Misrepresentation of Randomized Controlled Trials in Press Releases and News Coverage: A Cohort Study

Background: Previous studies indicate that in published reports, trial results can be distorted by the use of spin (specific reporting strategies, intentional or unintentional, emphasizing the beneficial effect of the experimental treatment). We aimed to (1) evaluate the presence of spin in press releases and associated media coverage; and (2) evaluate whether findings of randomized controlled trials (RCTs) based on press releases and media coverage are misinterpreted. Methods and Findings: We systematically searched for all press releases indexed in the EurekAlert! database between December 2009 and March 2010. Of the 498 press releases retrieved and screened, we included press releases for all two-arm, parallel-group RCTs (n = 70). We obtained a copy of the scientific article to which the press release related and we systematically searched for related news items using Lexis Nexis. Spin, defined as specific reporting strategies (intentional or unintentional) emphasizing the beneficial effect of the experimental treatment, was identified in 28 (40%) scientific article abstract conclusions and in 33 (47%) press releases. From bivariate and multivariable analysis assessing the journal type, funding source, sample size, type of treatment (drug or other), results of the primary outcomes (all nonstatistically significant versus other), author of the press release, and the presence of spin in the abstract conclusion, the only factor associated, with spin in the press release was spin in the article abstract conclusions (relative risk [RR] 5.6, [95% CI 2.8-11.1], p,<0.001). Findings of RCTs based on press releases were overestimated for 19 (27%) reports. News items were identified for 41 RCTs; 21 (51%) were reported with spin, mainly the same type of spin as those identified in the press release and article abstract conclusion. Findings of RCTs based on the news item was overestimated for ten (24%) reports. Conclusion: Spin was identified in about half of press releases and media coverage. In multivariable analysis, the main factor associated with spin in press releases was the presence of spin in the article abstract conclusion. Please see later in the article for the Editors' Summary.