JMIR Publications

ABSTRACT

Background:

The impact of the first wave of SARS-CoV-2 in Spain was dramatic, with some of the worst figures in Europe. Strong non-pharmaceutical interventions (NPIs) were implemented to reduce the disease burden.

Objective:

A thorough analysis of the epidemic evolution allows to analyze the impact of the NPIs and their interplay with human behaviour. Such analysis is crucial for the design of future mitigation strategies of COVID-19 and to ameliorate epidemic preparedness in general.

Methods:

We combine a national as well as regional backward analysis of pandemic incidence with large-scale mobility data to determine the impact and timing of authorities’ non-pharmaceutical interventions to fight COVID-19. Furthermore, we contrast this with a model-based inference of hospitalizations and fatalities. The model-based inference allows us to build counterfactual scenarios that evaluate the impact of a later initiation of the epidemic response.

Results:

Our study reveals that the epidemic response previous to the national lockdown, that includes regional measures and individual awareness, substantially contributed to the reduction of the disease burden in Spain. Mobility data shows that individuals adapted their behaviour previous to the national lockdown dependent on the epidemiological situation in their respective regions. The counterfactual scenarios indicate that the absence of an epidemic response previous to lockdown would have resulted in 45’400 (CI: 37’400 - 58’000) fatalities and 182’600 (CI: 150’400 - 233’800) hospitalizations compared to 27’800 and 107’600 that were reported.

Conclusions:

Our results highlight the relevance of the prevention measures self-adopted by the population and regional NPIs prior to the implementation of the national lockdown in Spain. This underlines the crucial interplay between NPIs, epidemic evolution and human behaviour. Such interdependence poses a challenge to predict the impact of NPIs before their implementation.