COVID-19 scenario modelling for the mitigation of capacity-dependent deaths in intensive care: computer simulation study

Richard M Wood; Christopher J McWilliams; Matthew J Thomas; Christopher P Bourdeaux; Christos Vasilakis

The copyright holder for this preprint . https://doi.org/10. 1101 In the absence of any intervention to reduce the basic reproduction rate (R0) through case isolation, home quarantine and social distancing (i.e. the No isolation strategy of Scenario 1), the estimated death toll is significantly higher than otherwise. Employing these measures reduces total deaths by an estimated 57% and cuts the peak daily deaths by more than two-thirds ceteris paribus (Scenario 2). Increasing capacity from 45 to 76 intensive care beds (Scenario 3) further reduces total deaths by 14%, with an effect starting to show on the number of subsequent days at maximum capacity (reducing from 68 to 62). This is brought down further (to 57 days) should capacity increases to 100 beds be possible (Scenario 4), which also brings down total deaths to under 2000. Reducing mean length of stay by onequarter appears to have a relatively small improvement to the total number of deaths (Scenario 5 c.f. Scenario 2), which is in part due to the right-skewed nature of the length of stay distribution (i.e. the number of longer-staying patients in the tail is unchanged since the shape of the distribution is presumed unaltered).