Non-reporting of negative findings
Non-reporting of negative findings
What is this about?
Non-reporting of negative findings is a phenomenon that happens in science, when there is a bigger chance of publishing when you have a positive research result (a statistically significant finding of effect).  One of the consequences of this phenomenon is publication bias. 
- Duyx B, Urlings MJE, Swaen GMH, Bouter LM, Zeegers MP. Scientific citations favor positive results: a systematic review and meta-analysis. J Clin Epidemiol. 2017;88:92-101.
- Song F, Parekh S, Hooper L, Loke YK, Ryder J, Sutton AJ, et al. Dissemination and publication of research findings: an updated review of related biases. Health Technol Assess. 2010;14(8):1-193.
Why is this important?
Research in biomedical sciences reveals that positive results have a higher chance of being published. Because of that, negative results (for example, the lack of effect of some therapy) might be unavailable to the scientific community. Consequently, when other researchers conduct systematic reviews and meta-analysis, the results are distorted in favor of the positive finding. Clinical trials with negative results, and those with reported serious side effects, often don’t get published, which is dangerous, unfair to participants, and a waste of resources.  Getting negative results in a costly project and after a lot of hard work can be very demotivating, disappointing and can negatively impact young researchers’ careers. Some supervisors may not be happy to publish negative results, and in that way add to the climate of positive-publications-only.
- Brassington I. The ethics of reporting all the results of clinical trials. British Medical Bulletin. 2017;121(1):19-29.
For whom is this important?
What are the best practices?
If a study’s methodology is valid, it is important to publish all of the results, including negative ones. The International Committee of Medical Journal Editors stated that researchers should publish negative data in order to prevent publication bias and potential waste of time and money because of duplication. World Health Organization, in 2005, called for publication of previous non-reported negative findings. The Committee on Publication Ethics, in their guidelines, state that journals should not refuse to publish negative findings. Some journals are dedicated to publication of null results only, such as the Journal of Negative Results, in the field of ecology and evolutionary biology. BioMed Central’s Journal of Negative results in BioMedicine ceased to publish in 2017.
In order to assess publication bias when conducting a meta-analysis, researchers use a funnel plot. A funnel-plot is a type of scatter-plot, in which both treatment effect and study precision are shown. If the data is not symmetrical, there is a high chance of either publication bias or small-study effect.  This is especially important when doing a meta-analysis of clinical trials, as such results often end up being used as the strongest evidence in making of clinical practice guidelines. 
- Weintraub PG. The Importance of Publishing Negative Results: J Insect Sci. 2016 Oct 23;16(1):109. doi: 10.1093/jisesa/iew092. eCollection 2016.
- Kicinski M. How does under-reporting of negative and inconclusive results affect the false-positive rate in meta-analysis? A simulation study. BMJ Open. 2014;4(8):e004831.
The Embassy Editorial team, Iris Lechner, Natalie Evans, Hannele Pitkänen contributed to this theme. Latest contribution was Oct 28, 2020