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.

scholarly journals A probability model for evaluating the bias and precision of influenza vaccine effectiveness estimates from case-control studies

2014 ◽  
Vol 143 (7) ◽  
pp. 1417-1426 ◽  
Author(s):  
M. HABER ◽  
Q. AN ◽  
I. M. FOPPA ◽  
D. K. SHAY ◽  
J. M. FERDINANDS ◽  
...  
Keyword(s):  
Influenza Vaccine ◽  
Medical Care ◽  
Randomized Clinical Trials ◽  
Probability Model ◽  
Control Design ◽  
Case Control ◽  
Vaccine Effectiveness ◽  
Case Control Studies ◽  
Respiratory Illnesses ◽  
Study Designs

SUMMARYAs influenza vaccination is now widely recommended, randomized clinical trials are no longer ethical in many populations. Therefore, observational studies on patients seeking medical care for acute respiratory illnesses (ARIs) are a popular option for estimating influenza vaccine effectiveness (VE). We developed a probability model for evaluating and comparing bias and precision of estimates of VE against symptomatic influenza from two commonly used case-control study designs: the test-negative design and the traditional case-control design. We show that when vaccination does not affect the probability of developing non-influenza ARI then VE estimates from test-negative design studies are unbiased even if vaccinees and non-vaccinees have different probabilities of seeking medical care against ARI, as long as the ratio of these probabilities is the same for illnesses resulting from influenza and non-influenza infections. Our numerical results suggest that in general, estimates from the test-negative design have smaller bias compared to estimates from the traditional case-control design as long as the probability of non-influenza ARI is similar among vaccinated and unvaccinated individuals. We did not find consistent differences between the standard errors of the estimates from the two study designs.

scholarly journals Role of Matching in Case-Control Studies of Antimicrobial Resistance

2009 ◽  
Vol 30 (5) ◽  
pp. 480-483 ◽  
Author(s):  
Elizabeth Cerceo ◽  
Ebbing Lautenbach ◽  
Darren R. Linkin ◽  
Warren B. Bilker ◽  
Ingi Lee
Keyword(s):  
Antimicrobial Resistance ◽  
Case Control ◽  
Case Control Studies ◽  
Matched Case

Of 57 case-control studies of antimicrobial resistance, matching was used in 23 (40%). Matched variables differed substantially across studies. Of these 23 matched case-control studies, 12 (52%) justified the use of matching, and 9 (39%) noted the strengths or limitations of this approach. Analysis that accounted for matching was performed in only 52% of the case-control studies.

scholarly journals Association between Risk Factors for Vascular Dementia and Adiponectin

2014 ◽  
Vol 2014 ◽  
pp. 1-13 ◽  
Author(s):  
Juhyun Song ◽  
Won Taek Lee ◽  
Kyung Ah Park ◽  
Jong Eun Lee
Keyword(s):  
Risk Factors ◽  
Cardiovascular Disease ◽  
Signal Transduction ◽  
Vascular Dementia ◽  
Case Control ◽  
Case Control Studies ◽  
Insulin Signal Transduction ◽  
Increased Risk ◽  
The Brain

Vascular dementia is caused by various factors, including increased age, diabetes, hypertension, atherosclerosis, and stroke. Adiponectin is an adipokine secreted by adipose tissue. Adiponectin is widely known as a regulating factor related to cardiovascular disease and diabetes. Adiponectin plasma levels decrease with age. Decreased adiponectin increases the risk of cardiovascular disease and diabetes. Adiponectin improves hypertension and atherosclerosis by acting as a vasodilator and antiatherogenic factor. Moreover, adiponectin is involved in cognitive dysfunction via modulation of insulin signal transduction in the brain. Case-control studies demonstrate the association between low adiponectin and increased risk of stroke, hypertension, and diabetes. This review summarizes the recent findings on the association between risk factors for vascular dementia and adiponectin. To emphasize this relationship, we will discuss the importance of research regarding the role of adiponectin in vascular dementia.

Effect of Exposure to Cats and Dogs on the Risk of Asthma and Allergic Rhinitis: A Systematic Review and Meta-analysis

2020 ◽  
Vol 34 (5) ◽  
pp. 703-714
Author(s):  
Xiaoping Gao ◽  
Mei Yin ◽  
Pei Yang ◽  
Xia Li ◽  
Lingling Di ◽  
...  
Keyword(s):  
Systematic Review ◽  
Allergic Rhinitis ◽  
Cohort Studies ◽  
Meta Analysis ◽  
Pooled Analysis ◽  
Protective Role ◽  
Case Control ◽  
Favorable Effect ◽  
Case Control Studies

Background Controversies persist regarding whether exposure to cat or dog increases the risk of asthma and allergic rhinitis. Objective This meta-analysis aimed to assess the associations between exposure to cats or dogs and the development of asthma and allergic rhinitis. Methods A systematic review was performed to identify case-control and cohort studies before May 2019, evaluating the association between exposure to cats and dogs and the risk of asthma and rhinitis. The risk of bias was assessed using the Newcastle–Ottawa Scale. The odds ratios (ORs) and risk ratios (RRs) were pooled for case-control and cohort studies, respectively. Subgroup analyses were performed on prespecified study-level characteristics. Results The meta-analysis of 34 cohort studies showed a protective role of exposure to cats [RR: 0.88, 95% confidence interval (CI): 0.77–0.99] or dogs (RR: 0.85, 95% CI: 0.73–0.97) in the development of asthma. The subgroup analysis of birth cohort (RR: 0.74, 95% CI: 0.56–0.93) and children population (RR: 0.83, 95% CI: 0.70–0.96) also suggested a favorable role of exposure to dogs in the development of asthma. Pooled evidence from 13 case-control studies indicated no significant impact of cats (OR: 1.66, 95% CI: 0.39–2.94) and dogs (OR: 1.22, 95% CI: 0.92–1.52) on the development of asthma. A pooled analysis of five cohort studies showed a favorable effect of exposure to cats (RR: 0.60, 95% CI: 0.33–0.86) or dogs (RR: 0.68, 95% CI 0.44–0.90) on the development of allergic rhinitis. Conclusion The findings indicated a protective effect of exposure to cats and dogs, especially ownership, on the development of asthma and allergic rhinitis.

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.

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.

scholarly journals Do Case-Control Studies Always Estimate Odds Ratios?

2020 ◽  
Author(s):  
Jeremy A Labrecque ◽  
Myriam M G Hunink ◽  
M Arfan Ikram ◽  
M Kamran Ikram
Keyword(s):  
Incidence Rate ◽  
Case Control Study ◽  
Case Control ◽  
Small Sample ◽  
Incidence Density ◽  
Odds Ratios ◽  
Case Control Studies ◽  
Rate Ratios ◽  
Study Designs ◽  
Control Study

Abstract Case-control studies are an important part of the epidemiologic literature, yet confusion remains about how to interpret estimates from different case-control study designs. We demonstrate that not all case-control study designs estimate odds ratios. On the contrary, case-control studies in the literature often report odds ratios as their main parameter even when using designs that do not estimate odds ratios. Only studies using specific case-control designs should report odds ratios, whereas the case-cohort and incidence-density sampled case-control studies must report risk ratio and incidence rate ratios, respectively. This also applies to case-control studies conducted in open cohorts, which often estimate incidence rate ratios. We also demonstrate the misinterpretation of case-control study estimates in a small sample of highly cited case-control studies in general epidemiologic and medical journals. We therefore suggest that greater care be taken when considering which parameter is to be reported from a case-control study.

scholarly journals Sustainability in complex environments: making sense of the Katrina lawsuits

2014 ◽  
Vol 11 (3) ◽  
pp. 162-169 ◽  
Author(s):  
Catalin Ratiu ◽  
Beverlee B. Anderson
Keyword(s):  
General Public ◽  
Skewed Distribution ◽  
Convenience Sample ◽  
Content Type ◽  
Making Sense ◽  
Course Of Action ◽  
Innovative Methodology ◽  
Sustainability Initiatives ◽  
Social Environmental ◽  
The Many

Purpose – The meaning of sustainability continues to be debated by scholars and professionals alike. But how do individuals, who are expected to contribute to implementing sustainability actions, perceive this important concept? The purpose of this paper is to explore how individuals relate to the multidimensionality of sustainability. Design/methodology/approach – The paper uses a qualitative design to learn how individuals understand and prioritise the various dimensions of sustainability. Respondents were asked to react in essay form to a narrative that weaves social, environmental, economic and legal issues and offer a recommended course of action. Findings – The findings are mixed, showing that sustainability is yet to mature as a concept in the minds of the general public. Encouragingly, the paper finds evidence that most respondents are aware of the primary dimensions of sustainability. Research limitations/implications – The research is limited by the convenience sample used, which may offer a skewed distribution. Practical implications – While defining sustainability conceptually continues to preoccupy scholars and policy makers, educating the general public on these advancements should also be prioritised, given the high reliance on individuals to implement the many sustainability initiatives and innovations in existence. Originality/value – The study uses an innovative methodology to learn how individuals perceive a very complex topic.

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