Fig. 3

The determining factors in diagnosing COVID-19 based on test results, presenting symptoms, clinical observations and imaging. Each Triage Point denotes a separate time point in which the results of the testing would be determined. Following the results, the patients were cohorted accordingly into Red, Pink, Yellow, Green, or Hyper Green zones. Zones donated as a different colour, i.e. Blue, Yellow/Amber, indicate a difference in cohort terminology across NHS trusts. Common blood tests results for viral and respiratory infection used as a proxy for COVID-19 diagnosis during the first wave were: a full blood count showing leukocytopoenia, lymphocytopoenia and neutropoenia [16]. Thrombocytopoenia was also sometimes used by clinicians as an indicator of COVID due to it not being a common finding in infection