The effect of non-pharmaceutical interventions on COVID-19 cases, deaths and demand for hospital services in the UK: a modelling study

Nicholas G Davies; Adam J Kucharski; Rosalind M Eggo; Amy Gimma; W. John Edmunds

We analysed a stochastic compartmental model stratified into 5-year age bands, with individuals classified according to current disease status ( Fig. 1 ) and transmission between groups based on UK social mixing patterns ( [11, 12] ; full details in Supplementary Information). After infection with SARS-CoV-2 in the model, susceptible individuals pass through a latent period before becoming infectious, either with a preclinical and then clinical infection, or with a subclinical infection, before recovery or isolation. We refer to those infections causing few or no symptoms as subclinical. We assume older individuals are more likely to show clinical symptoms [11] . The model tracks 66.4 million people aggregated to the 186 county-level administrative units in England, Wales, Scotland, and Northern Ireland. clinical cases in each age group that would require hospitalisation, which was 0.8% in the 20-29 age group and 62% in the over-80 age group ( Table S2 ) .