Everyone likes a positive result, and “positive” scientific papers are more frequently seen in the literature than those which have “negative” or unclear findings. An interesting essay in the prestigious journal ‘Science’ reflects on “negative results” and what their non-publication means for the scientific process. Strikingly it says, “In fields from clinical medicine to psychology…the literature is filled with papers that present results as stronger than they actually are—and rarely report negative outcomes”. A different, but related, issue concerns cherry-picking data or spinning the conclusions, to make the results seem more powerful than they actually are. All of which has the potential to ‘skew’ the scientific literature and muddy the waters for investigators, funders and, ultimately, patients.
In illnesses, such as ME/CFS, where scientific interest is low and the evidence-base (the total number of scientific papers) comparatively small, skewing towards positive results could be particularly problematic. Shockingly, there have been far fewer clinical trials in ME/CFS (417 to date) than in comparable chronic illnesses like multiple sclerosis (3234) or rheumatoid arthritis (7101), so there is at least the potential for an over-emphasis on apparently positive findings to have skewed the literature and, possibly, treatment options. Of course, it’s hard to be definitive – since we cannot know the number of “negative” trials locked in filing cabinets or the occasions when raw data has been over-spun. However, the author’s suggestion of changing the culture to allow “embracing and sharing null findings without regret or shame” seems sound and sensible.
Reference: The Power of Negative Thinking. Couzin-Frankel J. Science, 2013 Oct 4; 342(6154): 68-69.