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Searching for the Evidence Class: Searching for the Evidence - Class

Video Training

The companion guide, Searching for Evidence Based Information, provides detailed video tutorials that provide background information and demonstrate searching skills included in this class.

Objectives and Definitions

CLASS OBJECTIVES
Recognize options for limiting literature search retrieval to valid and reliable research studies appropriate for clinical decision making;
Search The Cochrane Library, Dynamed, FIRSTConsult, ACP Journal Club, and other clinical information support resources;
Limit an Ovid or EMBASE search to evidence based limits;
Search PubMed MEDLINE using Clinical Queries and learn to set up NCBI filters for EBHC.    
 
What is evidence-based practice?
the conscientious, explicit, and judicious use of current best evidence in making decisions about the care of individual patients. --Sackett DL, et al. Evidence-based medicine: what it is and what it isn’t. BMJ 1996;312 (7023):71-72.  
 
“Evidence-based medicine (EBM) is the integration of best research evidence with clinical expertise and patient values.” --Guyatt G, et al. Evidence-Based Medicine working Group. Evidence-based medicine. A new approach to teaching the practice of medicine. JAMA 1992; 268: 2420-5.

Why is retrieving “current best evidence difficult?

  • Glut of published literature
  • Quality of literature
  • Poor searching skills


Formulating a Question

Formulating a Clinical Question
The well-built clinical question: a key to evidence-based decisions. Richardson WS, Wilson MC, Nishikawa J, Hayward RS. ACP J Club. 1995 Nov-Dec; 123(3): A12-3.

 

Example Clinical Scenarios:

Diagnosis: How to select a diagnostic test or how to interpret the results of a particular test.

  • In patients with suspected depression what is the accuracy of a two-question case-finding instrument for depression compared with six previously validated instruments?
  • In patients with no symptoms, which screening test is most accurate for diagnosing breast cancer?

 

Therapy: Which treatment is the most effective, or what is an effective treatment given a particular condition.

  • In children with colds, are zinc lozenges safe and effective for relief of cold symptoms?
  • In patients with acute bronchitis, do antibiotics reduce sputum production, cough or days off work?

 

Harm or Etiology: Are there harmful effects of a particular treatment, or how can these harmful effects be avoided.

  • What are the risks of treating asthma patients with beta-adrenergic agonists?
  • In women taking oral contraceptives, is there an association between their use and cardiovascular disease?

 

Prognosis: What is the patient's likely course of disease, or how to screen for or reduce risk.

  • In a healthy woman who has suffered a miscarriage, what is the normal grief process and are any factors associated with longer than normal grieving?
  • What are the risk factors for developing diabetes mellitus type II in adolescent males?

Define the clinical problem using the PICO components described above:

 

 

Now describe your own clinical scenario:

 

Create a PICO for the scenario –

P –

 

 

I –

 

 

C –

 

 

O –


 

 

Types of Evidence Based Resources

Finding the best evidence in the literature


Online tools and databases where you find evidence-based resources can be divided into three categories:

1. Those that do most of the work for you

2. Those that do some of the work for you

3. Those where you do most of the work

But even when most of the work is done for you you will still need to use your critical judgment!


Level of Evidence

Type 1

Type 1

·    The Cochrane Library includes the following files:

 

       1.   Cochrane Database of Systematic Reviews (Cochrane Reviews) rigorous, full-text reviews done by

Cochrane Review Groups with explicitly stated objectives and eligibility criteria, a comprehensive literature search, comparison of studies to criteria, justification of exclusions plus occasional updates

- Every Cochrane Systematic Review must have a standardized title including: Intervention / for a specific Problem / in a Patient Population (when appropriate)

- Every review goes through the following stages:

Title Review > Protocol Review > Protocol Publication > Review Development > Review Publication > Update > And sometimes, Withdraw

 

2.   Database of Abstracts of Reviews of Effectiveness (DARE or Other Reviews) - systematic reviews published in journals and other, non-Cochrane sources, with quality assessed structured abstracts, produced by the Centre for Reviews and Dissemination (CRD) at the University of York, UK.

 

3.   Cochrane Central Register of Controlled Trials (Clinical Trials) journal citations of randomized trials, just under half are from MEDLINE, the remainder are from the European medical index EMBASE, as well as other published and unpublished sources, including Cochrane Groups Specialized Registers.

4.   Cochrane Database of Methodology Reviews (Methods Reviews) full-text systematic reviews on research methodological studies

5.   Cochrane Methodology Register (Methods Studies) - citations on publications on how to conduct controlled trials and systematic reviews

6.  Health Technology Assessment Database (Technology Assessments) structured abstracts of studies on the medical, social, ethical and economic implications of health care interventions. Produced by the CRD.

   

7.   NHS Economic Evaluation Database (Economic Evaluations) structured abstracts of critically appraised economic evaluations of health care interventions, produced by the CRD.

 

8.   About the Cochrane Collaboration (Cochrane Groups) description of Cochrane Review Groups, Centres, etc.

 - Updated quarterly.

Individual subscription available  

 

Type 2

·       ACP JournalClub   Includes the reviews from ACP Journal Club (1991-2004) and Evidence-Based Medicine (December 1995-1999), which has merged with ACP Journal Club and is updated quarterly.  Search PubMed for "ACP journal club"[Jour] and add a topic, as in "ACP journal club"[Jour] AND CABG  Individual subscription  available.

·       Dynamed is a clinical reference tool including more than 3,000 topics created by physicians for health care professionals for use primarily at the 'point-of-care'. DynaMed is updated daily> and monitors the content of over> 500> medical journals and systematic evidence review databases. Levels of recommendation are graded A-C; levels of evidence are rated 1-3.

·       FIRSTConsult  is an evidence-based clinical information resource. Recommendations for practice are graded A (high quality systematic reviews or RCTs), B (non-randomized trials> and other types of experimental designs), or C (consensus or expert opinion) by trained editors. Free “PocketConsult”  smartphone version is available from the library.

·      Natural Medicines Comprehensive Database is an evidence- based source> of information on the ingredients, interactions, effectiveness, and use of brand name natural products and substances. Products are graded effective to ineffective using evidence based reviews of the literature. Smartphone  version

·        Nursing Consult is an evidence based resource designed especially for clinical nurses. A seven level grading scheme is used in the Evidence Based Nursing section of the resource.

·        UpToDate now offers evidence grading. 1 or 2 indicates the strength of the recommendation, A/B/C indicates the grade for the quality of the evidence used.  

A1 might mean - a systematic review> where all included studies are RCTs with good follow up studying outcomes of clinical importance.

B2 might mean - a good quality non-random study that meets only one additional criteria – for example, the outcome is of clinical importance.

C3 might mean - consensus or other expert based information – which meets no criteria for study design.

Type 3

Type 3

·    Ovid MEDLINE and CINAHL “Clinical Queries” limit feature (Attachment 1)

·    PubMed MEDLINE “Clinical Queries” feature (Attachment 2) - Click on the Clinical Queries link under the PubMed Tools heading on the main page

Use My NCBI filters for evidence based medicine (Attachment 4)

·    EMBASE Evidence Based” limits (Attachment 2)

Tips for retrieving EBM literature in Ovid MEDLINE, PubMed, and EMBASE:

· Use Clinical Trial publication types (pt) to limit your MEDLINE search to articles about actual clinical trials and to automatically explode all 7 clinical trial terms (below).

Clinical Trial.pt. (1991)
Clinical Trial, Phase I.pt. (1993)
Clinical Trial, Phase II.pt. (1993)
Clinical Trial, Phase III.pt. (1993)
Clinical Trial, Phase IV.pt. (1993)
Controlled Clinical Trial.pt. (1995)

Randomized Controlled Trial.pt. (1991)

 

Clinical Trials, the medical subject heading, retrieves articles on how to conduct clinical trials.

· Dont limit your search to Review (pt). Reserve the Review limit for “quick ‘n dirty searching.  -Ann Intern Med 1999;131:947-951.

· Core Clinical Journals, also known as AIM (Abridged Index Medicus), limits your search to 120 clinical journals commonly found in hospital libraries. Use this limit for "quick ‘n dirty searching only, and not EBHC searches.

MORE RESOURCES

Class handout describing some of the evidence-based resources available to Health Sciences Library users. Attachments to this handout are also available.

Searching for the Evidence