Workshop on OSLER - OVID Search: Links to Electronic Resources

by Christian Veillette M.D., B.Sc(Hon)

This workshop will utilize the OSLER Medline Search facilities supplied by the Canadian Medical Association as a free service exclusively for CMA Members.

The objective of this workshop is to provide a practical approach to using OVID to perform a Medline Search. Several excellent in-depth descriptions of OVID Search Software and Interfaces are available on-line:

• OVID Quick Reference Card
• OVID User Guide

What is OVID?

OVID is a search interface, much like PubMed, for bibliographic databases such as Medline. OVID uses extremely powerful search strategies and software to provide a rich, interlinked knowledge environment designed to deliver authoritative answers to questions quickly and easily. It has several features that are not available with PubMed and Internet Grateful Medicine. Another advantage is that there is a CMA librarian who will help you out with your searches if you are having difficulty.

Features of OVID: Overview

You may be asking - Why use OVID when there is PubMed and Internet Grateful Medicine? Read the editorial Questions keep coming about CMA's OSLER service

Clinical Scenario: During this workshop we will consider the management of a middle age woman with a wrist fracture, specifically treatment by external fixation and/or Kapandji intrafocal pinning. We will be searching the literature using the facilities available at OSLER OVID

Click on the above OSLER banner to open a new window that will take you to the CMA OSLER website. You can switch between the workshop and the OSLER website to work through aspects of the workshop.

Note:

• Workshop comments will be indicated in RED
• Workshop instructions will be indicated in GREEN
• screen captures, and icons on the current page are not functional and are for descriptive purposes only
• various links from this web page open up a new browser window, when you are finished with the contents in the new browser window simply close the window and return to this web page.
 
Once you have registered and obtained a password for OSLER,
 Click

The OSLER Entry Page allows you several options. Choose Search OVID NOW.

You will be asked which version you would like to use. Choose OVID Release 4.1.0. (After May 17, 2000 this will automatically take place)

Next select the database you would like to search.

Choose 1966 - June 2000 Week 5 for the broadest coverage of the topic.

OSLER Advanced Search: OSLER automatically places users in Ovid's advanced mode, which provides several features essential to complex literature searching.

On the Advanced Search page you will find the above graphical display. For a description of the various icons across the top of the page visit the OSLER Quick Reference Guide

In the Enter Key Word or Phrase dialog box enter the keyword wrist fracture. Make sure that the Map Term to Subject Heading has a checkmark beside it.

Your Keyword is mapped to a set of Subject Headings which you can now select from. If you are uncertain about whether a Subject Heading accurately describes your Keyword you can select the Subject Heading and a Directory Tree will be displayed that shows the relationship of the Subject Heading to more broad and more specific categories. This helps you to define your search strategy.

Learn more about "Mapping your way through Medline"

You can select multiple Subject Headings to increase the documents searched but this also has the drawback of decreasing the specificity of the search.

One of the advantages of OVID is that you can enter a number of Keywords separately, view the results and then use the icon to improve the selectivity of your search. You can initially start out with a brainstorming session for various search keywords that you think might find the most relevant articles to answer your specific question.

Select Colles' Fracture and the Explode Feature (includes all more specific categories below this Subject Heading). Click

Place a checkmark within the Include all Subheadings box. Click

You will see the following Search History appear.

#	Search History	Results	Display
1	exp Colles' Fracture/	500

The initial search term wrist fracture matched to Colles' Fracture and results in 500 Citations. The relevance of the articles to our management question is variable. The first 10 citations are listed below the main search history display. Now try different variations of searching with the keyword wrist fracture such as:

• wrist fracture without Map term to Subject Heading (corresponds to Search #2)
• wrist fracture with Map term to Subject Heading but choose "wrist fracture.mp" Search as Keyword (corresponds to Search #3)
• wrist fracture with Map term to Subject Heading but select BOTH Colles' Fracture and "wrist fracture.mp" Search as Keyword (corresponds to Search #4)

#	Search History	Results	Display
1	exp Colles' Fracture/	500
2	wrist fracture.mp. [mp=title, abstract, registry number word, mesh subject heading]	62
3	wrist fracture.mp.	62
4	wrist fracture.mp. or exp Colles' Fracture/	558

You can see that by selecting both wrist fracture.mp AND Colles' Fracture (exploded) you obtain a larger number of results. Also make note that searching without the Map to Subject Heading (#2)  is the same as selecting search as Keyword within the mapping to a subject heading screen (#3).

Note: You can customize the display of the citations, by clicking on the  tab and choosing the features you desire.

Select the  tab and set the display number of  citations to 500 or 1000. Within the Customize Display page you can also select brief citation or to include the abstract.

Within the first 20 citations, our search with the Keyword wrist fractures mapped to Colles' fractures (search #1) produces a number of moderately relevant articles but none specific to our question. We could continue searching through all 500 citations like this but that is not efficient. Lets use another search term to improve the scope of our search results.

The main skill to develop in performing a literature search is to use the most appropriate search terms or search concepts. There is no single way to perform a search, and different methods often lead to finding the same articles, BUT there are ways to improve your efficiency which we will explore.

Return to the main search page and perform the following searches in succession as we did previously. Select appropriate Subject Headings, remember to Explode the Subject Heading, select search as Keyword and then Select All Subheadings.

Keyword: (Perform searches for each term separately)

• Distal radius fracture
• External fixation
• Kapandji
• Pinning

You will find that when you attempt to search using Kapandji as the Keyword it maps to a number of Subject Headings that have been listed previously. In this scenario it is best to choose the "Kapandji.mp" search as keyword function alone. This also applies to the keyword pinning.

The number of citations for each search term:

#	Search History	Results	Display
1	exp Colles' Fracture/	500
2	wrist fracture.mp. [mp=title, abstract, registry number word, mesh subject heading]	62
3	wrist fracture.mp.	62
4	wrist fracture.mp. or exp Colles' Fracture/	558
5	exp Radius Fractures/ or distal radius fracture.mp.	3509
6	external fixation.mp. or exp External Fixators/	3012
7	Kapandji.mp.	95
8	pinning.mp.	606
9	pinning.mp. or exp Radius Fractures/	4023

Theoretically, the articles we are attempting to find to answer our clinical question should be within the results of these search strategies. You could search through all the results from search #5 and most likely you would find the article to help you answer your question but this is extremely impractical and inefficient.

Now we will use the icon to further limit our search to a manageable, more specific number of citations. By looking at your Search History (which really is a brain storming session of search strategies) you can intelligently combine the various Keyword & Subject Headings (also known as concepts) by entering the two search #'s in the enter keyword box combined with "and" (no quotations marks)

If you do this for the various combinations (choose the largest number of citations -least specific-, and use the more specific searches to cone down the citations list) then you will end up with a manageable list of citations to search through. You are combining your keyword searches (concepts) to come up with the perfect search strategy to answer your clinical question. It takes a little practice.

For example, in the Enter Keyword box type:  5 and 6 then click .

Combine search terms in a logical manner that you think will lead to a combination of concepts that will find relevant articles. You can perform combinations quickly and browse the results and further modify your next  combination or you may even decide that another keyword may be more appropriate.

#	Search History	Results	Display
1	exp Colles' Fracture/	500
2	wrist fracture.mp. [mp=title, abstract, registry number word, mesh subject heading]	62
3	wrist fracture.mp.	62
4	wrist fracture.mp. or exp Colles' Fracture/	558
5	exp Radius Fractures/ or distal radius fracture.mp.	3509
6	external fixation.mp. or exp External Fixators/	3012
7	Kapandji.mp.	95
8	pinning.mp.	606
9	pinning.mp. or exp Radius Fractures/	4023
10	5 and 6	298
11	5 and 7	50
12	5 and 8	80
13	4 and 6	61
14	4 and 7	9
15	4 and 8	13
16	10 and 7	5
17	10 and 8	11
18	4 and 6 and 8	2

Explanation of Search Strategies:

Combining search terms/concepts can be an extremely effective way of defining a specific subset of articles relevant to the clinical topic. You can view the results of the various combinations above to see the effectiveness of the strategies. Everyone has their limit as to the number of articles they are willing to wade through to find the article that answers their question. The most intuitive search combination is 5 and 6 and 8 OR 4 and 6 and 8. These combinations lead to 11 and 2 citations respectively.  (Note: Search #10 combines 5 and 6)

Clinical Scenario Revisited:

The bottom line from the articles comparing pinning with external fixation is that similar results with respect to eventual function, range of motion, and grip strength are obtained. Complications and complaints were fewer and the estimated costs of treatment were significantly less in the pinning group. More patients were satisfied with closed pinning than with external fixation.

 

Limit your search:

With OVID you can use the  icon quite effectively to select out clinical trials. Select . The Limit Search display page will appear. Now select the Search #  you would like to limit, in our case choose either #4 or #5. Next scroll down the page until you find the area that says Publication type. Choose Randomized Controlled Trial  and then select

You obtain 73 citations from limiting search #5 and 48 citations from limiting search #4. A relatively easily manageable number of citations to browse through. The articles previously identified by our previous search strategy using the combine icon are found in the results of each search.

Email Citations:

Now that you have found the type of information that you have been interested in. You may want to email it to yourself so you have a hard copy.

Select the Citations that are relevant and then use the Citation manager at the bottom of the page to send these to your email account.

Citation Manager: Display, Print, Save, or Email Citations

Citations	Fields	Citation Format	Action
Selected Citations All in this set (1-48) and/or Range:	Citation (Title,Author,Source) Citation + Abstract Citation + Abstract + Subject Headings Complete Reference	Ovid BRS/Tagged Reprint/Medlars Brief (Titles) Display Include Search History
Sort Keys
Primary: - Unique Identifier Authors Institution Title Source Year of Publication Language Country of Publication Publication Type Journal Subset Entry Month Ascending Descending Secondary: - Unique Identifier Authors Institution Title Source Year of Publication Language Country of Publication Publication Type Journal Subset Entry Month Ascending Descending

You now have a copy of your citations relevant to your question. Make sure you select Include Search History in the Citation Manager so that you have a description of your search strategy.

Carrying out this kind of search takes persistence, practice and continued refinement. Computerized systems are inherently dumb and not good at reading your mind. Your medical librarian is trained to do this for you and may be the best resource if the quality of your search is an important issue.

The CMA has a dedicated librarian to help you use the OSLER OVID efficiently and effectively. This is probably one of the biggest advantages of the search software. Unfortunately the CMA does not subscribe to some of the most useful aspects of OVID which are direct links to a variety of Journal Articles through Journals@OVID and the OVID Biomedical Collection. Many Universities have subscriptions to OVID that are available to students and faculty which utilize all of these powerful features of OVID Technology.

Other Features:

There are several other features of OVID that we have not utilized in this workshop. Take the time to explore the icons to help you locate specific references. The CMA has had an overwhelming response since it implemented the OSLER website and have plans to subscribe to the powerful full text features in the near future to further maximize your ability to integrate literature searches with direct access to relevant journal articles.

Bottom Line:

• OSLER provides a highly efficient, intuitive interface to search the Medline Database.
• The most difficult aspect of any literature search is defining the appropriate search strategy. This takes practice like anything else.
• Set up your initial search using Map to MeSH headings, search with individual concepts or search terms and later combine these to focus down on your specific question.
• Use the Limit icon to further limit the search results to a specific age group, type of publication, year range, or another one of the numerous variables available.
• A search strategy for answering a clinical question is very different than for an all encompassing literature search. Learn how to perform both efficiently and effectively.
• Become comfortable with a search interface and learn to utilize its power features to maximize your efficiency.