Objective: To identify the source (press releases or news) of distortions, exaggerations, or changes to the main conclusions drawn from research that could potentially influence a reader’s health related behavior.
Design: Retrospective quantitative content analysis.
Setting: Journal articles, press releases, and related news, with accompanying simulations.
Sample: Press releases (n = 462) on biomedical and health related science issued by 20 leading UK universities in 2011, alongside their associated peer reviewed research papers and news stories (n = 668).
Main Outcome Measures: Advice to readers to change behavior, causal statements drawn from correlational research, and inference to humans from animal research that went beyond those in the associated peer reviewed papers.
Results: 40% (95% confidence interval 33%−46%) of the press releases contained exaggerated advice, 33% (26%−40%) contained exaggerated causal claims, and 36% (28%−46%) contained exaggerated inference (humans from animal research).
When press releases contained such exaggeration, 58% (95% confidence interval 48%−68%), 81% (70%−93%), and 86% (77%−95%) of news stories, respectively, contained similar exaggeration, compared with exaggeration rates of 17% (10%−24%), 18% (9%−27%), and 10% (0%−19%) in news when the press releases were not exaggerated. Odds ratios for each category of analysis were 6.5 (95% confidence interval: 3.5−12), 20 (7.6−51), and 56 (15–211). At the same time, there was little evidence that exaggeration in press releases increased the uptake of news.
Conclusions: Exaggeration in news is strongly associated with exaggeration in press releases. Improving the accuracy of academic press releases could represent a key opportunity for reducing misleading health related news.