Effects 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, Thibaut Jombart, Kathleen O’Reilly, Akira Endo, Joel Hellewell, Emily Nightingale, Billy J. Quilty, Christopher I Jarvis, Timothy Russell, Petra Klepac, Nikos I Bosse, Sebastian Funk, Sam Abbott, Graham F. Medley, Hamish Gibbs, Carl A. B. Pearson, Stefan Flasche, Mark Jit, Samuel Clifford, Kiesha Prem, Charlie Diamond, Jon C. Emery, Arminder Deol, Simon R. Procter, Kevin van Zandvoort, Yueqian Fiona Sun, James D Munday, Alicia Roselló, Megan Auzenbergs, Gwen Knight, Rein M G J Houben, Yang Liu
Abstract
Background Non-pharmaceutical interventions have been implemented to reduce transmission of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in the UK. Projecting the size of an unmitigated epidemic and the potential effect of different control measures has been crucial to support evidence-based policy making during the early stages of the epidemic. This study assesses the potential impact of different control measures for mitigating the burden of COVID-19 in the UK. Methods We used a stochastic age-structured transmission model to explore a range of intervention scenarios, tracking 664 million people aggregated to 186 county-level administrative units in England, Wales, Scotland, and Northern Ireland. The four base interventions modelled were school closures, physical distancing, shielding of people aged 70 years or older, and self-isolation of symptomatic cases. We also modelled the combination of these interventions, as well as a programme of intensive interventions with phased lockdown-type restrictions that substantially limited contacts outside of the home for repeated periods. We simulated different triggers for the introduction of interventions, and estimated the impact of varying adherence to interventions across counties. For each scenario, we projected estimated new cases over time, patients requiring inpatient and critical care (ie, admission to the intensive care units [ICU]) treatment, and deaths, and compared the effect of each intervention on the basic reproduction number, R 0 .