Bias in the COVID-19 era

Editor – We thank Kelly et al for an informative and useful article.¹ There is only a short mention of clinical biases, and I believe that this point needs further attention. Cognitive biases are omnipresent in medicine. They can affect reasoning and result in adverse events.² A few types of biases exist here. One was confirmation bias which is the analysis of information in a particular way to confirm and strengthen original suspicions or hypotheses. This was most probably in play on the patient's first presentation where the diagnosis of ‘mild COVID-19’ was entertained. There is also clear availability bias, this is an intrinsic human tendency where one assesses the likelihood of an event by how often other examples come to one's mind, thus creating mental shortcuts. Anchoring bias was also at play, this is where one settles on a diagnosis based on a few important features. It is difficult to know if affective bias was present, which is the tendency to convince oneself what one wants to be true. It is also easy to perform a retrospective analysis of any case such as this one and this is by no means a criticism of the initial treatment, but COVID-19 mimics are increasingly being described.³ Good clinical acumen and an understanding of cognitive biases (which are not taught at medical school and only come from continuous adult learning and reflective practice) will make sure that patients continue to receive good medical care.