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EBM guide (page 1)

page 1

The process of EBM | Types of EBM searches | Types of clinical questions

Search in EBM reviews using the Cochrane Database of Systematic Reviews | What is a systematic review? | What is EBM Reviews: the Cochrane Database of Systematic Reviews? | What is the Cochrane collaboration? | Divide the question into concepts | Search and results

Search in Medline (OVID) and then apply the EBM reviews limit | What is an EBN reviews limit? | The Cochrane databases | Search and results

page 2

What are Clinical Queries limits? | Search strategies used for OVID Medline Clinical Queries limitss | Search and results

What are PubMed clinical queries? | Search and results

Evaluation


The process of EBM

   information needs
   question formulation   
   literature searching
   critical appraisal
   application

There are a number of steps involed in the process of evidence based medicine. This guide will focus only on literature searching aspects of EBM as covered in the Library run workshops.

Types of EBM searches

There are a number of literature search types detailed here. These are not placed in any specific heirarchical order nor do they all need to be performed when conducting a literature search once the information has been found.

  1. Search in EBM reviews using the Cochrane Database of Systematic Reviews
  2. Search in Medline (OVID) and then apply the EBM reviews limit
  3. Search in Medline (OVID) and then apply an EBM filter from the saved search list
  4. Search in PubMed clinical queries

Types of clinical questions

There are 4 bacis types of clinical questions used in the EBM process:

  • Therapy or treatment questions
  • Prognosis questions
  • Aetiology or causation questions
  • Diagnosis questions

(The most frequently asked questions are about diagnosis and treatment)

An example of a search question could be: is glucosamine sulphate an effective agent in the short-term treatment of osteoarthritis?

We will use this example question (taken from the GMP EBM course) to demonstrate the 4 searches listed above.

The first search uses the Cochrane Database of Systematic Reviews.


Search in EBM reviews using the Cochrane Database of Systematic Reviews

What is a systematic review?

A review of a clearly formulated question that uses systematic and explicit methods to identify, select and critically appraise relevant research, and to collect and analyse data from the studies that are included in the review. Statistical methods (meta-analysis) may or may not be used to analyse and summarise the results of the included studies.

What is EBM Reviews: the Cochrane Database of Systematic Reviews?

A database of full-text of the regularly updated systematic reviews of the effects of healthcare prepared by the Cochrane Collaboration. The database consists of Complete Reviews and Protocols. Protocols are not reviews but include information on the backgound, objectives and methods of reviews in preparation. Topics covered include clinical medical information and subject reviews.

What is the Cochrane collaboration

The Cochrane Collaboration consists of groups of experts in over 40 clinical specialties who authoritatively review hundreds of studies on topics in their specialty; select those that meet strict EBM criteria; perform "meta-analyses" when possible on all the included studies; and then write detailed, structured reviews of the topic and the findings. These reviews allow clinicians to get fast, "bottom line" answers to their most commonly-asked questions, based on a comprehensive and expert analysis of the available medical literature.1

Divide the question into concepts

The question to be used in the database should be divided into the concepts:

  • Patient population/disease
  • Intervention (diagnostic or treatment)
  • Comparisons
  • Outcome

Into the example given above this translates as:

Patient population/disease ­> osteoarthritis
AND
Intervention ­> glucosamine sulphate

There was no Comparator or Outcome in this example.

Search and results

Open the database EBM Reviews: the Cochrane Database of Systematic Reviews
In the search field enter the term glucosamine and click on perform search.
The result is 4 articles (this number will change in time as more records are added to the database).
In the search field enter the term osteoarthritis and click on perform search.
The result is 77 articles (this number will also change in time as more records are added to the database).
Combine the first search with the second by typing 1 and 2 in the search field and click on perform search.
The result is 2 articles. Both deal with glucosamine and its effects on osteoarthritis. To view the full text of the article, click on topic review.


Search in Medline (OVID) and then apply the EBM reviews limit

What is an EBN reviews limit?

When you perform a search on OVID Medline the results can be filtered by ticking the EBM reviews box on the OVID Medline page. This performs a search on your results to include only those articles that have met the strict, quality criteria of ACP Journal Club, DARE, or the Cochrane Database of Systematic Reviews.

The Cochrane databases

The University subscribes to 4 different Cochrane databases. These include:

EBM Reviews: the Cochrane Database of Systematic Reviews
A database of full-text of the regularly updated systematic reviews of the effects of healthcare prepared by the Cochrane Collaboration. The database consists of Complete Reviews and Protocols. Protocols are not reviews but include information on the backgound, objectives and methods of reviews in preparation. Topics covered include clinical medical information and subject reviews.

EBM Reviews: ACP Journal Club
Consists of two EBM journals the ACP Journal Club, from the American College of Physicians, and Evidence Based Medicine, a joint publication with the BMJ Group. Subject areas are clinical medical information and article reviews.

EBM Reviews: Database of Abstracts of Reviews of Effectiveness
Contains critical assessments of systematic reviews from a variety of medical journals. Topics covered include diagnosis, prevention, rehabilitation, screening, and treatment.

Note: The Cochrane Database of Systematic Reviews should be searched separately. Not all Cochrane systematic reviews can be located through Medline. The EBMR Limit will only give access Cochrane systematic reviews that are also located in Medline.

Search and results

Open the database Medline (OVID version)
In the search field enter the term glucosamine and click on perform search.
Click in the explode button and then continue.
Click continue on the next screen to include all subheadings.
The result is around 9000 articles (this number will continually change in time as more records are added to the database).
In the search field enter the term osteoarthritis and click on perform search.
Click in the explode button next to the top subject heading and then continue.
Click continue on the next screen to include all subheadings.
The result is around 9000 articles (this number will continually change in time as more records are added to the database).
The result is 22000 articles (this number will also change in time as more records are added to the database).
Combine the first search with the second by typing 1 and 2 in the search field and click on perform search.
The result is around 200 articles.
Click in the EBM reviews button underneath the search field and then perform search.
The result will be under 10 articles. Full text is available either through OVID full text or topic reviews.

Go to page 2 for the rest of the guide.