Assessing the impact of the phase-out measures during COVID-19 pandemic, using regression models: a longitudinal...

To assess the impact of different phase-out measures approved by several European governments.

This is a longitudinal observational study.

European countries, from 20 February 2020 to 11 May 2020.

All European countries that implemented at least one phase-out measure dictated by governments, during the follow-up period.

New COVID-19 cases, analysed as daily rate by countries.

We compared the observed versus the predicted rates of new confirmed cases, hospital admission, intensive care unit (ICU) admission and deaths by regions in Spain, to assess the accuracy of the proposed generalised estimating equations and hurdle models. Based on these models, we defined and calculated two indices to quantify the impact of the phase-out measures approved in several European countries.

After 2-month follow-up, we confirmed the good performance of these models for the prediction of the incidence of new confirmed cases, hospital admission, ICU admission and death in a 7-day window. We found that certain phase-out measures implemented in Italy, Spain and Denmark showed moderate impact in daily new confirmed cases. Due to these different phase-out measures, in Italy, the estimated increment of new confirmed cases per 100 000 inhabitants was 4.61, 95% CI (4.42 to 4.80), in Spain 2.58, 95% CI (2.54 to 2.62) and in Denmark 2.55, 95% CI (2.40 to 2.69). Other significant measures applied in other countries had no impact.

The two indices proposed can be used to quantify the impact of the phase-out measures and to help other countries to make the best decision. Monitoring these phase-out measures over time can minimise the negative effects on citizens.