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. 2006 Dec 16;333(7581):1248.
doi: 10.1136/bmj.38985.564317.7C. Epub 2006 Oct 23.

Ratio measures in leading medical journals: structured review of accessibility of underlying absolute risks

Lisa M Schwartz  1 , Steven Woloshin, Evan L Dvorin, H Gilbert Welch
Affiliations

Ratio measures in leading medical journals: structured review of accessibility of underlying absolute risks

Lisa M Schwartz et al. BMJ. .

Abstract

Objective: To examine the accessibility of absolute risk in articles reporting ratio measures in leading medical journals.

Design: Structured review of abstracts presenting ratio measures.

Setting: Articles published between 1 June 2003 and 1 May 2004 in Annals of Internal Medicine, BMJ, Journal of the American Medical Association, Journal of the National Cancer Institute, Lancet, and New England Journal of Medicine.

Participants: 222 articles based on study designs in which absolute risks were directly calculable (61 randomised trials, 161 cohort studies).

Main outcome measure: Accessibility of the absolute risks underlying the first ratio measure in the abstract.

Results: 68% of articles (150/222) failed to report the underlying absolute risks for the first ratio measure in the abstract (range 55-81% across the journals). Among these articles, about half did report the underlying absolute risks elsewhere in the article (text, table, or figure) but half did not report them anywhere. Absolute risks were more likely to be reported in the abstract for randomised trials compared with cohort studies (62% v 21%; relative risk 3.0, 95% confidence interval 2.1 to 4.2) and for studies reporting crude compared with adjusted ratio measures (62% v 21%; relative risk 3.0, 2.1 to 4.3).

Conclusion: Absolute risks are often not easily accessible in articles reporting ratio measures and sometimes are missing altogether-this lack of accessibility can easily exaggerate readers' perceptions of benefit or harm.

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Conflict of interest statement

Competing interests: None declared.

Figures

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Fig 1 Proportion of articles where absolute risks for first ratio measure were not reported in the abstract
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Fig 2 Suggested approaches to improve communication of ratio measures
See this image and copyright information in PMC

References

    1. Yueh B, Feinstein AR. Abstruse comparisons: the problems of numerical contrasts of two groups. J Clin Epidemiol 1999;52:13-8. - PubMed
    1. Forrow L, Taylor WC, Arnold RM. Absolutely relative: how research results are summarized can affect treatment decisions. Am J Med 1992;92:121-4. - PubMed
    1. Naylor C, Chen E, Strauss B. Measured enthusiasm: does the method of reporting trial results alter perceptions of therapeutic effectiveness? Ann Intern Med 1992;117:916-21. - PubMed
    1. Fahey T, Griffith S, Peters T. Evidence based purchasing: understanding results of clinical trials and systematic reviews. BMJ 1995;311:1056-9. - PMC - PubMed
    1. Hux JE, Naylor CD. Communicating the benefits of chronic preventive therapy: does the format of efficacy data determine patient's acceptance of treatment? Med Decis Making 1995;15:152-7. - PubMed

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