Letter to the Editor: “Characteristic CT findings distinguishing 2019 novel coronavirus disease (COVID-19) from influenza pneumonia”
by Angela Moreno, Sergio Valencia (sevava92@gmail.com)
Characteristic CT findings distinguishing 2019 novel coronavirus disease (COVID-19) from influenza pneumoniaDear Editor,
We read with interest the article entitled “Characteristic CT findings distinguishing 2019 novel coronavirus disease (COVID-19) from influenza pneumonia” by Wang et all (1). The authors show the difference between COVID-19 diseases vs Influenza disease on chest CT. Nevertheless, we are worried about the sample size, especially in the COVID-19 group.
Throughout the article, the authors never present an inclusion and exclusion criteria. We do not know how these patients were selected and why there are so few patients in the COVID -19 group. Also, patients with influenza were not tested for COVID-19. For this reason, co-infection cannot be excluded. We believe that this problem can be a selection bias that can alter the veracity of the findings (2). Especially when COVID-19 disease has a wide presentation pattern and depends on patients’ comorbidities and disease stage, in some cases these characteristics can imitate and influenza pneumonia (3).
We respectfully ask to the authors their selection criteria; why there are so few patients? And how do they think that these possible biases affect their results?