Conclusion
Our approach is flexible enough to create reference cohorts, which will allow estimation of COVID-19 severity using known characteristics and outcomes. As more data on European cases are published, the system can be applied to cases with a more comparable background. First comparisons expose the high rate of patients requiring ventilation over prolonged time periods, thus hospital resources may be in higher demand of ventilation supply than usual. In fact, Liu et al. suggests that early non-invasive mechanical ventilation can promote positive outcomes [9]. This can only be implemented if hospitals prepare for high utilisation of ventilation and intensive care resources. Although fatalities occur mostly among elderly people with chronic comorbidities, serious disease progressions do also occur among younger, healthy patients and more often than would be expected from the experience during influenza epidemics.