Correspondence
Abstracts in high profile journals often fail to report harm
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* Corresponding author: Enrique Bernal-Delgado ebernal.iacs@aragon.es
1 Health Services Research Unit, Institute for Health Sciences in Aragon, Gómez Laguna Av. 25, 50009 Zaragoza, Spain
2 Center for Healthcare Research and Reform, Dartmouth Institute for Health Policy and Clinical Practice Lebanon, 03766 NH, USA
BMC Medical Research Methodology 2008, 8:14 doi:10.1186/1471-2288-8-14
Published: 27 March 2008Abstract
Background
To describe how frequently harm is reported in the abstract of high impact factor medical journals.
Methods
Design and population: We carried out a blinded structured review of a random sample of 363 Randomised Controlled Trials (RCTs) carried out on human beings, and published in high impact factor medical journals in 2003. Main endpoint: 1) Proportion of articles reporting harm in the abstract; and 2) Proportion of articles that reported harm in the abstract when harm was reported in the main body of the article. Analysis: Corrected Prevalence Ratio (cPR) and its exact confidence interval were calculated. Non-conditional logistic regression was used.
Results
363 articles and 407 possible comparisons were studied. Overall, harm was reported in 135 abstracts [37.2% (CI95%:32.2 to 42.4)]. Harm was reported in the main text of 243 articles [66.9% (CI95%: 61.8 to 71.8)] and was statistically significant in 54 articles [14.9% (CI95%: 11.4 to 19.0)]. Among the 243 articles that mentioned harm in the text, 130 articles [53.5% (CI95% 47.0 to 59.9)] reported harm in the abstract; a figure that rose to 75.9% (CI95%: 62.4 to 86.5) when the harm reported in the text was statistically significant. Harm in the abstract was more likely to be reported when statistically significant harm was reported in the main body of the article [cPR = 1.70 (CI95% 1.47 to 1.92)] and when drug companies (not public institutions) funded the RCTs [cPR = 1.29 (CI95% 1.03 to 1.67)].
Conclusion
Abstracts published in high impact factor medical journals underreport harm, even when harm is reported in the main body of the article.