In past editions of Critical Links we have covered marketing and hype made in the image of the scientific process, and the ultimate impact — positive or negative — on the conclusions we draw and how we react. There are examples of influence all around us, all the time. While tuned into the pandemic, we’re following news like we never have before.
In one example, there seems to be a mounting body of evidence to suggest that the respiratory route of transmission is the main culprit when it comes to COVID-19. If you look at a paper recently published in the Annals of Internal Medicine, you’ll see one of their key messages supports this idea: “Direct contact and fomite transmission are presumed but are likely only an unusual mode of transmission.” Based on this paper, whether it is your proclivity or not, you can probably empathize with someone who jumps to the conclusion that hand hygiene and other touch-based precautionary measures are futile. But, let’s take a closer look at the paper from a literature-navigation and information mastery perspective.
An initial word of caution is the category the article falls into: Review. (Note: This does not apply to Systematic Reviews.) Reviews, also known as narrative reviews, while often appearing to be of high scientific rigour (because of all the jargon) are actually a fairly low-level quality of evidence. That’s not necessarily damning, because they could purposefully or inadvertently come to the correct conclusion. But, because they do not need to include a systematic collection and assessment of all of the evidence, they may be missing some important contributing studies, and the risk of misleading is quite high. As such, if we want to draw conclusions, as readers we need to keep looking at higher-quality evidence and syntheses of studies, such as well-conducted systematic reviews, guidelines, etc., from authorities on the subject matter. These exist.
In the end, it may very well turn out that when it comes to COVID-19 transmission, respiratory is the main concern. If that’s the case, great — we know what to do next. But to hang your hat on one paper — one review article — is fraught with problems. If you’re going to ignore good hand hygiene and infection prevention measures just because you think you don’t have to worry about it so much for COVID-19, you’re going to be ignoring many other transmissible diseases (e.g., norovirus, adenovirus, etc.).
What needs to be mentioned is that a sick day is no longer just a sick day; it’s more like sick days. That’s because “It’s just a cold!” can no longer be presumed to be merely a cold. If you have a headache, technically, you should be getting tested for coronavirus. If you’re getting tested for coronavirus, you’re likely to be off work for a few days. This has big impacts on us as individuals and our society.
Bottom line: Maintain some hope that maybe we won’t have to worry as much as we have about non-respiratory transmission — the evidence is mounting. But, don’t forget there are many other good reasons to practice good hand hygiene, to clean surfaces regularly, and to do what we can within reason to protect ourselves and others.
Oh, and avoid conflating reviews with systematic reviews!