Basic prediction methodology for covid-19: estimation and sensitivity considerations

Tom Britton

We end by predicting the final fraction infected, and the total number of case fatalities, at the end of the outbreak. This is possible from simply knowing the reproduction number, as described in the method section. For instance, if R 0 = 3 the final size equation gives τ = 94%. If preventive measures with magnitude ρ = 1/3 are put in place during the early stage and kept all trough the outbreak, then the predicted final size instead equals τ E = 78% In the more likely case of a heterogeneous community the fractions should be deflated by about 20%. Similarly, the predicted total number of case fatalities is N f τ = and N f τ E respectively. Since communities typically are heterogeneous better estimates would be to deflate these numbers by about 20%.