Research Guides (LibGuides): Evidence-Based Practice: Evidence, Study Designs, and Clinical Tools

Haynes Pyramid of the Hierarchy of Evidence

Townsend W; Donovan K; Ginier E; MacEachern M; Mani N. "Integrated "5S" Levels of Organization of Evidence Pyramid". September 2015. (http://hdl.handle.net/2027.42/138965). CC BY 4.0 https://creativecommons.org/licenses/by/4.0/. Adapted from: Haynes RB. Of studies, syntheses, synopses, summaries and systems: the “5S" evolution of services for evidence-based health care decisions. ACP J Club. 2006 Nov-Dec;145(3):A8-9.

In order to make an evidence-based decision in the clinical setting, an awareness of the levels of evidence is essential. Here you'll find the Haynes pyramid which guides you through the reliability of evidence found in the medical literature.

Definitions of Study Types

Meta-analysis: A systematic review that uses quantitative methods to synthesize and summarize the results.

Systematic Review: The application of strategies that limit bias in the assembly, critical appraisal, and synthesis of all relevant studies on a specific topic. SRs focus on peer-reviewed publications about a specific health problem and use rigorous, standardized methods for selecting and assessing articles.

Randomized Controlled Trial (RCT): An experiment in which subjects in a population are randomly sorted into two or more groups to receive or not receive an experimental preventative or therapeutic procedure or treatment. The two groups' results are then assessed to determine the effectiveness of the treatment.

Controlled Clinical Trial: These experiments are similar to RCTs except that the methods of selecting the groups are non-randomized. These types of studies are more likely to suffer from bias than RCTs.

Observational Study: A type of study in which the researchers compare people who receive an intervention to those who do not. The researchers are not involved in the selection of the population nor the original intervention, but instead compare the records of the patients who had been treated with the intervention to those who had not been treated. Examples of observational studies are cohort and case-control studies.

Case Series: A group or series of case reports involving patients who were given similar treatment. There is no comparison group for case series studies.

(Adapted from CEBM and Dahlgren Memorial Library)

Best Study Designs by Type of Clinical Question

Type of Question	Most Appropriate Study Design
Diagnosis	Independent, blind comparison to a gold standard
Therapy	1. RCT 2. Cohort Studies 3. Case Control 4. Case Series
Prognosis	1. Cohort Studies 2. Case Control 3. Case Series
Harm	1. Cohort Studies 2. Case Control 3. Case Series
Prevention	1. RCT 2. Cohort Studies 3. Case Control 4. Case Series

Swanberg SM, Mi M, Engwall K. An integrated, case-based approach to teaching medical students how to locate the best available evidence for
clinical care. MedEdPORTAL. 2017;13:10531. https://doi.org/10.15766/mep_2374-8265.10531

Summaries

UpToDate Online This link opens in a new window
NOTE: After signing in via this link, users may create a personal login to access content anywhere, but they must re-verify the personal account every 90 days. UpToDate is a comprehensive, evidence-based clinical information on the topics of Internal Medicine, Obstetrics and Gynecology, Family Medicine, and Pediatrics.
5 Minute Clinical Consult This link opens in a new window
5 Minute ClinicalConsult is a fully integrated online resource to help guide primary care professionals and clinical students in daily decision support, used to obtain the most likely diagnosis, treatment, and management for thousands of diseases.

Guideline Central
Access to thousands of clinical practice guidelines for medical professionals.
National Guideline Clearinghouse
Evidence-based clinical guidelines, research, and tools provided by the Agency for Healthcare Research and Quality (AHRQ)
ACCESSSS
ACCESSSS provides "one-stop" access to pre-appraised evidence to address this key question: what is the current best evidence available to support clinical decisions?
Trip Database
Trip is a clinical search engine designed to allow users to quickly and easily find and use high-quality research evidence to support their practice and/or care.

Synopses

ACP Journal Club
ISBN: 10568751
Evidence-Based Medicine
ISBN: 1356-5524
Evidence-Based Mental Health
ISBN: 1468-960X
Evidence-Based Nursing
ISBN: 14689618

DARE
The Database of Abstracts of Reviews of Effects (DARE): CRD researchers systematically search the world literature to identify and describe systematic reviews, appraise their quality and highlight strengths and weaknesses.

Syntheses

Cochrane Library (Wiley) This link opens in a new window
The Cochrane Library (ISSN 1465-1858) is a collection of six databases that contain different types of high-quality, independent evidence to inform healthcare decision-making, and a seventh database that provides information about Cochrane groups.

Evidence Alerts
EvidenceAlerts is a continuously updated repository of current best evidence from research to support evidence-based clinical decisions. EvidenceAlerts does not cover basic science, and is providing clinically relevant new evidence to practicing physicians more than a comprehensive literature database for researchers.
PubMed Clinical Queries
Limit your PubMed search to clinical filters

PubMed (MEDLINE) This link opens in a new window
Limit your search to systematic reviews

Studies

PubMed (MEDLINE) This link opens in a new window
Article citations, often with abstracts, from more than 4,000 national and international periodicals, books and dissertations in medicine, nursing, dentistry, and related topics; online equivalent to Index Medicus.
PsycINFO + Medline This link opens in a new window
Set up to search both PsycINFO and Medline simultaneously.
Cochrane Library (Wiley) This link opens in a new window
The Cochrane Library (ISSN 1465-1858) is a collection of six databases that contain different types of high-quality, independent evidence to inform healthcare decision-making, and a seventh database that provides information about Cochrane groups.

PubMed Clinical Queries
Limit your PubMed search to Clinical Study Categories
ClinicalTrials.gov
ClinicalTrials.gov is a database of privately and publicly funded clinical studies conducted around the world.
WHO International Clinical Trials Registry Platform
The Clinical Trials Search Portal provides access to a central database containing the trial registration data sets provided by the registries.

Background Resources

AccessMedicine This link opens in a new window
AccessMedicine is a resource that features medical content, plus multimedia, self-assessment, algorithms, case studies, and more.
AccessPharmacy This link opens in a new window
AccessPharmacy is an online resource that allows users to explore pharmacy references, search curriculum topics, and research
ClinicalKey This link opens in a new window
ClinicalKey is a database designed for medical professionals. It provides full-text articles from Elsevier’s collection, as well as access to images, videos, and books.
UpToDate Online This link opens in a new window
NOTE: After signing in via this link, users may create a personal login to access content anywhere, but they must re-verify the personal account every 90 days. UpToDate is a comprehensive, evidence-based clinical information on the topics of Internal Medicine, Obstetrics and Gynecology, Family Medicine, and Pediatrics.

Integrated Clinical Tools

Micromedex Healthcare Series This link opens in a new window
Full text from the compilation of databases including Poisondex, Drugdex, Emerindex, Identidex, etc. covering drug information, drug therapy, and toxicology.

Evidence-Based Practice: Evidence, Study Designs, and Clinical Tools