The effectiveness of non-pharmaceutical interventions in containing epidemics: a rapid review of the literature and quantitative assessment

Jane Cheatley; Sabine Vuik; Marion Devaux; Stefano Scarpetta; Mark Pearson; Francesca Colombo; Michele Cecchini

A rapid review of the literature was undertaken to identify salient NPIs used to combat influenza outbreaks and their associated effectiveness. Academic, peer-reviewed articles were sourced from major databases including those focused on public health e.g. MEDLINE, and Google Scholar. The research was carried out on 19 March 2020. The search for articles concentrated on a combination of key terms including 'influenza', 'pandemic', 'non-pharmaceutical measures', 'non-pharmaceutical interventions', 'social distancing', 'school closures', 'workplace closures', 'mass gatherings', 'hygiene', 'contact tracing', 'travel restrictions', 'quarantine' and 'public health campaigns'. Additional articles were sourced using a snowball approach. To the extent possible, systematic reviews and meta-analyses pertaining to the effectiveness of NPIs were referenced in order to provide an up-to-date summary of the literature. To compare the relative effectiveness of policies, two common outcome measures frequently cited in the literature were identified (i.e. change in the overall attack rate and delay in the peak of disease). Data on these two dimensions was collected from the reviewed papers and compared using standard graphical approaches. Data on other dimensions was also collected and reported in the paper, however, a systematic comparison was not possible due to heterogeneity in the measures used. Finally, policies being utilised by countries to combat COVID-19 were obtained from the grey literature, in particular official government websites and documents.