Navigating research methods: critical appraisal

2016 ◽  
Keyword(s):  
Critical Appraisal ◽  
Scientific Paper ◽  
Case Control Studies ◽  
Cross Sectional ◽  
Screening Questions ◽  
Main Components ◽  
Study Designs ◽  
No Gold Standard ◽  
Internal And External Validity

This chapter discusses the role of critical appraisal as an integral part of evidence based practice. There is no gold standard for conducting critical appraisal of medical literature. Standard check lists are presented for the specific study designs (randomized controlled trials, cohort studies, case control studies and cross-sectional studies). The check lists include questions which capture four main components of a scientific paper (introduction, methods, results and discussion), and are organized as screening questions (1. Does the research address a clearly focused question?, and 2. Was the type of study appropriate?) and detailed questions focusing on the different aspects of internal and external validity.

scholarly journals Strengthening the Reporting of Observational Studies in Epidemiology (STROBE): Explanation and Elaboration. Translation to Russian

2021 ◽  
pp. 1-10
Author(s):  
Jan P. Vandenbroucke ◽  
Erik Von Elm ◽  
Douglas G. Altman ◽  
Peter C. Gotzsche ◽  
Cynthia D. Mulrow ◽  
...  
Keyword(s):  
Observational Studies ◽  
Empirical Studies ◽  
Observational Research ◽  
Case Control Studies ◽  
Quality Of Reporting ◽  
Cross Sectional ◽  
Useful Flow ◽  
Study Designs ◽  
Strobe Statement

Much medical research is observational. The reporting of observational studies is often of insufficient quality. Poor reporting hampers the assessment of the strengths and weaknesses of a study and the generalisability of its results. Taking into account empirical evidence and theoretical considerations, a group of methodologists, researchers, and editors developed the Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) recommendations to improve the quality of reporting of observational studies. The STROBE Statement consists of a checklist of 22 items, which relate to the title, abstract, introduction, methods, results and discussion sections of articles. Eighteen items are common to cohort studies, case-control studies and cross-sectional studies and four are specific to each of the three study designs. The STROBE Statement provides guidance to authors about how to improve the reporting of observational studies and facilitates critical appraisal and interpretation of studies by reviewers, journal editors and readers. This explanatory and elaboration document is intended to enhance the use, understanding, and dissemination of the STROBE Statement. The meaning and rationale for each checklist item are presented. For each item, one or several published examples and, where possible, references to relevant empirical studies and methodological literature are provided. Examples of useful flow diagrams are also included. The STROBE Statement, this document, and the associated Web site (http://www. strobe-statement.org/) should be helpful resources to improve reporting of observational research. This article is the reprint with Russian translation of the original that can be observed here: Vandenbroucke JP, von Elm E, Altman DG, Gotzsche PC, Mulrow CD, et al. Strengthening the Reporting of Observational Studies in Epidemiology (STROBE): Explanation and Elaboration. PLoS Med 2007;4(10):e297. doi:10.1371/journal.pmed.0040297

Study designs which can demonstrate and test causation

2017 ◽  
Author(s):  
Mark Elwood
Keyword(s):  
Cohort Studies ◽  
Case Control ◽  
Control Group ◽  
Case Control Studies ◽  
Retrospective Case ◽  
Community Based ◽  
Cross Sectional ◽  
Healthcare Interventions ◽  
Intervention Trials ◽  
Study Designs

This chapter presents study designs which can test and show causation. Cohort and intervention studies compare people exposed to an agent or intervention with those unexposed or less exposed. Case-control studies compare people affected by a disease or outcome with a control group of unaffected people or representing a total population. Surveys select a sample of people, not chosen by exposure or outcome. Cohort studies may be prospective or retrospective; case-control studies are retrospective; surveys are cross-sectional in time, but retrospective or prospective aspects can be added. In part two, strengths, weaknesses and applications of these designs are shown. Intervention trials, ideally randomised, are the prime method of assessing healthcare interventions; special types include crossover trials and community-based trials. Non-randomised trials are noted. The strengths and weaknesses of cohort studies, case-control studies, and surveys are shown.

Epidemiology

2017 ◽  
Author(s):  
Sadie Costello ◽  
Jennifer M. Cavallari ◽  
David H. Wegman ◽  
Marie S. O’Neill ◽  
Ellen A. Eisen
Keyword(s):  
Case Control ◽  
Case Control Studies ◽  
Cross Sectional ◽  
Information Selection ◽  
Basic Principles ◽  
Potential Source ◽  
The Common ◽  
Key Aspects ◽  
Study Designs

This chapter describes the basic principles of epidemiology, emphasizing the aspects most relevant to studies of health effects from occupational and environmental exposures. Numerous examples are provided of how epidemiology can be used to identify and quantify the relations between recent or long-term exposure and health outcomes, such as prevalence or incidence of disease, injury, or mortality. The chapter describes the common study designs, including cohort studies, case-control studies, and cross-sectional studies, with examples of their application. Key aspects of exposure assessment and characterizing and quantifying exposure, are described. The three types of bias in epidemiology, information, selection, and confounding, are defined as well as the healthy worker effect, a potential source of bias unique in occupational studies. Study designs and analytic methods that can reduce or eliminate specific types of bias are also described. Finally, the chapter provides guidance on how to interpret the results of studies, with an eye toward causal inference.

Evidence Hierarchy

2020 ◽  
pp. 61-77
Author(s):  
Julie Sin
Keyword(s):  
Case Control ◽  
Weight Of Evidence ◽  
Case Control Studies ◽  
Cause And Effect ◽  
Making Sense ◽  
Course Of Action ◽  
Basic Concepts ◽  
The Many ◽  
Study Designs

This chapter is about making sense of evidence from research studies from a commissioner and evidence-user perspective. A basic evidence hierarchy is described for general orientation to the concept that some study designs are more reliable than others in attempting to understand cause and effect, and there is orientation to the main study types in the hierarchy (randomized trials, cohort and case-control studies, etc.) Clearly it is the overall weight of evidence for a particular course of action that is important, although familiarity with basic concepts of study robustness remains useful in itself for making sense of the many items of evidence that present in everyday practice. The value of evidence from studies addressing non cause and effect type questions (for example seeking understanding about behaviours and beliefs) is discussed. The role of the evidence-user in making use of these concepts and enabling evidence informed practice is also described.

Critical appraisal

2020 ◽  
pp. 285-302
Author(s):  
Jo Thompson Coon ◽  
Rebecca Abbott
Keyword(s):  
Clinical Trials ◽  
Critical Appraisal ◽  
Case Control ◽  
Evidence Based ◽  
Case Control Studies ◽  
Cross Sectional ◽  
Worked Example ◽  
Cross Sectional Studies ◽  
Critical Appraisal Skills ◽  
Based Medicine

This chapter provides an introduction to the principles of critical appraisal and explains why critical appraisal skills are important in practice and research. Guidance is provided on how to approach the critical appraisal of different types of study including cross-sectional studies, case–control studies, cohort studies, clinical trials, systematic reviews, and qualitative studies. A worked example is provided at the end of the chapter to illustrate the process. Developing skills in critical appraisal will help readers to assess the credibility, relevance, and value of the results of research and is an essential component of practising evidence-based medicine.

Epidemiological study designs and principles of data analysis: A conceptually integrated suite of methods and techniques

2016 ◽  
Author(s):  
Raj S. Bhopal
Keyword(s):  
Risk Factors ◽  
Disease Incidence ◽  
Case Series ◽  
Epidemiological Studies ◽  
Cross Sectional Study ◽  
Natural Experiments ◽  
Case Control Studies ◽  
Cross Sectional ◽  
Common Goals ◽  
Study Designs

Epidemiological studies are unified by their common goals and by their basis in defined populations. The case series (or register-based study) includes examination of trends in deaths, cancers, notifiable diseases, and hospitalizations. Case–control studies are analysed by comparing the exposure to risk factors in cases to those in controls. In a population studied at a specific time and place (a cross-sectional study), measurements can be made of disease, the factors which may cause disease, or both simultaneously. Cohort studies produce data on disease incidence and are especially good on associations between risk factors and disease outcomes. Trials compare treated and untreated populations and are used, primarily, for information on effectiveness of health interventions. Natural experiments, including Mendelian randomization studies, may provide causal evidence. The principles for the analysis of all studies are similar. The design and interpretation should be in the context of traditional, systematic, and meta-analytic reviews.

Observational Studies

2018 ◽  
pp. 324-361
Author(s):  
Minou Djannatian ◽  
Clarissa Valim ◽  
Andre Brunoni ◽  
Felipe Fregni
Keyword(s):  
Cohort Studies ◽  
Observational Studies ◽  
Real Life ◽  
Case Control ◽  
Sample Size Determination ◽  
Size Determination ◽  
Cross Sectional ◽  
Life Conditions ◽  
Study Designs

This chapter on observational studies provides an understanding of the main concepts in epidemiology, introduces common study designs, such as cross-sectional, case-control, and cohort studies, and outlines their importance for clinical research. The hallmark of epidemiological research is that it observes unexposed and exposed individuals under “real-life conditions” without intervening itself. The chapter emphasizes the important role of bias and confounding in interpreting results from such studies and explains how bias and confounding can be controlled. It furthermore discusses specific aspects of sample size determination that are relevant to observational studies. The chapter concludes with a brief review of the special nature of surgical research.

Introduction to epidemiological study designs

2020 ◽  
pp. 83-98
Author(s):  
Tamsin Ford ◽  
Jayati Das-Munshi ◽  
Martin Prince
Keyword(s):  
Mixed Methods ◽  
Data Collection ◽  
Cohort Studies ◽  
Epidemiological Study ◽  
Study Design ◽  
Case Control ◽  
Psychiatric Epidemiology ◽  
Case Control Studies ◽  
Cross Sectional ◽  
Study Designs

This chapter provides a brief overview for each of the main types of study design commonly used in psychiatric epidemiology. The chapter begins with a discussion of the importance of study design. This is followed by a section on classifying study design, including descriptive studies, ecological studies, cross-sectional surveys, cohort studies, case–control studies, intervention studies, and qualitative and mixed methods studies. The chapter concludes with a description of the basic steps which should be observed in the conduct of studies employing quantitative methodologies (including cross-sectional, cohort, and case–control studies), as well as discussing interviews/assessments, and data collection and processing.

scholarly journals Associations among housing accessibility, housing-related control beliefs and independence in activities of daily living: a cross-sectional study among younger old in Sweden

2019 ◽  
Vol 35 (3) ◽  
pp. 867-877 ◽  
Author(s):  
Giedre Gefenaite ◽  
Jonas Björk ◽  
Steven M. Schmidt ◽  
Björn Slaug ◽  
Susanne Iwarsson
Keyword(s):  
Activities Of Daily Living ◽  
Daily Living ◽  
Cross Sectional Study ◽  
Control Beliefs ◽  
National Study ◽  
Sectional Study ◽  
Cross Sectional ◽  
Mediating Role ◽  
Study Designs

AbstractThere is some evidence that housing accessibility, external housing-related control beliefs (HCB) and activities of daily living (ADL) are associated in complex ways; however, these pathways have not been explored in younger old. The aim was to assess the role of external HCB in the relationship between housing accessibility and ADL by applying moderation and mediation models. This was a cross-sectional study involving 366 community-living 67–70 years old participants from the Skåne part of the Swedish National Study of Aging and Care. We assessed moderation by including an interaction term in a logistic regression analysis (significant if p value < 0.05). We assessed mediation with a series of regression analyses with effect size measures expressed as proportion mediated and its 95% confidence interval (CI). In the absence of statistically significant interaction there was no support for external HCB as a moderator. There was evidence for partial mediation as external HCB was associated with ADL when controlled for housing accessibility, while housing accessibility remained associated with independence in ADL when adjusted for external HCB. The proportion mediated was 6% (95% CI 1; 14). While the results did not support external HCB as a moderator, external HCB mediated the association between housing accessibility and ADL. These results were different from previous findings suggesting that external HCB plays a marginally significant moderating and mediating role among very old. Such differences call for further studies that would allow further exploration and validation of the findings at different stages of the ageing process, preferably utilizing longitudinal study designs.

scholarly journals The possible role of arsenic and gene-arsenic interactions in susceptibility to breast cancer: a systematic review

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Roxana Moslehi ◽  
Cristy Stagnar ◽  
Sneha Srinivasan ◽  
Pawel Radziszowski ◽  
David O. Carpenter
Keyword(s):  
Breast Cancer ◽  
Systematic Review ◽  
Breast Cancer Risk ◽  
Cancer Risk ◽  
Epidemiologic Studies ◽  
Population Exposure ◽  
Case Control Studies ◽  
Cross Sectional

Abstract The roles of many environmental contaminants in increasing breast cancer risk remain controversial. Arsenic (As) is a major global environmental contaminant and carcinogen. We conducted a systematic review of the role of As and gene-arsenic interactions in susceptibility to breast cancer. Following a systematic literature search using well-defined inclusion/exclusion criteria, a total of 15 epidemiologic studies (two meta-analyses, three systematic reviews, three cohort studies, two case-control studies, and five cross-sectional studies) were reviewed. In addition, several animal, in vitro, in vivo, and in silico (i.e., computer modeling) studies provided mechanistic insights into the association between As and breast cancer. Our review suggests a possible overall main effect of As on breast cancer risk. The evidence for an effect of gene-As interactions on breast cancer risk is strong. Studies that measured levels of As metabolites among participants and/or evaluated interactions between As exposure and genetic or epigenetic factors generally reported positive associations with breast cancer risk. Our analysis of the Comparative Toxicogenomics and the Ingenuity Pathway Analysis Databases provided further evidence for As-gene interactions and their effects on breast cancer-related biologic pathways. Our findings provide potential leads for future epidemiologic studies of As-associated cancer risks and interventions to reduce population exposure.

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