An analysis of newspaper articles on medical research found that the media tends to focus on studies based on weak methodology and those that have little clinical importance.
The University of Florida study, published in the scientific journal PLOS ONE, compared characteristics of studies from 75 medically oriented journal articles that received coverage in the top five newspapers by circulation along with 75 such articles that appeared in the top five medical journals over a similar period of time.
Newspapers were significantly more likely to cover observational studies than the much more reliable randomized controlled trials (17 percent vs 35 percent). They also favored studies with much smaller sample groups, a median of 1984 compared to 21,136 in the medical publications.
One example cited by the study's authors involves an observational study that found a theoretical link between statin drug use and cancer risk. The press published hundreds of articles that, according to the analysis, encouraged "readers to draw dubious causal conclusions from observational data." In other words, mainstream media over hyped the material and made it seem more significant than it actually was.
Around the same time, a study considered important in the scientific community was published in a prestigious medical journal describing a randomized controlled trial of a promising new drug for advanced breast cancer. Google News searches found only 77 articles about the breast cancer discovery, compared to 311 about the statin study.
In describing their findings, the media study's authors write, "While it may not be surprising that the media tends to select articles outside of the highest impact journals, in doing so, they preferentially choose articles lower in the hierarchy of research design, thus favoring studies of lesser scientific credibility."