One of the cornerstones of scientific research is the reproducibility of findings. Novel scientific observations need to be validated by subsequent studies in order to be considered robust. This has proven to be somewhat of a challenge for many biomedical research areas, including high impact studies in cancer research and stem cell research. The fact that an initial scientific finding of a research group cannot be confirmed by other researchers does not mean that the initial finding was wrong or that there was any foul play involved. The most likely explanation in biomedical research is that there is tremendous biological variability. Human subjects and patients examined in one research study may differ substantially from those in follow-up studies. Biological cell lines and tools used in basic science studies can vary widely, depending on so many details such as the medium in which cells are kept in a culture dish. The variability in findings is not a weakness of biomedical research, in fact it is a testimony to the complexity of biological systems. Therefore, initial findings need to always be treated with caution and presented with the inherent uncertainty. Once subsequent studies – often with larger sample sizes – confirm the initial observations, they are then viewed as being more robust and gradually become accepted by the wider scientific community.
Even though most scientists become aware of the scientific uncertainty associated with an initial observation as their career progresses, non-scientists may be puzzled by shifting scientific narratives. People often complain that “scientists cannot make up their minds” – citing examples of newspaper reports such as those which state drinking coffee may be harmful only to be subsequently contradicted by reports which laud the beneficial health effects of coffee drinking. Accurately communicating scientific findings as well as the inherent uncertainty of such initial findings is a hallmark of critical science journalism.
A group of researchers led by Dr. Estelle Dumas-Mallet at the University of Bordeaux recently studied the extent of uncertainty communicated to the public by newspapers when reporting initial medical research findings in their recently published paper “Scientific Uncertainty in the Press: How Newspapers Describe Initial Biomedical Findings“. Dumas-Mallet and her colleagues examined 426 English-language newspaper articles published between 1988 and 2009 which described 40 initial biomedical research studies. They focused on scientific studies in which a new risk factor such as smoking or old age had been newly associated with a disease such as schizophrenia, autism, Alzheimer’s disease or breast cancer (total of 12 diseases). The researchers only included scientific studies which had subsequently been re-evaluated by follow-up research studies and found that less than one third of the scientific studies had been confirmed by subsequent research. Dumas-Mallet and her colleagues were therefore interested in whether the newspaper articles, which were published shortly after the release of the initial research paper, adequately conveyed the uncertainty surrounding the initial findings and thus adequately preparing their readers for subsequent research that may confirm or invalidate the initial work.
The University of Bordeaux researchers specifically examined whether headlines of the newspaper articles were “hyped” or “factual”, whether they mentioned whether or not this was an initial study and clearly indicated they need for replication or validation by subsequent studies. Roughly 35% of the headlines were “hyped”. One example of a “hyped” headline was “Magic key to breast cancer fight” instead of using a more factual headline such as “Scientists pinpoint genes that raise your breast cancer risk“. Dumas-Mallet and her colleagues found that even though 57% of the newspaper articles mentioned that these medical research studies were initial findings, only 21% of newspaper articles included explicit “replication statements” such as “Tests on larger populations of adults must be performed” or “More work is needed to confirm the findings”.
The researchers next examined the key characteristics of the newspaper articles which were more likely to convey the uncertainty or preliminary nature of the initial scientific findings. Newspaper articles with “hyped” headlines were less likely to mention the need for replicating and validating the results in subsequent studies. On the other hand, newspaper articles which included a direct quote from one of the research study authors were three times more likely to include a replication statement. In fact, approximately half of all the replication statements mentioned in the newspaper articles were found in author quotes, suggesting that many scientists who conducted the research readily emphasize the preliminary nature of their work. Another interesting finding was the gradual shift over time in conveying scientific uncertainty. “Hyped” headlines were rare before 2000 (only 15%) and become more frequent during the 2000s (43%). On the other hand, replication statements were more common before 2000 (35%) than after 2000 (16%). This suggests that there was a trend towards conveying less uncertainty after 2000, which is surprising because debate about scientific replicability in the biomedical research community seems to have become much more widespread in the past decade.
As in all scientific studies, we need to be aware of the analysis performed by Dumas-Mallet and her colleagues. They focused on analyzing a very narrow area of biomedical research – newly identified risk factors for selected diseases. It remains to be seen whether other areas of biomedical research such as treatment of diseases or basic science discoveries of new molecular pathways are also reported with “hyped” headlines and without replication statements. In other words – this research on “replication statements” in newspaper articles also needs to be replicated. It is not clear that the worrisome trend of over-selling robustness of initial research findings after the year 2000 still persists since the work by Dumas-Mallet and colleagues stopped analyzing studies published after 2009. One would hope that the recent discussions about replicability issues in science among scientists would reverse this trend. Even though the findings of the University of Bordeaux researchers need to be replicated by others, science journalists and readers of newspapers can glean some important information from this study: One needs to be wary of “hyped” headlines and it can be very useful to interview authors of scientific studies when reporting about new research, especially asking them about the limitations of their work. “Hyped” newspaper headlines and an exaggerated sense of certainty in initial scientific findings may erode the long-term trust of the public in scientific research, especially if subsequent studies fail to replicate the initial results. Critical and comprehensive reporting of biomedical research studies – including their limitations and uncertainty – by science journalists is therefore a very important service to society which contributes to science literacy and science-based decision making.
Dumas-Mallet, E., Smith, A., Boraud, T., & Gonon, F. (2018). Scientific Uncertainty in the Press: How Newspapers Describe Initial Biomedical Findings. Science Communication, 40(1), 124-141.
Note: An earlier version of this article was first published on the 3Quarksdaily blog.