0

The full content of Annals is available to subscribers

Subscribe/Learn More  >
Academia and the Profession |

Evaluation of the Quality of Prognosis Studies in Systematic Reviews

Jill A. Hayden, DC; Pierre Côté, DC, PhD; and Claire Bombardier, MD
[+] Article and Author Information

From Institute for Work and Health, University of Toronto, and Mount Sinai Hospital, Toronto, Ontario, Canada.


Acknowledgments: The authors thank Drs. Doug Altman and Greta Ridley for valuable comments on earlier versions of this manuscript, Drs. Sheilah Hogg-Johnson and George Tomlinson for comments and discussion on the design and analysis, Evelyne Michaels for her assistance with editing and useful comments on an earlier draft of this manuscript, and Jeremy Dacombe and Quenby Mahood for assistance with literature retrieval.

Grant Support: This project was partially funded by a research grant from the Ontario Chiropractic Association and Ontario Ministry of Health and Long Term Care Special Chiropractic Research Fund. Dr. Hayden is supported by a Postdoctoral Fellowship Award from the Canadian Institutes of Health Research and Canadian Chiropractic Research Foundation. Dr. Côté is supported by a New Investigator Award from the Canadian Institutes for Health Research and by the Institute for Work and Health and the Workplace Safety and Insurance Board of Ontario. Dr. Bombardier holds a Canada Research Chair in Knowledge Transfer for Musculoskeletal Care.

Potential Financial Conflicts of Interest: None disclosed.

Requests for Single Reprints: Jill A. Hayden, DC, Institute for Work and Health, 481 University Avenue, Suite 800, 8th Floor, Toronto, Ontario M5G 2E9, Canada; e-mail, jhayden@iwh.on.ca.

Current Author Addresses: Drs. Hayden and Côté: Institute for Work and Health, 481 University Avenue, Suite 800, 8th Floor, Toronto, Ontario M5G 2E9, Canada.

Dr. Bombardier: Toronto General Hospital, Eaton North Wing, 6th Floor, Room 231A, 200 Elizabeth Street, Toronto, Ontario M5G 2C4, Canada.


Ann Intern Med. 2006;144(6):427-437. doi:10.7326/0003-4819-144-6-200603210-00010
Text Size: A A A

Background: To provide valid assessments of answers to prognostic questions, systematic reviews must appraise the quality of the available evidence. However, no standard quality assessment method is currently available.

Purpose: To appraise how authors assess the quality of individual studies in systematic reviews about prognosis and to propose recommendations for these quality assessments.

Data Sources: English-language publications listed in MEDLINE from 1966 to October 2005 and review of cited references.

Study Selection: 163 systematic reviews about prognosis that included assessments of the quality of studies.

Data Extraction: A total of 882 distinct quality items were extracted from the assessments that were reported in the various reviews. Using an iterative process, 2 independent reviewers grouped the items into 25 domains. The authors then specifically identified domains necessary to assess potential biases of studies and evaluated how often those domains had been addressed in each review.

Data Synthesis: Fourteen of the domains addressed 6 sources of bias related to study participation, study attrition, measurement of prognostic factors, measurement of and controlling for confounding variables, measurement of outcomes, and analysis approaches. Reviews assessed a median of 2 of the 6 potential biases; only 2 (1%) included criteria aimed at appraising all potential sources of bias. Few reviews adequately assessed the impact of confounding (12%), although more than half (59%) appraised the methods used to measure the prognostic factors of interest.

Limitations: Reviews may have been missed by the search or misclassified because of incomplete reporting. Validity and reliability testing of the authors' recommendations are required.

Conclusions: Quality appraisal, a necessary step in systematic reviews, is incomplete in most reviews of prognosis studies. Adequate quality assessment should include judgments about 6 areas of potential study biases. Authors should incorporate these quality assessments into their synthesis of evidence about prognosis.

Figures

Grahic Jump Location
Figure 1.
Flow diagram of inclusion and exclusion criteria of systematic reviews.

The primary reason for exclusion is noted. *Includes 4 articles not available for full-article screening.

Grahic Jump Location
Grahic Jump Location
Figure 2.
Number of systematic reviews of prognosis studies identified over time.

The electronic search included 1996 to October 2005.

Grahic Jump Location

Tables

References

Letters

NOTE:
Citing articles are presented as examples only. In non-demo SCM6 implementation, integration with CrossRef’s "Cited By" API will populate this tab (http://www.crossref.org/citedby.html).

Comments

Submit a Comment
Submit a Comment

Summary for Patients

Clinical Slide Sets

Terms of Use

The In the Clinic® slide sets are owned and copyrighted by the American College of Physicians (ACP). All text, graphics, trademarks, and other intellectual property incorporated into the slide sets remain the sole and exclusive property of the ACP. The slide sets may be used only by the person who downloads or purchases them and only for the purpose of presenting them during not-for-profit educational activities. Users may incorporate the entire slide set or selected individual slides into their own teaching presentations but may not alter the content of the slides in any way or remove the ACP copyright notice. Users may make print copies for use as hand-outs for the audience the user is personally addressing but may not otherwise reproduce or distribute the slides by any means or media, including but not limited to sending them as e-mail attachments, posting them on Internet or Intranet sites, publishing them in meeting proceedings, or making them available for sale or distribution in any unauthorized form, without the express written permission of the ACP. Unauthorized use of the In the Clinic slide sets will constitute copyright infringement.

Toolkit

Buy Now

to gain full access to the content and tools.

Want to Subscribe?

Learn more about subscription options

Advertisement
Related Articles
Topic Collections
PubMed Articles

Buy Now

to gain full access to the content and tools.

Want to Subscribe?

Learn more about subscription options

Forgot your password?
Enter your username and email address. We'll send you a reminder to the email address on record.
(Required)
(Required)