Estimating the impact of non-pharmaceutical interventions on documented infections with COVID-19: A cross-country analysis

Nicolas Banholzer; Eva van Weenen; Bernhard Kratzwald; Arne Seeliger; Daniel Tschernutter; Pierluigi Bottrighi; Alberto Cenedese; Joan Puig Salles; Stefan Feuerriegel; Werner Vach

Efforts to control the spread of SARS-CoV-2 focus on non-pharmaceutical interventions (NPIs). These represent public health-policy measures that are intended to diminish transmission rates and, to this end, aim at reducing person-to-person contacts via so-called social distancing 15 . Examples include school closures 16 , bans on (mass) gatherings 17 , travel restrictions 18, 19 , and even complete lockdowns (e.g., as in the case of France, Spain, and Italy). The impact of NPIs has been primarily studied through theoretical simulations [18] [19] [20] [21] [22] [23] [24] [25] [26] . Inferences from observational data are primarily of a descriptive nature 14 , focus on single country (i.e., China 27,28 ), or model death rates due to COVID-19 before and after the implementation of NPIs 29 . In contrast, the impact of NPIs in reducing the new COVID-19 cases is unknown. Documented COVID-19 cases, however, are essential for decision-makers in health-policy when monitoring and evaluating the effectiveness of NPIs (e.g., controlling the outbreak in a way that surge capacities are not exceeded).