Ovid Technologies Field Guide

Cochrane Central Register of Controlled Trials (CCTR)

The Evidence Based Medicine Reviews Collection

Scope

Evidence Based Medicine Reviews Collection

A patient asks a clinician, "Does vitamin C prevent the common cold? Are there effective therapies to treat a cold once you have one?" Although these questions are common, they are not always easy to answer. Medical knowledge is advancing rapidly, and the literature that reports new findings is expanding by almost half a million articles every year.

In the past, a clinician might seek answers to these questions within a textbook. But textbooks are updated infrequently, only every 3-5 years. And a new, definitive study might be published in today's medical journals, but not appear in the most recent textbooks.

The clinician might call an infectious disease specialist. But specialists are very busy, and may not have time to answer such questions.

The clinician might perform a traditional search in a medical database, such as MEDLINE. Unfortunately, a search using the MeSH term "common cold" yields over 1,400 articles written in the last 30 years. Finding a relevant article might take as long as 30 minutes or more.

But today, with Ovid's Evidence-Based Medicine Reviews (EBMR), answering clinical questions is a whole lot easier. Using Ovid's MEDLINE, a clinician can enter the term "common cold," select the EBM Reviews limit, and in seconds, a small number of high-quality articles appear that discuss prevention and treatment of the common cold.

Some of the articles retrieved have met rigorous inclusion criteria by the international Cochrane Collaboration, and then have been used as the basis for a systematic topic review. Clicking on the Topic Review link retrieves the Cochrane Review "Vitamin C for the Common Cold" which analyzes and synthesizes over 30 of the best clinical trials on the subject.

Other articles in the result set have been the subject of an evidence-based article review by the editorial staff of Best Evidence (a joint project of the American College of Physicians and BMJ Publishing Group) or by the National Health Services (NHS) Centre for Reviews and Dissemination at the University of York, England. Clicking on the Article Review link retrieves the enhanced abstract of the article together with commentary about the article's relevance to clinical practice.

So, the result from using Ovid's EBMR: the most comprehensive answer in less than a minute. EBMR helps clinicians to find the best answer to clinical questions in the least amount of time.

CCTR contains over 300,000 bibliographic references to controlled trials in health care. Cochrane groups and other organizations contribute their specialized registers; and these registers—together with references to clinical trials identified in MEDLINE and EMBASE—form the CCTR database. Contributors to the Cochrane Collaboration follow quality control standards to ensure that only reports of definite randomized controlled trials or controlled clinical trials are included.

Although many reports of trials are included in MEDLINE, others are not easily identified as randomized controlled trials; and as such, researchers may overlook them in the search for relevant studies for systematic reviews. CCTR records are identified through a combination of handsearching and database searching that include all those indexed as controlled trials in MEDLINE. Studies have shown that a MEDLINE search alone cannot be relied upon to identify all possible reports of controlled trials and suggest that a combination of handsearching and MEDLINE searching is most effective. This dual approach is the current practice of the Cochrane Collaboration, assuring you of the definitive quality of the CCTR database.

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General Information

Producer
	The Cochrane Collaboration Home Page: http://www.cochrane.org
Segments
	CCTR
	This database does not support Ovid's AutoAlerts. If you want to create a reusable search strategy, save the search as a Permanent Saved Search instead. See the Ovid Web Gateway User Manual for details about permanent saved searches. Saved search information also appears in the Ovid Web Gateway Help System.
All Fields Display/Print Fields
	Abstracts (AB)	Institution (IN)	Study Design (SD)
	Accession Number (AN)	ISSN (IS)	Study Name (SN)
	Author (AU)	Keywords (KW)	Source (SO)
	Cochrane Group Name (GC)	Local Mesages (LM)	Title (TI)
	Edition (EY)	MeSH Headings (SH)	Update Flag (UF)
	Editor (ED)	Original Title (OT)
	External Accession Number (EN)	Publication Type (PT)
Default Fields for Display/Print Fields
	Abstracts (AB)	Institution (IN)	Study Design (SD)
	Accession Number (AN)	ISSN (IS)	Study Name (SN)
	Author (AU)	Keywords (KW)	Source (SO)
	Cochrane Group Name (GC)	MeSH Headings (SH)	Title (TI)
	Editor (ED)	Original Title (OT)	Update Flag (UF)
	External Accession Number (EN)	Publication Type (PT)
Elements of the Source (SO) Field
	Conference Date (CD)	Issue/Part (IP)	Publisher (PB)
	Conference Location (CL)	Journal Name (JN)	Volume (VO)
	Edition (EY)	Page (PG)	Year of Publication (YR)

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Searching the CCTR Fields

The following list is sorted alphabetical by field alias. Click a field name to see the description and search information.

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The following list is sorted alphabetically by the two-letter label, and includes the relevant alias, at least one example for all searchable CCTR fields, and a description of the field.

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Advanced Searching

You can use special words and symbols to combine search terms and refine a search. For efficient searching, use the most appropriate operator from the list below to combine search terms. For more information on these and other searching techniques, including command line syntax searching, refer to the Ovid Gateway Help.

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CCTR Limits

• Abstracts: A limit to Abstracts restricts retrieval to documents that include abstracts.
• Cochrane Group: Selecting this CCTR limit restricts results to those documents submitted by a particular Cochrane group.
• Embase Records: Select this limit to restrict your retrieval to EMBASE records.
• Latest Update: A limit to Latest Update retrieves only those records that were added to CCTR with the most recent update.
• Medline Records: Select this limit to restrict your results to MEDLINE records.
• Publication Type: Select this CCTR limit to restrict your results to a particular type of publication, such as case report, letter or clinical trial.
• Publication Year: A limit to Publication Year restricts retrieval to documents that were published in the year range that you choose.

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CCTR Tools

• Tree
• Permuted Index
• Subheadings

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Changing to this Database from Another Database

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CCTR Producer Copyright Information

The materials contained herein are proprietary to the publishers and/or individual copyright holders and may only be used by authorized users of the subscribing institutions for internal or personal research. Authorized users may (i) print data obtained from searches and make limited copies of such printed search results, (ii) download data obtained from searches and (iii) retransmit search results electronically or otherwise to a limited number of authorized users at the same institution. Authorized users are precluded from: (i) copying, duplication, redistribution, retransmission, publication, transfer or commercial or other exploitation of the databases or the contents thereof, except as permitted herein or pursuant to user guidelines of the individual copyright holders, (ii) preparation of derivative works or incorporation of the databases or contents thereof in any other work or system; (iii) downloading of the contents in their entirety or lengthy sequence. Authorized users are referred to the individual copyright holder and/or to the copyright holder's usage guidelines within this database for additional restrictions which may be imposed by the copyright holder.

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Field Guide Updated April 4, 2006

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