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Contradictory Results from Epidemiologic Studies Are Uncommon: Understanding the Nuances of Research
Introduction:
The field of epidemiology, crucial for understanding disease patterns and public health interventions, often faces scrutiny regarding the reliability of its findings. A common misconception is that epidemiological studies frequently produce contradictory results, leading to confusion and distrust. However, this notion is largely inaccurate. While inconsistencies can and do arise, they are far less prevalent than often perceived. This post will delve into why contradictory results from epidemiological studies are actually uncommon, exploring the reasons behind apparent discrepancies and highlighting the rigorous methodologies employed to minimize conflicting findings. We'll examine the challenges inherent in epidemiological research, the importance of study design, and the critical role of meta-analysis in synthesizing evidence. By the end, you'll have a clearer understanding of the robustness and reliability of epidemiological research.
H2: The Myth of Frequent Contradictory Findings
The idea that epidemiological studies frequently clash is fueled by selective reporting, media sensationalism, and a misunderstanding of the scientific process itself. Individual studies, especially those with small sample sizes or limitations in methodology, might yield results that appear to contradict others. However, the overall body of epidemiological evidence, when properly synthesized, usually reveals a consistent pattern. The emphasis on single studies, often those with headline-grabbing but potentially flawed conclusions, overshadows the broader consensus established through numerous, well-designed investigations.
H2: Sources of Apparent Discrepancies in Epidemiological Research
Several factors contribute to the appearance of conflicting results, even when the underlying reality is a more coherent picture:
H3: Study Design and Methodology:
Variations in study design (cohort, case-control, cross-sectional) and methodological approaches (data collection techniques, statistical analyses) can lead to different findings. A poorly designed study, for instance, may suffer from selection bias, confounding variables, or measurement error, leading to unreliable results. These discrepancies are not contradictions in the true sense, but rather reflections of methodological limitations.
H3: Population Differences:
Studies conducted in different populations (e.g., varying age, ethnicity, geographic location) may yield diverse results due to genetic predisposition, environmental exposures, and lifestyle differences. What might hold true for one population may not be entirely applicable to another. These are not contradictory findings but rather illustrate the complexity of human health.
H3: Confounding Factors:
Epidemiological studies often struggle with confounding factors – variables that influence both the exposure and the outcome, masking the true association. Failure to adequately adjust for these confounders can lead to inaccurate conclusions, making results seem discordant.
H3: Publication Bias:
The tendency for studies with positive or statistically significant results to be published more readily than those with negative or null findings creates a skewed perception of the evidence. This publication bias distorts the overall picture and can give a false impression of widespread contradiction.
H2: The Role of Meta-Analysis and Systematic Reviews
Meta-analyses and systematic reviews play a crucial role in resolving apparent contradictions. These approaches systematically synthesize the evidence from multiple studies, assessing their quality and weighting them appropriately. By combining data from numerous investigations, they provide a more robust and comprehensive overview, often revealing a consistent pattern even when individual studies show variations. These meta-analyses offer a much more reliable picture than relying on individual study results in isolation.
H2: The Importance of Replicability and Validation
A key aspect of robust scientific research is replicability. Well-conducted epidemiological studies should ideally be reproducible by independent researchers. If a study's results cannot be replicated, it casts doubt on its validity. However, it's crucial to remember that not all studies aim for perfect replication; variations in population, context, and methodology are sometimes expected. Validation through multiple studies, using different approaches and populations, strengthens the overall body of evidence.
Conclusion:
While apparent contradictions might emerge in individual epidemiological studies, a closer examination typically reveals underlying reasons for these discrepancies. Methodological limitations, population differences, confounding factors, and publication bias often contribute to this perceived inconsistency. However, the cumulative evidence from numerous well-conducted studies, analyzed through systematic reviews and meta-analyses, consistently reveals a coherent pattern. Thus, the statement "contradictory results from epidemiologic studies are uncommon" is generally accurate, reflecting the robust and valuable contributions of epidemiological research to public health.
FAQs:
1. Q: How can I determine if an epidemiological study is reliable? A: Look for a clearly defined research question, a robust methodology (including sample size and statistical analysis), attention to potential confounders, and transparency in reporting. Peer-reviewed publication in reputable journals is also a positive indicator.
2. Q: Why are some epidemiological studies controversial? A: Controversies often arise from limitations in study design, interpretation of results (particularly in observational studies), or conflicts of interest. Furthermore, societal and political factors can influence the reception and interpretation of epidemiological findings.
3. Q: What role does expert opinion play in interpreting epidemiological data? A: While expert opinion is valuable, it should not override the evidence from well-conducted studies. Expert consensus, however, informed by rigorous evidence synthesis, can offer valuable guidance.
4. Q: How can the public better understand and interpret epidemiological findings? A: Seek information from reliable sources such as government health agencies and reputable scientific journals. Be critical of sensationalized reporting and focus on the broader body of evidence rather than isolated studies.
5. Q: What are some examples of large-scale epidemiological studies that have consistently yielded reliable results? A: Studies on the link between smoking and lung cancer, the effectiveness of vaccination programs, and the impact of dietary factors on cardiovascular health are all examples of epidemiological research that has generated robust and consistently reliable findings across numerous independent investigations.
| contradictory results from epidemiologic studies are uncommon: Textbook of Uncommon Cancer Derek Raghavan, Manmeet S. Ahluwalia, Charles D. Blanke, Jubilee Brown, Edward S. Kim, Gregory H. Reaman, Mikkael A. Sekeres, 2017-03-09 The fifth edition of the only comprehensive text dealing exclusively with rare or infrequently encountered malignancies in adults and children is an essential resource for any clinical oncologist. Encompasses all the information needed to diagnose and manage uncommon cancers, an area where advice and guidance is typically scarce Fully revised with new material and an evidence-based, teach-by-example approach Provides insight on real-world decision making in the clinical setting Edited and authored by a highly experienced and senior team of medical oncologists, radiation oncologists, and other specialists, giving a balanced and complete overview Extensively illustrated in full color throughout, including heat maps to show gene expression |
| contradictory results from epidemiologic studies are uncommon: Epidemiological Research: Terms and Concepts O. S. Miettinen, 2011-04-22 The book is organized so as to address in separate sections first the preparatory topics of medicine (clinical and epidemiological), science in general, and statistics (mathematical); then topics of epidemiological research proper; and, finally, topics of ‘meta-epidemiological’ clinical research. In those two main sections, a further grouping is based on the distraction between objects and methods of study. In this framework, the particular topics are addressed both descriptively and quasi-prescriptively, commonly with a number of explicatory annotations. This book is intended to serve as a handbook for whomever is, in whatever way, concerned with epidemiological or ‘meta-epidemiological’ clinical research. But besides this, it is also intended to serve as a textbook for students in introductory courses on ‘epidemiological’ research – to which end there is a suggested hierarchy of the concepts that might reasonably be covered. |
| contradictory results from epidemiologic studies are uncommon: Concepts of Epidemiology Raj S. Bhopal, 2016 First edition published in 2002. Second edition published in 2008. |
| contradictory results from epidemiologic studies are uncommon: Measuring Psychosocial Variables in Epidemiologic Studies of Cardiovascular Disease , 1985 |
| contradictory results from epidemiologic studies are uncommon: Uncommon Causes of Stroke Julien Bogousslavsky, Louis R. Caplan, 2001-05-24 An essential resource for diagnosis and treatment of stroke patients outside the usual clinical categories. |
| contradictory results from epidemiologic studies are uncommon: The Global Burden of Disease Christopher J. L. Murray, Alan D. Lopez, 1996 The Global Burden of Disease (GBD) provides systematic epidemiological estimates for an unprecedented 150 major health conditions. The GBD provides indispensable global and regional data for health planning, research, and education. |
| contradictory results from epidemiologic studies are uncommon: Veterinary Oncology Robert Klopfleisch, 2016-10-24 This highly readable textbook provides a comprehensive but concise overview of the principles of oncogenesis in veterinary medicine, discussing selected tumors in domestic animals in detail, and addressing cancer diagnostics and therapy. All chapters are illustrated with histological and radiological images to enhance readers’ understanding. Accordingly, the book is a must-have reference guide for all graduate and advanced undergraduate students in Veterinary Medicine with a special interest in oncology. |
| contradictory results from epidemiologic studies are uncommon: Possible Health Effects of Exposure to Residential Electric and Magnetic Fields National Research Council, Division on Earth and Life Studies, Commission on Life Sciences, Committee on the Possible Effects of Electromagnetic Fields on Biologic Systems, 1997-03-18 Can the electric and magnetic fields (EMF) to which people are routinely exposed cause health effects? This volume assesses the data and draws conclusions about the consequences of human exposure to EMF. The committee examines what is known about three kinds of health effects associated with EMF: cancer, primarily childhood leukemia; reproduction and development; and neurobiological effects. This book provides a detailed discussion of hazard identification, dose-response assessment, exposure assessment, and risk characterization for each. Possible Health Effects of Exposure to Residential Electric and Magnetic Fields also discusses the tools available to measure exposure, common types of exposures, and what is known about the effects of exposure. The committee looks at correlations between EMF exposure and carcinogenesis, mutagenesis, neurobehavioral effects, reproductive and developmental effects, effects on melatonin and other neurochemicals, and effects on bone healing and stimulated cell growth. |
| contradictory results from epidemiologic studies are uncommon: Diet and Health National Research Council, Division on Earth and Life Studies, Commission on Life Sciences, Committee on Diet and Health, 1989-01-01 Diet and Health examines the many complex issues concerning diet and its role in increasing or decreasing the risk of chronic disease. It proposes dietary recommendations for reducing the risk of the major diseases and causes of death today: atherosclerotic cardiovascular diseases (including heart attack and stroke), cancer, high blood pressure, obesity, osteoporosis, diabetes mellitus, liver disease, and dental caries. |
| contradictory results from epidemiologic studies are uncommon: Umbrella Reviews Giuseppe Biondi-Zoccai, 2016-02-03 This book is an ideal guide to umbrella reviews, overviews of reviews, and meta-epidemiologic studies for evidence synthesis. Research is conducted at different levels: primary research consists of original studies while secondary research comprises qualitative reviews, systematic reviews, and meta-analyses. Recently, a novel further level of research has been introduced, based on the analysis and pooling of reviews and meta-analysis. This book is the first to focus solely on this new type of research design, which permits a comprehensive and powerful synthesis of scientific evidence in medicine as well as in many other fields in order to inform decision-making. All aspects are covered, including review design and registration, the searching, abstracting, appraisal, and synthesis of evidence, the appraisal of moderators and confounders, and state of the art reporting. Case studies in a range of medical specialties are then presented. The hands-on approach of the book, written by a multinational team of experts, will enable the reader to interpret and independently conduct umbrella reviews. |
| contradictory results from epidemiologic studies are uncommon: Hyping Health Risks Geoffrey Kabat, 2011-12-06 The media constantly bombard us with news of health hazards lurking in our everyday lives, but many of these hazards turn out to have been greatly overblown. According to author and epidemiologist Geoffrey C. Kabat, this hyping of low-level environmental hazards leads to needless anxiety and confusion on the part of the public concerning which exposures have important effects on health and which are likely to have minimal or no effect. Kabat approaches health scares as social facts and shows that a variety of factors can contribute to the inflating of a hazard. These include skewed reporting by the media, but also, surprisingly, the actions of researchers who may emphasize certain findings while ignoring others; regulatory and health agencies eager to show their responsiveness to the health concerns of the public; and politicians and advocates with a stake in a particular outcome. By means of four case studies, Kabat demonstrates how a powerful confluence of interests can lead to overstating or distorting the scientific evidence. He considers the health risks of pollutants such as DDT as a cause of breast cancer, electromagnetic fields from power lines, radon within residences, and secondhand tobacco smoke. Tracing the trajectory of each of these hazards from its initial emergence to the present, Kabat shows how publication of more rigorous studies and critical assessments ultimately help put hazards in perspective. |
| contradictory results from epidemiologic studies are uncommon: Introduction to Occupational Epidemiology Sven Hernberg, 1992 This new book provides a comprehensive introduction to occupational epidemiology. The text is straightforward and easy to understand; numerous examples help illustrate the concepts being presented. Topics discussed include a comparison between nonexperimental research and experimental research, control measures used in epidemiological research, data sources, epidemiological study designs, validity problems and generalization, procedures for writing a study protocol, and ethical aspects. The book also looks at specific problems that may be encountered during the epidemiological study of cancer, coronary heart disease, chronic respiratory diseases, musculoskeletal disorders, and psychosocial problems. The book's final chapter provides an orientation of the interpretation of epidemiological studies and discusses reasons for false negative and false positive results. Introduction to Occupational Epidemiology is an excellent book for researchers beginning epidemiological studies, students in occupational health fields, occupational health physicians, hygienists, sociologists, ergonomists, public health personnel, and decision makers in public and occupational health. |
| contradictory results from epidemiologic studies are uncommon: Making Eye Health a Population Health Imperative National Academies of Sciences, Engineering, and Medicine, Health and Medicine Division, Board on Population Health and Public Health Practice, Committee on Public Health Approaches to Reduce Vision Impairment and Promote Eye Health, 2017-01-15 The ability to see deeply affects how human beings perceive and interpret the world around them. For most people, eyesight is part of everyday communication, social activities, educational and professional pursuits, the care of others, and the maintenance of personal health, independence, and mobility. Functioning eyes and vision system can reduce an adult's risk of chronic health conditions, death, falls and injuries, social isolation, depression, and other psychological problems. In children, properly maintained eye and vision health contributes to a child's social development, academic achievement, and better health across the lifespan. The public generally recognizes its reliance on sight and fears its loss, but emphasis on eye and vision health, in general, has not been integrated into daily life to the same extent as other health promotion activities, such as teeth brushing; hand washing; physical and mental exercise; and various injury prevention behaviors. A larger population health approach is needed to engage a wide range of stakeholders in coordinated efforts that can sustain the scope of behavior change. The shaping of socioeconomic environments can eventually lead to new social norms that promote eye and vision health. Making Eye Health a Population Health Imperative: Vision for Tomorrow proposes a new population-centered framework to guide action and coordination among various, and sometimes competing, stakeholders in pursuit of improved eye and vision health and health equity in the United States. Building on the momentum of previous public health efforts, this report also introduces a model for action that highlights different levels of prevention activities across a range of stakeholders and provides specific examples of how population health strategies can be translated into cohesive areas for action at federal, state, and local levels. |
| contradictory results from epidemiologic studies are uncommon: How Tobacco Smoke Causes Disease United States. Public Health Service. Office of the Surgeon General, 2010 This report considers the biological and behavioral mechanisms that may underlie the pathogenicity of tobacco smoke. Many Surgeon General's reports have considered research findings on mechanisms in assessing the biological plausibility of associations observed in epidemiologic studies. Mechanisms of disease are important because they may provide plausibility, which is one of the guideline criteria for assessing evidence on causation. This report specifically reviews the evidence on the potential mechanisms by which smoking causes diseases and considers whether a mechanism is likely to be operative in the production of human disease by tobacco smoke. This evidence is relevant to understanding how smoking causes disease, to identifying those who may be particularly susceptible, and to assessing the potential risks of tobacco products. |
| contradictory results from epidemiologic studies are uncommon: Measuring psychosocial variables in epidemiologic studies of cardiovascular disease , 1985 |
| contradictory results from epidemiologic studies are uncommon: Molecular Epidemiology Paul A. Schulte, Frederica P. Perera, 2012-12-02 This book will serve as a primer for both laboratory and field scientists who are shaping the emerging field of molecular epidemiology. Molecular epidemiology utilizes the same paradigm as traditional epidemiology but uses biological markers to identify exposure, disease or susceptibility. Schulte and Perera present the epidemiologic methods pertinent to biological markers. The book is also designed to enumerate the considerations necessary for valid field research and provide a resource on the salient and subtle features of biological indicators. |
| contradictory results from epidemiologic studies are uncommon: Social Epidemiology Lisa F. Berkman, Ichiro Kawachi, 2000-03-09 This book shows the important links between social conditions and health and begins to describe the processes through which these health inequalities may be generated. It reviews a range of methodologies that could be used by health researchers in this field and proposes innovative future research directions. |
| contradictory results from epidemiologic studies are uncommon: The Health Consequences of Involuntary Exposure to Tobacco Smoke , 2006 This Surgeon General's report returns to the topic of the health effects of involuntary exposure to tobacco smoke. The last comprehensive review of this evidence by the Department of Health and Human Services (DHHS) was in the 1986 Surgeon General's report, The Health Consequences of Involuntary Smoking, published 20 years ago this year. This new report updates the evidence of the harmful effects of involuntary exposure to tobacco smoke. This large body of research findings is captured in an accompanying dynamic database that profiles key epidemiologic findings, and allows the evidence on health effects of exposure to tobacco smoke to be synthesized and updated (following the format of the 2004 report, The Health Consequences of Smoking). The database enables users to explore the data and studies supporting the conclusions in the report. The database is available on the Web site of the Centers for Disease Control and Prevention (CDC) at http://www.cdc.gov/tobacco. |
| contradictory results from epidemiologic studies are uncommon: Cellular and Molecular Toxicology of Nanoparticles Quaiser Saquib, Mohammad Faisal, Abdulaziz A. Al-Khedhairy, Abdulrahman A. Alatar, 2018-02-16 This edited book is a compilation of findings on the molecular and cellular toxicity of nanoparticles (NPs) in animal cell, human cells, invertebrates. The varied selection of test models will provide better understanding about the horizon of NPs toxicity. Interaction of NPs with cells and its organelles can induce toxicological consequences, including transcriptional and translational alterations, DNA damage, cytotoxicity, oxidative stress, mitochondrial dysfunction and cell death. NPs can get internalized in cells through phagocytosis, macropinocytosis, receptor-mediated endocytosis and passive penetration, which can affect varied cell types. Readers will be benefited with the compilations on basic and molecular facet of NPs toxicity. The chapters will provide a comprehensive information on the state-of-the-art methodologies. The application of toxicogenomic approaches, which is already established in nanotoxicology, has been given special consideration to unravel the toxicodynamics of nanomaterials. Among these approaches, the high-throughput RNA sequencing (RNA-Seq), which is able to build a complete map of transcriptome across different cell types and perturbations upon NPs exposure has been included. The readers are also introduced to the less studied topic on the adsorption of biomolecules (mainly proteins) on the NPs surface, constituting the so-called “biomolecular corona”. The book has been designed for scientists engaged in NPs toxicity research. Nonetheless, it should be of interest to a variety of scientific disciplines including marine biology, environmental pollution, genetics, pharmacology, medicine, drug and food material sciences, consumer products. Also, the compilations will be of interest to the environmental watchdogs, federal regulators, risk assessors and the policy makers. |
| contradictory results from epidemiologic studies are uncommon: CURRENT Diagnosis & Treatment Occupational & Environmental Medicine, 6th Edition Joseph LaDou, Robert Harrison, 2021-05-06 New edition of a comprehensive text: an ideal resource for the occupational health professional! An updated and comprehensive guide to occupational and environmental injuries and illnesses, their diagnosis and treatment, and preventive measures in the workplace and community. Complete and concise, this clinically focused book is the go-to reference for health care professionals in all specialties who diagnose and treat acute and chronic occupational and environmental injuries and illnesses. In addition to clinical management and toxicology, the text covers important aspects of multidisciplinary occupational health and safety practice including ethical principles, disability management, workers’ compensation, medical monitoring, and health risk assessment. This new edition features new chapters on the impact of climate change on workers, the changing nature of work, Total Worker Health, workplace violence, pediatric environmental health, genetic toxicology and responder safety and health latest approaches to prevent workplace-related injuries through the application of ergonomic principles updated practical information on the toxic properties and clinical manifestations of industrial materials and environmental agents. |
| contradictory results from epidemiologic studies are uncommon: Depression and Diabetes Wayne Katon, Mario Maj, Norman Sartorius, 2011-06-09 In recent years, there has been a growing awareness of the multiple interrelationships between depression and various physical diseases. The WPA is providing an update of currently available evidence on these interrelationships by the publication of three books, dealing with the comorbidity of depression with diabetes, heart disease and cancer. Depression is a frequent and serious comorbid condition in diabetes, which adversely affects quality of life and the long-term prognosis. Co-occurrent depression presents peculiar clinical challenges, making both conditions harder to manage. Depression and Diabetes is the first book devoted to the interaction between these common disorders. World leaders in diabetes, depression and public health synthesize current evidence, including some previously unpublished data, in a concise, easy-to-read format. They provide an overview of the epidemiology, pathogenesis, medical costs, management, and public health and cultural implications of the comorbidity between depression and diabetes. The book describes how the negative consequences of depression in diabetes could be avoided, given that effective depression treatments for diabetic patients are available. Its practical approach makes the book ideal for all those involved in the management of these patients: psychiatrists, psychologists, diabetologists, general practitioners, diabetes specialist nurses and mental health nurses. |
| contradictory results from epidemiologic studies are uncommon: Beyond One Health John A. Herrmann, Yvette J. Johnson-Walker, 2018-04-10 Tackling One Health from a multi-disciplinary perspective, this book offers in-depth insight into how our health and the health of every living creature and our ecosystem are all inextricably connected. Presents critical population health topics, written by an international group of experts Addresses the technical aspects of the subject Offers potential policy solutions to help mitigate current threats and prevent additional threats from occurring |
| contradictory results from epidemiologic studies are uncommon: Marijuana As Medicine? Institute of Medicine, Janet Joy, Alison Mack, 2000-12-30 Some people suffer from chronic, debilitating disorders for which no conventional treatment brings relief. Can marijuana ease their symptoms? Would it be breaking the law to turn to marijuana as a medication? There are few sources of objective, scientifically sound advice for people in this situation. Most books about marijuana and medicine attempt to promote the views of advocates or opponents. To fill the gap between these extremes, authors Alison Mack and Janet Joy have extracted critical findings from a recent Institute of Medicine study on this important issue, interpreting them for a general audience. Marijuana As Medicine? provides patientsâ€as well as the people who care for themâ€with a foundation for making decisions about their own health care. This empowering volume examines several key points, including: Whether marijuana can relieve a variety of symptoms, including pain, muscle spasticity, nausea, and appetite loss. The dangers of smoking marijuana, as well as the effects of its active chemical components on the immune system and on psychological health. The potential use of marijuana-based medications on symptoms of AIDS, cancer, multiple sclerosis, and several other specific disorders, in comparison with existing treatments. Marijuana As Medicine? introduces readers to the active compounds in marijuana. These include the principal ingredient in Marinol, a legal medication. The authors also discuss the prospects for developing other drugs derived from marijuana's active ingredients. In addition to providing an up-to-date review of the science behind the medical marijuana debate, Mack and Joy also answer common questions about the legal status of marijuana, explaining the conflict between state and federal law regarding its medical use. Intended primarily as an aid to patients and caregivers, this book objectively presents critical information so that it can be used to make responsible health care decisions. Marijuana As Medicine? will also be a valuable resource for policymakers, health care providers, patient counselors, medical faculty and studentsâ€in short, anyone who wants to learn more about this important issue. |
| contradictory results from epidemiologic studies are uncommon: Investigation of Sudden Infant Death Syndrome Marta C. Cohen, Irene B. Scheimberg, J. Bruce Beckwith, Fern R. Hauck, 2019-06-13 A scientifically rigorous, multidisciplinary approach to Sudden Infant Death Syndrome, for practitioners, researchers and families alike. |
| contradictory results from epidemiologic studies are uncommon: Journal of the National Cancer Institute , 2006 |
| contradictory results from epidemiologic studies are uncommon: Comparative Quantification of Health Risks: Sexual and reproductive health Majid Ezzati, 2004 Provides a comprehensive assessment of the scientific evidence on prevalence and the resulting health effects of a range of exposures that are know to be hazardous to human health, including childhood and maternal undernutrition, nutritional and physiological risk factors for adult health, addictive substances, sexual and reproductive health risks, and risks in the physical environments of households and communities, as well as among workers. This book is the culmination of over four years of scientific equiry and data collection, know as the comparative risk assessment (CRA) project. |
| contradictory results from epidemiologic studies are uncommon: National Toxicology Program United States. Congress. House. Committee on Science and Technology. Subcommittee on Investigations and Oversight, 1981 |
| contradictory results from epidemiologic studies are uncommon: Geriatric Neurology Anil K. Nair, Marwan N. Sabbagh, 2014-03-06 Aging affects neurological function leading to neurological disease As society grows older, so do the neurological problems associated with aging. These can be new neurological deficits due to the aging process itself, or the effect of aging on already existing neurological conditions. Neurologists will spend increasing amounts of time managing patients with age-related neurological complications. Geriatric Neurology brings together the wisdom of world-leading experts. They have crafted a new textbook to define this emerging subspecialty from basic science through clinical assessment and medical management to social aspects of patient care. Geriatric Neurology covers: The aging brain in neurology Assessment of the geriatric neurology patient Neurological conditions in the elderly Therapeutics for the geriatric neurology patient Management issues beyond therapeutics Comprehensive in scope but with practical focus for effective patient care, Geriatric Neurology provides top-of-class guidance for the management of elderly patients with neurological disorders. |
| contradictory results from epidemiologic studies are uncommon: Clinical Epidemiology Alvan R. Feinstein, 1985 |
| contradictory results from epidemiologic studies are uncommon: Dietary Reference Intakes for Vitamin C, Vitamin E, Selenium, and Carotenoids Institute of Medicine, Food and Nutrition Board, Standing Committee on the Scientific Evaluation of Dietary Reference Intakes, Subcommittee on Interpretation and Uses of Dietary Reference Intakes, Subcommittee on Upper Reference Levels of Nutrients, Panel on Dietary Antioxidants and Related Compounds, 2000-08-27 This volume is the newest release in the authoritative series of quantitative estimates of nutrient intakes to be used for planning and assessing diets for healthy people. Dietary Reference Intakes (DRIs) is the newest framework for an expanded approach developed by U.S. and Canadian scientists. This book discusses in detail the role of vitamin C, vitamin E, selenium, and the carotenoids in human physiology and health. For each nutrient the committee presents what is known about how it functions in the human body, which factors may affect how it works, and how the nutrient may be related to chronic disease. Dietary Reference Intakes provides reference intakes, such as Recommended Dietary Allowances (RDAs), for use in planning nutritionally adequate diets for different groups based on age and gender, along with a new reference intake, the Tolerable Upper Intake Level (UL), designed to assist an individual in knowing how much is too much of a nutrient. |
| contradictory results from epidemiologic studies are uncommon: Environmental Issues in Primary Care Barbara S. Murdock, 1994-05 Provides current information on environmental health issues related to air, land and water quality. Offers accessible information on human exposures, health effects, intervention for specific environmental contaminants, case studies and suggested readings. Written and reviewed by experts, this report can help put the puzzling pieces of environmentally-related disease into place. Charts, tables, graphs and drawings. |
| contradictory results from epidemiologic studies are uncommon: Ethical Conduct of Clinical Research Involving Children Institute of Medicine, Board on Health Sciences Policy, Committee on Clinical Research Involving Children, 2004-07-09 In recent decades, advances in biomedical research have helped save or lengthen the lives of children around the world. With improved therapies, child and adolescent mortality rates have decreased significantly in the last half century. Despite these advances, pediatricians and others argue that children have not shared equally with adults in biomedical advances. Even though we want children to benefit from the dramatic and accelerating rate of progress in medical care that has been fueled by scientific research, we do not want to place children at risk of being harmed by participating in clinical studies. Ethical Conduct of Clinical Research Involving Children considers the necessities and challenges of this type of research and reviews the ethical and legal standards for conducting it. It also considers problems with the interpretation and application of these standards and conduct, concluding that while children should not be excluded from potentially beneficial clinical studies, some research that is ethically permissible for adults is not acceptable for children, who usually do not have the legal capacity or maturity to make informed decisions about research participation. The book looks at the need for appropriate pediatric expertise at all stages of the design, review, and conduct of a research project to effectively implement policies to protect children. It argues persuasively that a robust system for protecting human research participants in general is a necessary foundation for protecting child research participants in particular. |
| contradictory results from epidemiologic studies are uncommon: Surgical Arithmetic Lawrence Rosenberg, Lawrence Joseph, Alan Barkun, 2000-01-01 This book is intended for the practicing surgeon. It is designed to offer practical insights into the essentials of an epidemiological, statistical and outcomes-based approach to surgical practice. Surgeons are invited to begin to develop the requisite skills that will allow them to communicate effectively with their colleagues in epidemiology and |
| contradictory results from epidemiologic studies are uncommon: Index Medicus , 2003 Vols. for 1963- include as pt. 2 of the Jan. issue: Medical subject headings. |
| contradictory results from epidemiologic studies are uncommon: Finding What Works in Health Care Institute of Medicine, Board on Health Care Services, Committee on Standards for Systematic Reviews of Comparative Effectiveness Research, 2011-07-20 Healthcare decision makers in search of reliable information that compares health interventions increasingly turn to systematic reviews for the best summary of the evidence. Systematic reviews identify, select, assess, and synthesize the findings of similar but separate studies, and can help clarify what is known and not known about the potential benefits and harms of drugs, devices, and other healthcare services. Systematic reviews can be helpful for clinicians who want to integrate research findings into their daily practices, for patients to make well-informed choices about their own care, for professional medical societies and other organizations that develop clinical practice guidelines. Too often systematic reviews are of uncertain or poor quality. There are no universally accepted standards for developing systematic reviews leading to variability in how conflicts of interest and biases are handled, how evidence is appraised, and the overall scientific rigor of the process. In Finding What Works in Health Care the Institute of Medicine (IOM) recommends 21 standards for developing high-quality systematic reviews of comparative effectiveness research. The standards address the entire systematic review process from the initial steps of formulating the topic and building the review team to producing a detailed final report that synthesizes what the evidence shows and where knowledge gaps remain. Finding What Works in Health Care also proposes a framework for improving the quality of the science underpinning systematic reviews. This book will serve as a vital resource for both sponsors and producers of systematic reviews of comparative effectiveness research. |
| contradictory results from epidemiologic studies are uncommon: Carcinogenesis Abstracts , 1978 |
| contradictory results from epidemiologic studies are uncommon: Canadian Arctic Contaminants Assessment Report Northern Contaminants Program (Canada), 2003 |
| contradictory results from epidemiologic studies are uncommon: Mandell, Douglas, and Bennett's Principles and Practice of Infectious Diseases John E. Bennett, MD, MACP, Raphael Dolin, MD, Martin J. Blaser, MD, 2014-08-28 After thirty five years, Mandell, Douglas, and Bennett’s Principles and Practice of Infectious Diseases, 8th Edition is still the reference of choice for comprehensive, global guidance on diagnosing and treating the most challenging infectious diseases. Drs. John E. Bennett and Raphael Dolin along with new editorial team member Dr. Martin Blaser have meticulously updated this latest edition to save you time and to ensure you have the latest clinical and scientific knowledge at your fingertips. With new chapters, expanded and updated coverage, increased worldwide perspectives, and many new contributors, Mandell, Douglas, and Bennett’s Principles and Practice of Infectious Diseases, 8th Edition helps you identify and treat whatever infectious disease you see. Get the answers to questions you have with more in-depth coverage of epidemiology, etiology, pathology, microbiology, immunology, and treatment of infectious agents than you'll find in any other infectious disease resource. Find the latest diagnoses and treatments for currently recognized and newly emerging infectious diseases, such as those caused by avian and swine influenza viruses. Put the latest knowledge to work in your practice with new or completely revised chapters on influenza (new pandemic strains); new Middle East respiratory syndrome (MERS) virus; probiotics; antibiotics for resistant bacteria; antifungal drugs; new antivirals for hepatitis B and C; Clostridium difficile treatment; sepsis; advances in HIV prevention and treatment; viral gastroenteritis; Lyme disease; Helicobacter pylori; malaria; infections in immunocompromised hosts; immunization (new vaccines and new recommendations); and microbiome. Benefit from fresh perspectives and global insights from an expanded team of international contributors. Find and grasp the information you need easily and rapidly with newly added chapter summaries. These bulleted templates include diagnosis, therapy, and prevention and are designed as a quick summary of the chapter and to enhance relevancy in search and retrieval on Expert Consult. Stay current on Expert Consult with a thorough and regularly scheduled update program that ensures access to new developments in the field, advances in therapy, and timely information. Access the information you need easily and rapidly with new succinct chapter summaries that include diagnosis, therapy, and prevention. Experience clinical scenarios with vivid clarity through a richly illustrated, full-color format that includes 1500 photographs for enhanced visual guidance. |
| contradictory results from epidemiologic studies are uncommon: Schizophrenia Bulletin , 2004 |
| contradictory results from epidemiologic studies are uncommon: Epidemiology Kenneth J. Rothman, 2012-06-21 The second edition of this essential introduction to epidemiology presents the core concepts in a unified approach that aims to cut through the fog and elucidate the fundamental concepts. |
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Interpretation of epidemiological studies - International …
Interpretation of epidemiological studies. In epidemiology, studies are carried out to identify exposures that may affect the risk of developing a certain disease or other health-related out …
Confidence Limit Analyses Should Replace Power Calculations …
Keywords: confidence intervals, epidemiology, negative studies, study power, interpretation, data analysis. In evaluating the results of a "negative" epidemiologic study, it is common to consider …
Observational Studies and Bias in Epidemiology - College Board
Bias, as defined in epidemiology, is an error in design or execu-tion of a study, which produces results that are consistently distorted in one direction because of nonrandom factors. Bias can …
Methodologic Standards and Contradictory Results in Case …
reasoning used in prospective (cohort) studies, the retrospective case-control method for the study of disease etiology has become epidemiologically popular and sanctioned by authorities …
Contradictory Results From Epidemiologic Studies Are …
Schulte and Perera present the epidemiologic methods pertinent to biological markers The book is also designed to enumerate the considerations necessary for valid field research and provide a …
Contradictory Results From Epidemiologic Studies Are …
delve into why contradictory results from epidemiological studies are actually uncommon, exploring the reasons behind apparent discrepancies and highlighting the rigorous …
To Use or Not to Use the Odds Ratio in Epidemiologic …
Abstract. This paper argues that the use of the odds sampling approach permits the incidence ratio and ratio parameter in epidemiology needs to be consid- difference measures to be …
Contradictory Results From Epidemiologic Studies Are …
Sep 5, 2023 · Contradictory Results From Epidemiologic Studies Are Uncommon Textbook of Uncommon Cancer Derek Raghavan,Manmeet S. Ahluwalia,Charles D. Blanke,Jubilee …
TYPES OF EPIDEMIOLOGIC STUDIES (from Chapter 5 of …
Epidemiologic study types have their roots in the concepts of scientific experimentation. When epidemiologic experiments are feasible, their design is guided by principles that reduce …
Influence of exposure measurement errors on results from …
We critically evaluate how types of exposure measurement error influenced bias and precision of effect estimates to understand conditions affecting interpretation of exposure-response models …
Pitfalls in epidemiological analysis - JSTOR
tendency of research to come up with contradictory results. In the examples given below non-experimental data are assumed throughout. Furthermore, the back-ground is one of …
Negative Control Exposures in Epidemiologic Studies - JSTOR
Epidemiologic Studies To the Editor: In their excellent review on negative controls,1 Lipsitch and colleagues1 state they "are not aware of an exam ple of the use of a negative control exposure …
A Critical Review of Epidemiologic Studies of Radiofrequency …
This paper reviews studies that have assessed associations between likely exposure to radiofrequency (RF) transmissions and various types of human cancer. These studies include …
Confidence Limit Analyses Should Replace Power Calcul…
Keywords: confidence intervals, epidemiology, negative studies, study power, interpretation, data analysis. In evaluating the results of a "negative" epidemiologic study, it is common to …
The Ultimate Energizer Guide Download (book)
The Ultimate Energizer Guide Download The ultimate energizer guide download: Unlock sustainable energy levels and boost your productivity with our comprehensive guide, packed with …
Participation Rates in Epidemiologic Studies - Univ…
Participation rates for epidemiologic studies have been declining during the past 30 years with even steeper declines in recent years. This wholesale decrease in participation rate, or at the very …
Vitamin D and cancer; a contradictory problem - Res…
miri 2 Immunopathologia Persa Volume 4, Issue 2, July 2018 that sufficient vitamin D in nutrition will be a priority for men at …
Effects of Exercise on Ocular Physiology and Disease
gesting uncommon individual characteristics may be involved.28 C. AGE-RELATED MACULAR DEGENERATION One retrospective and one prospective study indicate that physical activity may …
Multiple myeloma: A review of the epidemiologic literature
We reviewed epidemiologic studies that evaluated lifestyle, dietary, occupational and environmental factors; immune function, family history and genetic factors; and the hypothesized …
Review and Meta-Analysis of Epidemiologic Studies of Ad…
epidemiologic studies from western countries generally find rates between 1% and 4% for the bipolar spectrum,3,28–31 whereas studies from Asian and African countries tend to be somewhat lower, …
Missing Outcome Data in Epidemiologic Studies
Figure 1. Causal diagrams for possible missing-data scenarios in theIPOPTrial.W denotesthecovariateshortcervix,Adenotestreat- ment with 17α-hydroxyprogesterone caproate, Y denotes preterm birth …
Levent Akduman and R. Joseph Olk - Springer
had positive skin test results. Epidemiologic Studies The epidemiology of OHS has been studied by many investigators and yet the relationship ... relatively uncommon, even in endemic …
Different Methods Contradictory Results? Rese…
cross-national research stands side by side with qualitative comparative historical studies. The results of these two modes of research diverge as much as their methods.
Challenges in interpreting study results - American De…
been epidemiologic studies that fall into two gen-eral categories: retrospective and prospective. Most retrospective studies are case-control studies, and most prospective studies are cohort studies. …
Center for Epidemiologic Studies: Depression Scale - S…
The initial CES-D study reported results from community and clinical samples (Radloff 1977). The CES-D total score distribution was relatively normal in clinical samples and positively skewed …
Polyphenols and disease risk in epidemiologic studies - Rese…
studies found protective effects of flavonols and flavones or of catechins with respect to fatal or nonfatal CAD, and reductions ofmortalityriskwereupto65%.Thesestudieswereasfollows:
Molecular epidemiology: Linking molecular scale insig…
molecular epidemiologic results by post-hoc searching through the scientific literature has led to finding biologic information that is not truly corroborating but only appears to be so (53). …
Dietary assessment methods in epidemiologic studies
3 Shim J-S et al.: Dietary assessment methods in epidemiologic studies research question. The amounts of each food consumed are es-timated in reference to a common size container …
Posttraumatic Stress Disorder and Physical Illness - Researc…
142 ANNALS NEW YORK ACADEMY OF SCIENCES KEYWORDS: posttraumatic stress disorder (PTSD); comorbid/complex PTSD; coronary heart disease (CHD); autoimmune disease; hypothalamic …
A tool for deterministic and probabilistic sensitivity ana…
N. Orsini, R. Bellocco, M. Bottai, A. Wolk, and S. Greenland 33 Misclassification of the exposure dseca(pdf options) define the sensitivity among the casesdspca(pdf options) define the specificity among …
Confounding Variables in Epidemiologic Studies: Basic…
Example 1: Some epidemiologic studies have found that poor oral health and/or tooth loss is associated with an increased risk of esophageal cancer.2,3 But does this mean that poor oral health causes …
IMI – Defining and Classifying Myopia: A Proposed Set ... - R…
Special Issue IMI – Defining and Classifying Myopia: A Proposed Set of Standards for Clinical and Epidemiologic Studies Daniel Ian Flitcroft,1 Mingguang He,2 Jost B. Jonas,3 Monica Jong,4 …
Review Article Sample Size Calculation for Epidemiologi…
the entire population if accurate enough results could be obtained by studying a subgroup of all people. For these reasons, we need to study a sample of the population. However, results vary from …
Methodologic Issues in Epidemiologic Risk Assessm…
tions observed in classical epidemiologic studies. These studies bridge the gap between laboratory experimenta tion and population-based epidemiology. Miettinen11 has remarked that …
The Affective Disorders: Results from the Epidemiolo…
The Affective Disorders: Results from the Epidemiologic Catchment Area Study ECA 17 ... Following World War II, several large-scale epidemiologic studies of chronic disease were initiated in the …
NBER WORKING PAPER SERIES RECONCILING SEEMINGLY …
on results from Oregon as the de nitive answer for how insurance expansions a ect ER utilization. Discussion of the Oregon experiment and the Massachusetts reform in the New York …
REVIEW - ResearchGate
part contradictory and controversial results on PCa risk factors in the literature. Summary A strategy to perform case--control studies based on PSA stratification is suggested to avoid
Interpretation of epidemiologic studies very …
Studies mentioning that the findings were possibly or likely affected by confounding were more frequently cited than studies with a state ment that findings were unlikely affected (median 6.3 vs. 4.0 …
Should we adjust for a confounder if empirical and t…
Theoretical confounder identification strategies select the confounders from the results of previous studies or expert knowledge. ... and theoretical criteria yield contradictory results?’’ We simulated …
Matchillg in Epidemiologic Studies: Validity and Efficie…
studies as regards validity (lack of bias) and efficiency (i.e. precision and power). Our discussions, conclusions and recommendations will depend very much on the type of epidemiologic study …
Helix-Forming Tendencies of Amino Acids in Short (Hydrox…
peptide cluster around 1, as they do in the host-guest studies, but in contrast to results with alanine-based peptides. The differences between the host-guest results and results obtained using …
Some principles for using epidemiologic study results …
Oct 3, 2023 · obtaining these parameter estimates from epidemiological studies is not always straightforward. We aim to 1) outline challenges to parameter estimation that arise due to common …
NIH Public Access Epidemiologic Studies Epide…
Overadjustment Bias and Unnecessary Adjustment in Epidemiologic Studies Enrique F. Schistermana, Stephen R. Coleb, and Robert W. Plattc aEunice Kennedy Shriver National Institute of …
Environmental Epidemiology - Jones & Bartlett Learning
cussed in Chapter 3). Smith writes, “The epidemiologic input to environmental risk assessment involves the interpretation of epidemiological studies and their application to estimat-ing the potential …
Validation of the Arabic Version of the Center for Epi…
The Center for Epidemiologic Studies Depression (CES-D) scale, which was developed in 1977 (Radloff, 1977), is a widely used measure to screen for depression in the general population.
Identification of research needs to rsolve the carcinoge…
the new studies have more sophisticated exposure assessment and thus allow for more accurate classification of TCE exposed workers (Scott and Chiu, 2006). Meta-analyses can be useful for …
Population Attributable Fraction (PAF) in Epidemiolo…
Epidemiologic Follow-up Studies TIIVISTELMÄ Maarit Laaksonen. Population Attributable Fraction (PAF) in epidemiologic follow-up studies. [Väestösyyosuus epidemiologisissa …
A Review of Epidemiologic Studies on Greenness and H…
A Review of Epidemiologic Studies on Greenness and Health: Updated Literature Through 2017 Kelvin C. Fong1 & Jaime E. Hart1,2 & Peter James3 Published online: 1 February 2018 ... Search results were …
Risk and Timing of Tuberculosis Among Close Co…
Results.— Tuberculosis was diagnosed in 158 of 4490 contacts (4%) of 718 index patients with ... Epidemiologic Studies Consortium. Close contacts were defined as persons who had shared air space …
Validation of the 10-item Center for Epidemiologic Stu…
Epidemiologic Studies Depression Scale (CESD-10) among individuals post stroke. Method: The psychometric properties of the CESD-10 were evaluated in 1219 adults ... Results: The CESD-10 was highly …
Red meat and colorectal cancer: a critical summary of …
Jun 9, 2023 · Agriculture (3). The early hypothesis-generating studies gave way to more advanced and scientifically rigorous designs, such as analytical epidemiologic case–control and prospective cohort …
Assessing Functional Status and 7 Disability in Epidemiol…
Epidemiologic research has found a long list of diseases to be associated with disability onset. The most important disease categories include musculoskeletal, cardiovascular and …
Should we adjust for a confounder if empirical and t…
Should we adjust for a confounder if empirical and theoretical criteria yield contradictory results? A simulation study Paul H. Lee School of Nursing, Hong Kong Polytechnic University.
EPIDEMIOLOGIC STUDIES ON THE ETIOLOGIC RELATIONSH…
away has been made along with studies on the disease incidence in past years, the Se contents, etc. The results of this survey showed that the 'island' was actually free from Keshan disease and that the …
Challenges and recommendations on the con…
systematic reviews and meta-analyses of environmental and occupational epidemiology studies have increased dramatically in recent years; however, the quality and utility of published reviews …
The challenges of epidemiologic translation: c…
trained in interpreting epidemiologic findings (21). For example, epidemiologists describe exposure-outcome relationships that exist on average, across populations, and …
medical progress Esophageal Cancer - The New England Jo…
Data from studies in ani- mals suggest that oxidative damage from factors such as smoking or gastroesophageal reflux, which cause inflammation, esophagitis, and increased cell turnover, may initiate
Family psychiatric screening instrument for epidemiologi…
epidemiologic and clinical studies that have at- tempted to identify risk factors for psychiatric dis- orders, such as the Epidemiologic Catchment Area (ECA) study, have excluded assessment of …
Use of previous-day recalls of physical activity and sedentar…
Results: Estimates of physical activity level (average daily rate of energy expenditure in METs) ranged from 1.53 to 1.78 in the four studies, strikingly similar to population estimates derived from …
Annals of Epidemiology - Scholars at Harvard
the design, analysis, and interpretation of future epidemiologic studies. Relevant publications were identified through electronic searches on PubMed, WorldCat, and Web of Science using …
Implications of Recent Epidemiologic Studies for th…
9 epidemiologic studies and an evaluation of whether the new observations are strong enough to support or 10 modify the LNT model as used in radiation protection today. This Report …
simulations in epidemiologic studies - JSTOR
simulations in epidemiologic studies Urban mation tanks, computers to tens and hydrants, of systems), thousands municipal and database and it is water of pumps. possible hydraulic …
The NIMH Epidemiologic Area Program - ResearchGate
Table1.—Selected EpidemiologieStudiesofMental Disordersin NorthAmerica,1950-1980: SurveyDesign Stirling County Baltimore Mldtown Manhattan NewHaven, Conn …
