2016 Blackwell Verlag GmbH.

Survival-related Selection Bias in Studies of Racial Health Disparities: The Importance of the Target Population and Study Design.

PubMed

Howe, Chanelle J; Robinson, Whitney R

2018-07-01

The impact of survival-related selection bias has not always been discussed in relevant studies of racial health disparities. Moreover, the analytic approaches most frequently employed in the epidemiologic literature to minimize selection bias are difficult to implement appropriately in racial disparities research. This difficulty stems from the fact that frequently employed analytic techniques require that common causes of survival and the outcome are accurately measured. Unfortunately, such common causes are often unmeasured or poorly measured in racial health disparities studies. In the absence of accurate measures of the aforementioned common causes, redefining the target population or changing the study design represents a useful approach for reducing the extent of survival-related selection bias. To help researchers recognize and minimize survival-related selection bias in racial health disparities studies, we illustrate the aforementioned selection bias and how redefining the target population or changing the study design can be useful.

A practical guide to epidemiological practice and standards in the identification and validation of diagnostic markers using a bladder cancer example.

PubMed

Behrens, T; Bonberg, N; Casjens, S; Pesch, B; Brüning, T

2014-01-01

Technical advances to analyze biological markers have generated a plethora of promising new marker candidates for early detection of cancer. However, in subsequent analyses only few could be successfully validated as being predictive, clinically useful, or effective. This failure is partially due to rapid publication of results that were detected in early stages of biomarker research. Methodological considerations are a major concern when carrying out molecular epidemiological studies of diagnostic markers to avoid errors that increase the potential for bias. Although guidelines for conducting studies and reporting of results have been published to improve the quality of marker studies, their planning and execution still need to be improved. We will discuss different sources of bias in study design, handling of specimens, and statistical analysis to illustrate possible pitfalls associated with marker research, and present legal, ethical, and technical considerations associated with storage and handling of specimens. This article presents a guide to epidemiological standards in marker research using bladder cancer as an example. Because of the possibility to detect early cancer stages due to leakage of molecular markers from the target organ or exfoliation of tumor cells into the urine, bladder cancer is particularly useful to study diagnostic markers. To improve the overall quality of marker research, future developments should focus on networks of studies and tissue banks according to uniform legal, ethical, methodological, and technical standards. This article is part of a Special Issue entitled: Computational Proteomics in the Post-Identification Era. Guest Editors: Martin Eisenacher and Christian Stephan. © 2013.

Injury and illness epidemiology in soccer – effects of global geographical differences – a call for standardized and consistent research studies

PubMed Central

Gillogly, Scott; Singh, Gurcharan; Chamari, Karim

2017-01-01

Soccer is the most popular sport in the world. While injuries and illnesses can affect the players’ health and performance, they can also have a major economic impact on teams. Moreover, several studies have shown the favourable association between higher player availability and team success. Therefore, injury prevention could directly impact clubs’ financial balance and teams’ performance via increased player availability. To be able to develop effective methods of injury prevention, it is vital to first determine the scope and the degree of the problem: the mechanisms and types of injuries, their frequency and severity, etc. According to the most widely known prevention model, systematic injury surveillance is the first and most fundamental step towards injury prevention. Since epidemiological studies have shown that injuries and illnesses in soccer players differ from region to region, it is important to establish a specific injuries and illness database in order to guide specific preventive actions. Since Asia is the largest continent, with the highest number of soccer players, and in the light of the long-term research on injuries performed in UEFA clubs, the authors of the present article present the AFC surveillance. Some methodological issues related to this prospective design study are discussed. The definition of injury and illness and the methods to track players’ exposure are described along with the potential challenges related to such a vast scale study. This article is also a call for action to have consistent and standardized epidemiological studies on soccer injuries and illnesses, with the aim to improve their prevention. PMID:29158618

Integrating Phylodynamics and Epidemiology to Estimate Transmission Diversity in Viral Epidemics

PubMed Central

Magiorkinis, Gkikas; Sypsa, Vana; Magiorkinis, Emmanouil; Paraskevis, Dimitrios; Katsoulidou, Antigoni; Belshaw, Robert; Fraser, Christophe; Pybus, Oliver George; Hatzakis, Angelos

2013-01-01

The epidemiology of chronic viral infections, such as those caused by Hepatitis C Virus (HCV) and Human Immunodeficiency Virus (HIV), is affected by the risk group structure of the infected population. Risk groups are defined by each of their members having acquired infection through a specific behavior. However, risk group definitions say little about the transmission potential of each infected individual. Variation in the number of secondary infections is extremely difficult to estimate for HCV and HIV but crucial in the design of efficient control interventions. Here we describe a novel method that combines epidemiological and population genetic approaches to estimate the variation in transmissibility of rapidly-evolving viral epidemics. We evaluate this method using a nationwide HCV epidemic and for the first time co-estimate viral generation times and superspreading events from a combination of molecular and epidemiological data. We anticipate that this integrated approach will form the basis of powerful tools for describing the transmission dynamics of chronic viral diseases, and for evaluating control strategies directed against them. PMID:23382662

Essential problems in the interpretation of epidemiologic evidence for an association between mobile phone use and brain tumours

NASA Astrophysics Data System (ADS)

Kundi, Michael

2010-11-01

Due to the close proximity of a mobile phone to the head when placing a call, concerns have been raised that exposure from microwaves during mobile phone use may exert adverse health effects and, in particular, may increase the risk of brain tumours. In response to these concerns epidemiological studies have been conducted, most applying the case-control design. While epidemiology can provide decisive evidence for an association between an exposure and a disease fundamental problems arise if exposure is short compared to the natural history of the disease. For brain tumours latencies of decades have been implicated making special considerations about potential effects of exposures necessary that commence during an already growing tumour. It is shown that measures of disease risk like odds ratios and relative risks can under such circumstances not be interpreted as indicators of a long term effect on incidences in the exposed population. Besides this problem, the issues of a suitable exposure metric and the selection of endpoints are unresolved. It is shown that the solution of these problems affords knowledge about the mechanism of action by which exposure increases the risk of manifest disease.

[The clinico-epidemiological characteristics of cholera patients in Mexico City].

PubMed

Vilchis-Guizar, A E; Uribe-Márquez, S; Pérez-Sánchez, P L

1999-01-01

To compare the clinical and epidemiological characteristics of cholera patients and patients with diarrhea of different etiology (controls), treated at Mexican Institute of Social Security medical units in northeast Mexico City, from 1995 to 1998. Cross-sectional analytical study design. Data were collected using the official form "Immediate Notification of Cholera Cases" that each medical unit reports to the Coordination of Community Health. Statistical analysis consisted of comparisons of means and proportions between both groups. In 4,952 notifications, there were 588 cholera cases and 4,364 controls. The age range of cases was 39 to 51 years and 54% were females. During 1995 and 1997 (years with higher proportion of cases) patients with cholera had a greater frequency of watery evacuations than controls (97% vs. 73%), "rice water" appearance (31% vs. 13%), vomiting (72% vs. 63%), muscular spasms (49% vs. 26%), dehydration (83% vs. 71%), hypovolemic shock (10% vs. 1%) and death (0.85% vs. 0.25%). These differences were statistically significant. Cholera presents a biannual cyclic behavior; greater frequencies are associated with greater severity and complications. It is necessary to increase epidemiologic surveillance and medical efforts for opportune diagnosis and treatment.

Quantifying Transmission.

PubMed

Woolhouse, Mark

2017-07-01

Transmissibility is the defining characteristic of infectious diseases. Quantifying transmission matters for understanding infectious disease epidemiology and designing evidence-based disease control programs. Tracing individual transmission events can be achieved by epidemiological investigation coupled with pathogen typing or genome sequencing. Individual infectiousness can be estimated by measuring pathogen loads, but few studies have directly estimated the ability of infected hosts to transmit to uninfected hosts. Individuals' opportunities to transmit infection are dependent on behavioral and other risk factors relevant given the transmission route of the pathogen concerned. Transmission at the population level can be quantified through knowledge of risk factors in the population or phylogeographic analysis of pathogen sequence data. Mathematical model-based approaches require estimation of the per capita transmission rate and basic reproduction number, obtained by fitting models to case data and/or analysis of pathogen sequence data. Heterogeneities in infectiousness, contact behavior, and susceptibility can have substantial effects on the epidemiology of an infectious disease, so estimates of only mean values may be insufficient. For some pathogens, super-shedders (infected individuals who are highly infectious) and super-spreaders (individuals with more opportunities to transmit infection) may be important. Future work on quantifying transmission should involve integrated analyses of multiple data sources.

Epidemiology of soy and cancer: perspectives and directions.

PubMed

Persky, V; Van Horn, L

1995-03-01

Previous epidemiologic studies of the effects of soy protein on cancer risk have been limited by small variations in soy intake, inability to separate soy from other dietary variables and difficulties inherent in relating dietary intake to the development of cancer several decades later. As a result, although existing data suggest that soy protein may be protective for cancer risk, results are overall inconclusive. There is also evidence that soy products may affect risk factors for cancer, such as endogenous hormone levels. Preliminary data from our group indicate that young Adventist women who are vegetarians with high soy intake and a lower risk of breast cancer may have higher levels of an adrenal androgen, dehydroepiandrosterone sulfate. Other groups have noted that soy protein may be associated with alterations in the regulation and binding of ovarian hormones. Additional studies examining effects of soy protein on risk factors for cancer would help, not only in delineating mechanisms of cancer development, but also in designing dietary programs aimed at cancer prevention.

Advances in studies of disease-navigating webs: Sarcoptes scabiei as a case study

PubMed Central

2014-01-01

The discipline of epidemiology is the study of the patterns, causes and effects of health and disease conditions in defined anima populations. It is the key to evidence-based medicine, which is one of the cornerstones of public health. One of the important facets of epidemiology is disease-navigating webs (disease-NW) through which zoonotic and multi-host parasites in general move from one host to another. Epidemiology in this context includes (i) classical epidemiological approaches based on the statistical analysis of disease prevalence and distribution and, more recently, (ii) genetic approaches with approximations of disease-agent population genetics. Both approaches, classical epidemiology and population genetics, are useful for studying disease-NW. However, both have strengths and weaknesses when applied separately, which, unfortunately, is too often current practice. In this paper, we use Sarcoptes scabiei mite epidemiology as a case study to show how important an integrated approach can be in understanding disease-NW and subsequent disease control. PMID:24406101

Epidemiology of Overuse and Acute Injuries Among Competitive Collegiate Athletes

PubMed Central

Yang, Jingzhen; Tibbetts, Abigail S.; Covassin, Tracey; Cheng, Gang; Nayar, Saloni; Heiden, Erin

2012-01-01

Context: Although overuse injuries are gaining attention, epidemiologic studies on overuse injuries in male and female collegiate athletes are lacking. (70.7%) acute injuries were reported. The overall injury rate was Objective: To report the epidemiology of overuse injuries sustained by collegiate athletes and to compare the rates of overuse and acute injuries. Design: Descriptive epidemiology study. Setting: A National Collegiate Athletic Association Division I university. Patients or Other Participants: A total of 1317 reported injuries sustained by 573 male and female athletes in 16 collegiate sports teams during the 2005–2008 seasons. Main Outcome Measure(s): The injury and athlete-exposure (AE) data were obtained from the Sports Injury Monitoring System. An injury was coded as either overuse or acute based on the nature of injury. Injury rate was calculated as the total number of overuse (or acute) injuries during the study period divided by the total number of AEs during the same period. Results: A total of 386 (29.3%) overuse injuries and 931 63.1 per 10000 AEs. The rate ratio (RR) of acute versus overuse injuries was 2.34 (95% confidence interval [CI] = 2.05, 2.67). Football had the highest RR (RR = 8.35, 95% CI = 5.38, 12.97), and women's rowing had the lowest (RR = 0.75, 95% CI = 0.51, 1.10). Men had a higher acute injury rate than women (49.8 versus 38.6 per 10000 AEs). Female athletes had a higher rate of overuse injury than male athletes (24.6 versus 13.2 per 10000 AEs). More than half of the overuse injuries (50.8%) resulted in no time loss from sport. Conclusions: Additional studies are needed to examine why female athletes are at greater risk for overuse injuries and identify the best practices for prevention and rehabilitation of overuse injuries. PMID:22488286

Psychiatric epidemiology in India.

PubMed

Math, Suresh Bada; Chandrashekar, C R; Bhugra, Dinesh

2007-09-01

Epidemiological studies report prevalence rates for psychiatric disorders from 9.5 to 370/1000 populations in India. This review critically evaluates the prevalence rate of mental disorders as reported in Indian epidemiological studies. Extensive search of PubMed, NeuroMed and MEDLARS using search terms "psychiatry" and "epidemiology" was done. Manual search of literature was also done. Retrieved articles were systematically selected using inclusion and exclusion criteria. Only sixteen prevalence studies fulfilled the study criteria. Most of the epidemiological studies done in India neglected anxiety disorders, substance dependence disorders, co-morbidity and dual diagnosis. The use of poor sensitive screening instruments, single informant and systematic underreporting has added to the discrepancy in the prevalence rate. The prevalence of mental disorders reported in epidemiological surveys can be considered lower estimates rather than accurate reflections of the true prevalence in the population. Researchers have focused on broad non-specific, non-modifiable risk factors, such as age, gender and social class. Future research focused on the general population, longitudinal (prospective), multi-centre, co-morbid studies, assessment of disability, functioning, family burden and quality of life studies involving a clinical service providing approach, is required.

Epidemiological profile of colombian patients with rheumatoid arthritis in a specialized care clinic.

PubMed

Bautista-Molano, Wilson; Fernández-Avila, Daniel; Jiménez, Ruth; Cardozo, Rosa; Marín, Andrés; Soler, María Del Pilar; Gómez, Olga; Ruiz, Oscar

Few studies report the epidemiological profile of RA patients attending clinics for comprehensive care. We describe the clinical, socio-demographic characteristics and comorbidities of a cohort of patients with RA. Cross-sectional study in a cohort of patients according to ACR criteria/EULAR 2010 classification who have entered to the AR clinic since October 2012 until May 2014, referred from primary care. Frequencies for socio-demographic, comorbidity, state of disease activity, functional status, biomarkers and therapeutic modalities variables are described. In total, 1652 patients were included with a mean age of 58 years and a duration of 9 years. Rheumatoid factor was positive in 80% and anti-citrullinated peptide antibody in 63% of patients. In total, 43.6% of patients had comorbidities: Hypertension (20.4%), osteoporosis (17.3%) and Sjögren's syndrome (10.4%). Fifty percent of the patients had moderate and high disease activity level measured by DAS-28 score, and the mean HAQ score was 0.64 (DS 1.12). Seventy three percent of patients were treated with oral disease modified anti rheumatic treatment and 63.6% of them were with methotrexate. 42.4% of the patients were treated with glucocorticoids (mean dose 6.3mg). The epidemiological behavior of a group of RA patients is reported. The presence of comorbidities is significant affecting the risk of morbidity and mortality in these patients. The definition of the epidemiological profile of this population will allow the design of research questions to resolve outstanding problems in the clinical context of this pathology. Copyright © 2015 Elsevier España, S.L.U. and Sociedad Española de Reumatología y Colegio Mexicano de Reumatología. All rights reserved.

Regression Discontinuity for Causal Effect Estimation in Epidemiology.

PubMed

Oldenburg, Catherine E; Moscoe, Ellen; Bärnighausen, Till

Regression discontinuity analyses can generate estimates of the causal effects of an exposure when a continuously measured variable is used to assign the exposure to individuals based on a threshold rule. Individuals just above the threshold are expected to be similar in their distribution of measured and unmeasured baseline covariates to individuals just below the threshold, resulting in exchangeability. At the threshold exchangeability is guaranteed if there is random variation in the continuous assignment variable, e.g., due to random measurement error. Under exchangeability, causal effects can be identified at the threshold. The regression discontinuity intention-to-treat (RD-ITT) effect on an outcome can be estimated as the difference in the outcome between individuals just above (or below) versus just below (or above) the threshold. This effect is analogous to the ITT effect in a randomized controlled trial. Instrumental variable methods can be used to estimate the effect of exposure itself utilizing the threshold as the instrument. We review the recent epidemiologic literature reporting regression discontinuity studies and find that while regression discontinuity designs are beginning to be utilized in a variety of applications in epidemiology, they are still relatively rare, and analytic and reporting practices vary. Regression discontinuity has the potential to greatly contribute to the evidence base in epidemiology, in particular on the real-life and long-term effects and side-effects of medical treatments that are provided based on threshold rules - such as treatments for low birth weight, hypertension or diabetes.

Lessons learnt from a three-year pilot field epidemiology training programme.

PubMed

Hoy, Damian; Durand, A Mark; Hancock, Thane; Cash, Haley L; Hardie, Kate; Paterson, Beverley; Paulino, Yvette; White, Paul; Merritt, Tony; Fitzgibbons, Dawn; Gopalani, Sameer Vali; Flint, James; Edwin A Merilles, Onofre; Kashiwabara, Mina; Biaukula, Viema; Lepers, Christelle; Souares, Yvan; Nilles, Eric; Batikawai, Anaseini; Huseynova, Sevil; Patel, Mahomed; Saketa, Salanieta T; Durrheim, David; Henderson, Alden; Roth, Adam

2017-01-01

The Pacific region has widely dispersed populations, limited financial and human resources and a high burden of disease. There is an urgent need to improve the availability, reliability and timeliness of useable health data. The purpose of this paper is to share lessons learnt from a three-year pilot field epidemiology training programme that was designed to respond to these Pacific health challenges. The pilot programme built on and further developed an existing field epidemiology training programme for Pacific health staff. The programme was delivered in country by epidemiologists working for Pacific Public Health Surveillance Network partners. The programme consisted of five courses: four one-week classroom-based courses and one field epidemiology project. Sessions were structured so that theoretical understanding was achieved through interaction and reinforced through practical hands-on group activities, case studies and other interactive practical learning methods. As of September 2016, 258 students had commenced the programme. Twenty-six course workshops were delivered and one cohort of students had completed the full five-course programme. The programme proved popular and gained a high level of student engagement. Face-to-face delivery, a low student-to-facilitator ratio, substantial group work and practical exercises were identified as key factors that contributed to the students developing skills and confidence. Close engagement of leaders and the need to quickly evaluate and adapt the curriculum were important lessons, and the collaboration between external partners was considered important for promoting a harmonized approach to health needs in the Pacific.

Exposure to non-persistent pesticides and thyroid function: A systematic review of epidemiological evidence.

PubMed

Campos, Élida; Freire, Carmen

2016-08-01

Numerous pesticides are recognized for their endocrine-disrupting properties. Non-persistent pesticides such as organophosphates, dithiocarbamates and pyrethroids may interfere with thyroid function as suggested by animal studies. However, the influence of chronic exposure to these compounds on thyroidal functions in humans remains to be determined. The present study aimed to review epidemiological evidence for an association between exposure to non-persistent pesticides and circulating levels of thyroid hormones (thyroxin [T4] and triiodothyronine [T3]) and thyroid-stimulating hormone (TSH). A systematic review was conducted using MEDLINE, SCOPUS and Virtual Health Library (BVS) databases. Articles were limited to original studies and reports published in English, Portuguese or Spanish. Nineteen epidemiological studies were identified, 17 of which were cross-sectional, 14 were of occupationally exposed workers and 11 used exposure biomarkers. Fungicides and organophosphates (OP) insecticides were the most studied pesticides. Although methodological heterogeneity between studies was noted, particularly regarding study design, exposure assessment, and control of confounding, most of them showed associations with changes in T3 and T4, and/or TSH levels, while results from a few of these are consistent with experimental data supporting the findings that non-persistent pesticide exposure exerts hypothyroid-like effects. However, reporting quality was moderate to poor in 50% of the studies, particularly regarding method of selection of participants and discussion of external validity. Overall, current knowledge regarding the impact of non-persistent pesticides on human thyroid function is still limited. Given the widespread use of pesticides, future research should assess effects of exposure to currently-used pesticides in cohort studies combining comprehensive questionnaire-based assessment and biomarkers. Investigators need to pay particular attention to exposure during critical windows of brain development and exposure in agricultural populations. Copyright © 2016 Elsevier GmbH. All rights reserved.

Developing the WCRF International/University of Bristol Methodology for Identifying and Carrying Out Systematic Reviews of Mechanisms of Exposure-Cancer Associations.

PubMed

Lewis, Sarah J; Gardner, Mike; Higgins, Julian; Holly, Jeff M P; Gaunt, Tom R; Perks, Claire M; Turner, Suzanne D; Rinaldi, Sabina; Thomas, Steve; Harrison, Sean; Lennon, Rosie J; Tan, Vanessa; Borwick, Cath; Emmett, Pauline; Jeffreys, Mona; Northstone, Kate; Mitrou, Giota; Wiseman, Martin; Thompson, Rachel; Martin, Richard M

2017-11-01

Background: Human, animal, and cell experimental studies; human biomarker studies; and genetic studies complement epidemiologic findings and can offer insights into biological plausibility and pathways between exposure and disease, but methods for synthesizing such studies are lacking. We, therefore, developed a methodology for identifying mechanisms and carrying out systematic reviews of mechanistic studies that underpin exposure-cancer associations. Methods: A multidisciplinary team with expertise in informatics, statistics, epidemiology, systematic reviews, cancer biology, and nutrition was assembled. Five 1-day workshops were held to brainstorm ideas; in the intervening periods we carried out searches and applied our methods to a case study to test our ideas. Results: We have developed a two-stage framework, the first stage of which is designed to identify mechanisms underpinning a specific exposure-disease relationship; the second stage is a targeted systematic review of studies on a specific mechanism. As part of the methodology, we also developed an online tool for text mining for mechanism prioritization (TeMMPo) and a new graph for displaying related but heterogeneous data from epidemiologic studies (the Albatross plot). Conclusions: We have developed novel tools for identifying mechanisms and carrying out systematic reviews of mechanistic studies of exposure-disease relationships. In doing so, we have outlined how we have overcome the challenges that we faced and provided researchers with practical guides for conducting mechanistic systematic reviews. Impact: The aforementioned methodology and tools will allow potential mechanisms to be identified and the strength of the evidence underlying a particular mechanism to be assessed. Cancer Epidemiol Biomarkers Prev; 26(11); 1667-75. ©2017 AACR . ©2017 American Association for Cancer Research.

Can the frequency and risks of fatal adverse drug events be determined?

PubMed

Kelly, W N

2001-05-01

Death is the ultimate adverse drug event. Despite its importance, the frequency of fatal adverse drug events is unknown. Estimates in the United States are as high as 140,000/year, although this number is heavily disputed. Potential reasons and risks for fatal adverse drug events, as well as epidemiologic designs for studying this important public health issue, are discussed and issues are raised to promote further thought.

Expansion of the E138A mutation in newly diagnosed HIV-infected patients in Gran Canaria.

PubMed

Chamizo, Francisco; Gilarranz, Raúl; Tosco, Tomás; Carrillo, Deyanira; Holguín, África; Santana, Évora; Pérez-Arellano, Jose Luís; Hernández, Michele; Francés, Adela; Cárdenes, Miguel Ángel; Zarzalejos, Jose María; Pena-López, María José

2016-09-01

Molecular epidemiology allows us to know local HIV transmission and to design strategies of prevention. We studied 25 HIV newly diagnosed patients with the E138A mutation since the year 2010. Most transmission networks involved young and promiscuous men who have sex with men. Recent infection was only documented in patients grouped into the smaller clusters. Copyright © 2016 Elsevier Inc. All rights reserved.

Environmental exposures and pediatric kidney function and disease: A systematic review.

PubMed

Zheng, Laura Y; Sanders, Alison P; Saland, Jeffrey M; Wright, Robert O; Arora, Manish

2017-10-01

Environmental chemical exposures have been implicated in pediatric kidney disease. No appraisal of the available evidence has been conducted on this topic. We performed a systematic review of the epidemiologic studies that assessed association of environmental exposures with measures of kidney function and disease in pediatric populations. The search period went through July 2016. We found 50 studies that met the search criteria and were included in this systematic review. Environmental exposures reviewed herein included lead, cadmium, mercury, arsenic, fluoride, aflatoxin, melamine, environmental tobacco, bisphenol A, dental procedures, phthalates, ferfluorooctanoic acid, triclosan, and thallium/uranium. Most studies assessed environmental chemical exposure via biomarkers but four studies assessed exposure via proximity to emission source. There was mixed evidence of association between metal exposures, and other non-metal environmental exposures and pediatric kidney disease and other kidney disease biomarkers. The evaluation of causality is hampered by the small numbers of studies for each type of environmental exposure, as well as lack of study quality and limited prospective evidence. There is a need for well-designed epidemiologic studies of environmental chemical exposures and kidney disease outcomes. Copyright © 2017. Published by Elsevier Inc.

Molecular and epidemiological characterization of canine Pseudomonas otitis using a prospective case-control study design.

PubMed

Morris, Daniel O; Davis, Meghan F; Palmeiro, Brian S; O'Shea, Kathleen; Rankin, Shelley C

2017-02-01

Pseudomonas aeruginosa is an opportunistic pathogen of the canine ear canal and occupies aquatic habitats in the environment. Nosocomial and zoonotic transmission of P. aeruginosa have been documented, including clonal outbreaks. The primary objective of this study was to assess various environmental exposures as potential risk factors for canine Pseudomonas otitis. It was hypothesized that isolates derived from infected ears would be clonal to isolates derived from household water sources and the mouths of human and animal companions of the study subjects. Seventy seven privately owned dogs with otitis were enrolled, along with their human and animal household companions, in a case-control design. Data on potential risk factors for Pseudomonas otitis were collected. Oral cavities of all study subjects, their human and animal companions, and household water sources were sampled. Pulsed field gel electrophoresis was used to estimate clonal relatedness of P. aeruginosa isolates. In a multivariate model, visiting a dog park was associated with 77% increased odds of case status (P = 0.048). Strains clonal to the infection isolates were obtained from subjects' mouths (n = 18), companion pets' mouths (n = 5), pet owners' mouths (n = 2), water bowls (n = 7) and water taps (n = 2). Clonally related P. aeruginosa isolates were obtained from dogs that had no clear epidemiological link. Genetic homology between otic and environmental isolates is consistent with a waterborne source for some dogs, and cross-contamination with other human and animal members within some households. © 2016 ESVD and ACVD.

Maternal Influenza Immunization and Adverse Birth Outcomes: Using Data and Practice to Inform Theory and Research Design.

PubMed

Phadke, Varun K; Steinhoff, Mark C; Omer, Saad B; MacDonald, Noni E

2016-12-01

Maternal influenza immunization can reduce influenza-attributable morbidity and mortality among pregnant women and infants who are too young to be vaccinated. Data from empirical studies also support the hypothesis that immunization can protect the fetus against adverse outcomes if the mother is exposed to influenza. In their theoretical analysis in the Journal, Hutcheon et al. (Am J Epidemiol 2016;184(3):227-232) critiqued the existing evidence of the fetal benefits of maternal influenza immunization by calculating the sample sizes needed to demonstrate hypothetical reductions in risk and concluded that the benefits observed in empirical studies are likely implausible. However, in their analysis, they did not take into account multiple fundamental characteristics of influenza epidemiology, including the time-variable effects of influenza illness and vaccination during pregnancy, or well-known differences in disease epidemiology between seasons, populations, and geographic regions. Although these and other factors might affect the magnitude of fetal benefit conferred by maternal influenza immunization, studies in which investigators have accounted for influenza circulation have demonstrated a consistent protective effect against a variety of adverse birth outcomes; those studies include the only randomized controlled trial designed a priori and adequately powered to do so. Only a comprehensive and nuanced assessment of the evidence base will allow for effective translation of these data into a global immunization policy. © The Author 2016. Published by Oxford University Press on behalf of the Johns Hopkins Bloomberg School of Public Health.

Injuries in Competitive Dragon Boating

PubMed Central

Mukherjee, Swarup; Leong, Hin Fong; Chen, Simin; Foo, Yong Xiang Wayne; Pek, Hong Kiat

2014-01-01

Background: Dragon boating is a fast-growing team water sport and involves forceful repetitive motions that predispose athletes to overuse injuries. Despite the rising popularity of the sport, there is a lack of studies on injury epidemiology in dragon boating. Purpose: To investigate the injury epidemiology in competitive dragon boating athletes. Study Design: Descriptive epidemiological study. Methods: A total of 95 dragon boaters (49 males, 46 females) representing their respective universities took part in this study. Data were collected retrospectively using a reliable and valid self-report questionnaire. The study period was from August 2012 to July 2013. Results: A total of 104 musculoskeletal injuries were reported (3.82 injuries/1000 athlete-exposures), 99% of which occurred during training. The most commonly injured regions were the lower back (22.1%), shoulder (21.1%), and wrist (17.3%). The majority of injuries were due to overuse (56.3%), and incomplete muscle-tendon strain was the most prevalent type of injury (50.5%). The time loss from injuries varied. In addition, a significant majority of the dragon boating athletes incurred nonmusculoskeletal injuries, with abrasions (90.5%), blisters (78.9%), and sunburns (72.6%) being the most common. Conclusion: Competitive dragon boating has a moderately high injury incidence, and there seems to be a direct relationship between exposure time and injury rate. A majority of the injuries are overuse in nature, and the body parts most actively involved in paddling movement are at higher risk of injuries. The high incidence of nonmusculoskeletal injuries in dragon boaters suggested that these injuries are likely outcomes of participation in the sport. PMID:26535280

The 2016 HIGh Heels: Health effects And psychosexual BenefITS (HIGH HABITS) study: systematic review of reviews and additional primary studies.

PubMed

Barnish, Max; Morgan, Heather May; Barnish, Jean

2017-08-01

High-heeled shoes (high heels) are frequently worn by many women and form an important part of female gender identity. Issues of explicit and implicit compulsion to wear high heels have been noted. Previous studies and reviews have provided evidence that high heels are detrimental to health. However, the evidence base remains fragmented and no review has covered both the epidemiological and biomechanical literature. In addition, no review has considered the psychosexual benefits that offer essential context in understanding the public health challenge of high heels. We searched seven major bibliographic databases up to November 2016, in addition to supplementary searches. We initially identified all review articles of any design that assessed either the psychosexual benefits or negative musculoskeletal health effects of high heels, the latter looking at both the epidemiological and biomechanical perspectives. We additionally considered additional primary studies on areas that had not been reviewed before or in which a marked lack of evidence had been noted. Data were extracted onto standardised forms. Proportionate second review was conducted. A total of 506 unique records were identified, 27 full-text publications were screened and 20 publications (7 reviews and 13 additional studies) were included in our evidence synthesis. The most up-to-date epidemiological review provides clear evidence of an association between high heel wear and hallux valgus, musculoskeletal pain and first-party injury. The body of biomechanical reviews provides clear evidence of changes indicative of increased risk of these outcomes, as well as osteoarthritis, which is not yet evidenced by epidemiological studies. There were no reviews on psychosexual benefits, but all five identified original studies provided evidence of increased attractiveness and/or an impact on men's behaviour associated with high heel wear. With regard to second-party injury, evidence is limited to one descriptive study and eight case reports. Our evidence synthesis clearly shows that high heels bring psychosexual benefits to women but are detrimental to their health. In light of this dilemma, it is important that women's freedom of choice is respected and that any remaining issues of explicit or implicit compulsion are addressed.

Does Cannabis Onset Trigger Cocaine Onset? A Case-Crossover Approach

PubMed Central

O’Brien, Megan S.; Comment, Leah Andrews; Liang, Kung Yee; Anthony, James C.

2016-01-01

Psychiatric researchers tend to select the discordant co-twin design when they seek to hold constant genetic influence while estimating exposure-associated disease risk. The epidemiologic case-crossover research design developed for the past two decades represents a viable alternative, not often seen in psychiatric studies. Here, we turn to the epidemiologic case-crossover approach to examine the idea that cannabis onset is a proximal trigger for cocaine use, with the power of ‘subject-as-own-control’ research used to hold constant antecedent characteristics of the individual drug user, including genetic influence and other traits experienced up to the time of the observed hazard and control intervals. Data are from newly incident cocaine users identified in the 2002–2006 U.S. National Surveys on Drug Use and Health. Among these cocaine users, 48 had both cannabis onset and cocaine onset in the same month-long hazard interval; the expected value is 30 users, based on the control interval we had pre-specified for case-crossover estimation (estimated relative risk, RR = 1.6; exact mid-p = 0.042). Within the framework of a subject-as-own-control design, the evidence is consistent with the hypothesis that cannabis onset is a proximal trigger for cocaine use, with genetic influences (and many environmental conditions and processes) held constant. Limitations are noted and implications discussed. PMID:22228642

Combining epidemiology and biomechanics in sports injury prevention research: a new approach for selecting suitable controls.

PubMed

Finch, Caroline F; Ullah, Shahid; McIntosh, Andrew S

2011-01-01

Several important methodological issues need to be considered when designing sports injury case-control studies. Major design goals for case-control studies include the accounting for prior injury risk exposure, and optimal definitions of both cases and suitable controls are needed to ensure this. This article reviews methodological aspects of published sports injury case-control studies, particularly with regard to the selection of controls. It argues for a new approach towards selecting controls for case-control studies that draws on an interface between epidemiological and biomechanical concepts. A review was conducted to identify sport injury case-control studies published in the peer-review literature during 1985-2008. Overall, 32 articles were identified, of which the majority related to upper or lower extremity injuries. Matching considerations were used for control selection in 16 studies. Specific mention of application of biomechanical principles in the selection of appropriate controls was absent from all studies, including those purporting to evaluate the benefits of personal protective equipment to protect against impact injury. This is a problem because it could lead to biased conclusions, as cases and controls are not fully comparable in terms of similar biomechanical impact profiles relating to the injury incident, such as site of the impact on the body. The strength of the conclusions drawn from case-control studies, and the extent to which results can be generalized, is directly influenced by the definition and recruitment of cases and appropriate controls. Future studies should consider the interface between epidemiological and biomechanical concepts when choosing appropriate controls to ensure that proper adjustment of prior exposure to injury risk is made. To provide necessary guidance for the optimal selection of controls in case-control studies of interventions to prevent sports-related impact injury, this review outlines a new case-control selection strategy that reflects the importance of biomechanical considerations, which ensures that controls are selected based on the presence of the same global injury mechanism as the cases. To summarize, the general biomechanical principles that should apply to the selection of controls in future case-control studies are as follows: (i) each control must have been exposed to the same global injury mechanism as the case, (e.g. head impact, fall onto outstretched arm); and (ii) intrinsic (individual) factors (e.g. age, sex, skill level) that might modify the person's response to the relevant biomechanical loads are adjusted when either selecting the controls or are in the analysis phase. The same considerations for control selection apply to other study designs such as matched cohort studies or case-crossover studies.

TIME-INTEGRATED EXPOSURE MEASURES TO IMPROVE THE PREDICTIVE POWER OF EXPOSURE CLASSIFICATION FOR EPIDEMIOLOGIC STUDIES

EPA Science Inventory

Accurate exposure classification tools are required to link exposure with health effects in epidemiological studies. Although long-term integrated exposure measurements are a critical component of exposure assessment, the ability to include these measurements into epidemiologic...

Epidemiological evidence in forensic pharmacovigilance.

PubMed

Persaud, Nav; Healy, David

2012-01-01

Until recently epidemiological evidence was not regarded as helpful in determining cause and effect. It generated associations that then had to be explained in terms of bio-mechanisms and applied to individual patients. A series of legal cases surrounding possible birth defects triggered by doxylamine (Bendectin) and connective tissue disorders linked to breast implants made it clear that in some instances epidemiological evidence might have a more important role, but the pendulum swung too far so that epidemiological evidence has in recent decades been given an unwarranted primacy, partly perhaps because it suits the interests of certain stakeholders. Older and more recent epidemiological studies on doxylamine and other antihistamines are reviewed to bring out the ambiguities and pitfalls of an undue reliance on epidemiological studies.

Research design and statistical methods in Pakistan Journal of Medical Sciences (PJMS).

PubMed

Akhtar, Sohail; Shah, Syed Wadood Ali; Rafiq, M; Khan, Ajmal

2016-01-01

This article compares the study design and statistical methods used in 2005, 2010 and 2015 of Pakistan Journal of Medical Sciences (PJMS). Only original articles of PJMS were considered for the analysis. The articles were carefully reviewed for statistical methods and designs, and then recorded accordingly. The frequency of each statistical method and research design was estimated and compared with previous years. A total of 429 articles were evaluated (n=74 in 2005, n=179 in 2010, n=176 in 2015) in which 171 (40%) were cross-sectional and 116 (27%) were prospective study designs. A verity of statistical methods were found in the analysis. The most frequent methods include: descriptive statistics (n=315, 73.4%), chi-square/Fisher's exact tests (n=205, 47.8%) and student t-test (n=186, 43.4%). There was a significant increase in the use of statistical methods over time period: t-test, chi-square/Fisher's exact test, logistic regression, epidemiological statistics, and non-parametric tests. This study shows that a diverse variety of statistical methods have been used in the research articles of PJMS and frequency improved from 2005 to 2015. However, descriptive statistics was the most frequent method of statistical analysis in the published articles while cross-sectional study design was common study design.

Alternative approaches to analytical designs in occupational injury epidemiology.

PubMed

Mittleman, M A; Maldonado, G; Gerberich, S G; Smith, G S; Sorock, G S

1997-08-01

In this paper, we discuss the theoretical framework upon which observational studies of occupational injuries are based. Following a general description of how causal effects are estimated, the challenges faced by researchers working in this area are outlined, with an emphasis on case-control studies. These challenges include defining the at-risk period for workers whose tasks change over time and whose hazard period may be very brief, evaluating the underreporting of both exposures and injuries, and considering the effects of multiple injuries per individual on study design and data analysis. We review both the theoretical and practical considerations in the design and conduct of traditional case-control studies, based on the collection of individual level data, as well as other approaches, such as using information culled from administrative and descriptive databases, and case-control studies in which the plant or work site is the unit of analysis. The case-crossover design is also reviewed and its utility for reducing confounding due to differences between individuals by self-matching is highlighted. While this design has not yet been applied to the work setting, its potential for increasing our understanding of the causes of acute-onset occupational injuries seems promising. Finally, a variety of hybrid designs are discussed, including combinations of case-control, case-crossover, and cohort designs.

ESTIMATING RESIDENTIAL EXPOSURE TO DRINKING WATER ARSENIC IN INNER MONGOLIA, CHINA FOR EPIDEMIOLOGIC STUDIES

EPA Science Inventory

ESTIMATING RESIDENTIAL EXPOSURE TO DRINKING WATER ARSENIC IN INNER MONGOLIA, CHINA FOR EPIDEMIOLOGIC STUDIES

Richard Kwok1, Pauline Mendola1 Zhixiong Ning2, Zhiyi Liu2 and Judy Mumford1

1) Epidemiology and Biomarkers Branch, Human Studies Division, NHEERL, US EPA, R...

Quasi-experimental study designs series-paper 10: synthesizing evidence for effects collected from quasi-experimental studies presents surmountable challenges.

PubMed

Becker, Betsy Jane; Aloe, Ariel M; Duvendack, Maren; Stanley, T D; Valentine, Jeffrey C; Fretheim, Atle; Tugwell, Peter

2017-09-01

To outline issues of importance to analytic approaches to the synthesis of quasi-experiments (QEs) and to provide a statistical model for use in analysis. We drew on studies of statistics, epidemiology, and social-science methodology to outline methods for synthesis of QE studies. The design and conduct of QEs, effect sizes from QEs, and moderator variables for the analysis of those effect sizes were discussed. Biases, confounding, design complexities, and comparisons across designs offer serious challenges to syntheses of QEs. Key components of meta-analyses of QEs were identified, including the aspects of QE study design to be coded and analyzed. Of utmost importance are the design and statistical controls implemented in the QEs. Such controls and any potential sources of bias and confounding must be modeled in analyses, along with aspects of the interventions and populations studied. Because of such controls, effect sizes from QEs are more complex than those from randomized experiments. A statistical meta-regression model that incorporates important features of the QEs under review was presented. Meta-analyses of QEs provide particular challenges, but thorough coding of intervention characteristics and study methods, along with careful analysis, should allow for sound inferences. Copyright © 2017 Elsevier Inc. All rights reserved.

The potential impact of epidemiology on the prevention of occupational disease

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wegman, D.H.

1992-07-01

This presentation reviews occupational epidemiology as a foundation for workplace disease prevention activities. By examining descriptive, etiologic and intervention occupational epidemiology studies, a range of opportunities are illustrated where epidemiology has played, or could play a principal role in guiding preventive efforts. Descriptive studies presented include ones based on vital records, on epidemic investigations, cross-sectional surveys, and surveillance. Etiologic studies review the largely successful development of knowledge for lung cancer and asbestos exposure for pulmonary effects of isocyanate exposures. However, attention is also directed to the need for etiologic studies of work environment risks for both cardiovascular and musculoskeletal disease.more » Finally importance is placed on the too infrequent epidemiologic studies of intervention. Historical examples of control of large risks from nickel cancers and silicosis are balanced with more recent examples of successes at reducing smaller risks of cardiovascular disease and oil acne. Throughout, emphasis is placed on the importance of reintegrating the academic discipline of epidemiology into the application of study findings to prevention of workplace risks.67 references.« less

Epidemiologic studies of electric and magnetic fields and cancer: Strategies for extending knowledge

DOE Office of Scientific and Technical Information (OSTI.GOV)

Savitz, D.A.

1993-12-01

Epidemiologic research concerning electric and magnetic fields in relation to cancer has focused on the potential etiologic roles of residential exposure on childhood cancer and occupational exposure on adult leukemia and brain cancer. Future residential studies must concentrate on exposure assessment that is enhanced by developing models of historical exposure, assessment of the relation between magnetic fields and wire codes, and consideration of alternate exposure indices. Study design issues deserving attention include possible biases in random digit dialing control selection, consideration of the temporal course of exposure and disease, and acquisition of the necessary information to assess the potential valuemore » of ecologic studies. Highest priorities are comprehensive evaluation of exposure patterns and sources and examination of the sociology and geography of residential wire codes. Future occupational studies should also concentrate on improved exposure assessment with increased attention to nonutility worker populations and development of historical exposure indicators that are superior to job titles alone. Potential carcinogens in the workplace that could act as confounders need to be more carefully examined. The temporal relation between exposure and disease and possible effect modification by other workplace agents should be incorporated into future studies. The most pressing need is for measurement of exposure patterns in a variety of worker populations and performance of traditional epidemiologic evaluations of cancer occurrence. The principal source of bias toward the null is nondifferential misclassification of exposure with improvements expected to enhance any true etiologic association that is present. Biases away from the null might include biased control selection in residential studies and chemical carcinogens acting as confounders in occupational studies. 51 refs., 1 tab.« less

Defining Chronic Cough: A Systematic Review of the Epidemiological Literature

PubMed Central

Song, Woo-Jung; Chang, Yoon-Seok; Faruqi, Shoaib; Kang, Min-Koo; Kim, Ju-Young; Kang, Min-Gyu; Kim, Sujeong; Jo, Eun-Jung; Lee, Seung-Eun; Kim, Min-Hye; Plevkova, Jana; Park, Heung-Woo

2016-01-01

Purpose Recent evidence suggests a global burden of chronic cough in general populations. However, the definitions vary greatly among epidemiological studies, and none have been validated for clinical relevance. We aimed to examine previous epidemiological definitions in detail and explore the operational characteristics. Methods A systematic review was conducted for epidemiological surveys that reported the prevalence of chronic cough in general adult populations during the years 1980 to 2013. A literature search was performed on Pubmed and Embase without language restriction. Epidemiological definitions for chronic cough were classified according to their components, such as cutoff duration. Meta-analyses were performed for the male-to-female ratio of chronic cough prevalence to explore operational characteristics of epidemiological definitions. Results A total of 70 studies were included in the systematic review. The most common epidemiological definition was identified as 'cough ≥3 months' duration without specification of phlegm (n=50); however, it conflicted with the cutoff duration in current clinical guidelines (cough ≥8 weeks). Meta-analyses were performed for the male-to-female ratio of chronic cough among 28 studies that reported sex-specific prevalence using the most common definition. The pooled male-to-female odds ratio was 1.26 (95% confidence interval 0.92-1.73) with significant heterogeneity (I2=96%, P<0.001), which was in contrast to clinical observations of female predominance from specialist clinics. Subgroup analyses did not reverse the ratio or reduce the heterogeneity. Conclusions This study identified major issues in defining chronic cough in future epidemiological studies. The conflict between epidemiological and clinical diagnostic criteria needs to be resolved. The unexpected difference in the gender predominance between the community and clinics warrants further studies. Clinical validation of the existing definition is required. PMID:26739408

Newspaper Coverage of Intimate Partner Violence: Skewing Representations of Risk.

PubMed

Carlyle, Kellie E; Slater, Michael D; Chakroff, Jennifer L

2008-03-01

How media portray intimate partner violence (IPV) has implications for public perceptions and social policy. Therefore, to better understand these portrayals, this study content analyzes a nationally representative sample of newspaper coverage of IPV over a two-year-period and compares this coverage to epidemiological data in order to examine the implications of the discrepancies between coverage and social reality. Stratified media outlets across the country were used to obtain a representative sample of daily newspapers based on their designated market areas, resulting in 395 IPV-related articles. Results show that newspaper framing of IPV tends to be heavily skewed toward episodic framing. In addition, there are significant differences between our data and epidemiological estimates, particularly in the coverage of homicide and use of alcohol and illegal drugs, which may skew public perceptions of risk. Implications for public perceptions and social policy are discussed.

[Seroprevalence of Trypanosoma cruzi infection in the rural population of Sucre State, Venezuela].

PubMed

García-Jordán, Noris; Berrizbeitia, Mariolga; Rodríguez, Jessicca; Concepción, Juan Luis; Cáceres, Ana; Quiñones, Wilfredo

2017-10-26

The current study aimed to determine the seroprevalence of Trypanosoma cruzi infection in Sucre State, Venezuela, and its association with epidemiological risk factors. The cluster sampling design allowed selecting 96 villages and 576 dwellings in the State's 15 municipalities. A total of 2,212 serum samples were analyzed by ELISA, HAI, and IFI. Seroprevalence in Sucre State was 3.12%. Risk factors associated with T. cruzi infection were: accumulated garbage, flooring and wall materials, type of dwelling, living in a house with wattle and daub walls and/or straw roofing, living in a house with risky walls and roofing, risky buildings and wattle and daub outbuildings, poultry inside the human dwelling, and presence of firewood. Infection was associated with individual age, and three seropositive cases were found in individuals less than 15 years of age. Sucre State has epidemiological factors that favor the risk of acquiring T. cruzi infection.

Common periodontal diseases of children and adolescents.

PubMed

Al-Ghutaimel, Hayat; Riba, Hisham; Al-Kahtani, Salem; Al-Duhaimi, Saad

2014-01-01

Background. Since 2000, studies, experiments, and clinical observations revealed high prevalence of periodontal diseases among children and adolescents. Therefore, this paper was designed to provide an update for dental practitioners on epidemiology, microbiology, pathology, prevention, diagnosis, and treatment of periodontal diseases in children and adolescents. Methods. This paper reviews the current literature concerning periodontal diseases in pediatric dentistry. It includes MEDLINE database search using key terms: "periodontal diseases in children," "Periodontal diseasesin adolescents," "periodontal diseases risk factors," "microbiology of periodontal diseases," "classification of periodontal diseases," "epidemiology of periodontal diseases," and "treatment of periodontal diseases." Articles were evaluated by title and/or abstract and relevance to pediatric dentistry. Sixty-five citations were selected by this method and by the references within the chosen articles. A review of the comprehensive textbooks on pediatric dentistry and periodontology was done. Some recommendations were based on the opinions of experienced researchers and clinicians, when data were inconclusive.

[New model of accumulation and agro-business: the ecological and epidemiological implications of the Ecuadorian cut flower production].

PubMed

Breilh, Jaime

2007-01-01

The article refers to the results of an integrative research project that aim to analyze ecosystem and human health's impacts of cut flower production in Cuencas del Rio Grande region (Cayambe and Tabacundo zones). In order to assess the complex object of study and its multiple dimensions, an interdisciplinary approach has been constructed, based on the following components: a) pesticides dynamics analysis; b) pesticides distribution and commercialization processes in the region; c) economic and anthropological transformation determinate by the flower production; d) epidemiological process of human health impacts; e) and the design of participatory, multicultural and integrative information. The research consolidated an important geo-codified data base on the impacts of cut flower production to workers, communities, aquatic systems and soils, offering evidences of the actual flower production system severe impacts and leading to a reflection about the sustainability of the productive systems and the future of the ecosystems.

Trace metals in occupationally and nonoccupationally exposed individuals.

PubMed Central

Johnson, D E; Tillery, J B; Prevost, R J

1975-01-01

An epidemiological survey was conducted in Houston, Texas on five trace metals in policemen, parking garage attendants, women living near freeways and three control groups of subjects. The controls were matched with the exposed groups for covariate information such as age, sex, smoking habits, ethnic background, socioeconomic status, hair color, and education. Each subject was sampled four times for blood, urine, hair, and feces, and these samples were analyzed for lead, cadmium, zinc, manganese, and copper. Lead and cadmium were correlated with airborne exposures but zinc, manganese and copper were not. The second part of this paper deals with a market study of platinum and palladium markets and a design of an epidemiology survey of individuals occupationally and nonoccupationally exposed to these two metals. The market survey shows that although the catalytic muffler will have a major impact on the market, it is predicted that producers can meet these demands. PMID:1157784

The hazards of hazard identification in environmental epidemiology.

PubMed

Saracci, Rodolfo

2017-08-09

Hazard identification is a major scientific challenge, notably for environmental epidemiology, and is often surrounded, as the recent case of glyphosate shows, by debate arising in the first place by the inherently problematic nature of many components of the identification process. Particularly relevant in this respect are components less amenable to logical or mathematical formalization and essentially dependent on scientists' judgment. Four such potentially hazardous components that are capable of distorting the correct process of hazard identification are reviewed and discussed from an epidemiologist perspective: (1) lexical mix-up of hazard and risk (2) scientific questions as distinct from testable hypotheses, and implications for the hierarchy of strength of evidence obtainable from different types of study designs (3) assumptions in prior beliefs and model choices and (4) conflicts of interest. Four suggestions are put forward to strengthen a process that remains in several aspects judgmental, but not arbitrary, in nature.

Helminths and HIV infection: epidemiological observations on immunological hypotheses

PubMed Central

BROWN, M; MAWA, P A; KALEEBU, P; ELLIOTT, A M

2006-01-01

Parasitic helminths have co-evolved with the mammalian immune system. Current hypotheses suggest that immunological stimulation in the presence of helminths is balanced by immuno-regulation and by the broad spectrum of mechanisms possessed by helminths for countering the host immune response. The degree to which this balance is perfected, and the mechanisms by which this is achieved, vary between helminth species; we suggest that this is reflected not only in the degree of pathology induced by helminths but also in a variety of relationships with HIV infection and HIV disease. Available epidemiological data regarding interactions between helminths and HIV are largely observational; results are variable and generally inconclusive. Well designed, controlled intervention studies are required to provide definitive information on the species-specific nature of these interactions and on the advantages, disadvantages and optimal timing of de-worming in relation to HIV infection. PMID:17042933

Parental occupation and childhood cancer: review of epidemiologic studies.

PubMed Central

Savitz, D A; Chen, J H

1990-01-01

Parental occupational exposures might affect childhood cancer in the offspring through genetic changes in the ovum or sperm or through transplacental carcinogenesis. The 24 published epidemiologic studies of this association have all used case-control designs, with controls generally selected from birth certificates or from general population sampling. Occupational exposures were inferred from job titles on birth certificates or through interviews. A large number of occupation-cancer associations have been reported, many of which were not addressed or not confirmed in other studies. Several associations have been found with consistency: paternal exposures in hydrocarbon-associated occupations, the petroleum and chemical industries, and especially paint exposures have been associated with brain cancer; paint exposures have also been linked to leukemias. Maternal exposures have received much less attention, but studies have yielded strongly suggestive results linking a variety of occupational exposures to leukemia and brain cancer. The primary limitations in this literature are the inaccuracy inherent in assigning exposure based on job title alone and imprecision due to limited study size. Although no etiologic associations have been firmly established by these studies, the public health concerns and suggestive data warrant continued research. PMID:2272330

Evaluation of the Association between Persistent Organic ...

EPA Pesticide Factsheets

Background: Diabetes is a major threat to public health in the United States and worldwide. Understanding the role of environmental chemicals in the development or progression of diabetes is an emerging issue in environmental health.Objective: We assessed the epidemiologic literature for evidence of associations between persistent organic pollutants (POPs) and type 2 diabetes.Methods: Using a PubMed search and reference lists from relevant studies or review articles, we identified 72 epidemiological studies that investigated associations of persistent organic pollutants (POPs) with diabetes. We evaluated these studies for consistency, strengths and weaknesses of study design (including power and statistical methods), clinical diagnosis, exposure assessment, study population characteristics, and identification of data gaps and areas for future research.Conclusions: Heterogeneity of the studies precluded conducting a meta-analysis, but the overall evidence is sufficient for a positive association of some organochlorine POPs with type 2 diabetes. Collectively, these data are not sufficient to establish causality. Initial data mining revealed that the strongest positive correlation of diabetes with POPs occurred with organochlorine compounds, such as trans-nonachlor, dichlorodiphenyldichloroethylene (DDE), polychlorinated biphenyls (PCBs), and dioxins and dioxin-like chemicals. There is less indication of an association between other nonorganochlorine POPs, such as