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

ObjectiveTo assess the impact of different phase-out measures approved by several European governments.DesignThis is a longitudinal observational study.SettingsEuropean countries, from 20 February 2020 to 11 May 2020.ParticipantsAll European countries that implemented at least one phase-out measure dictated by governments, during the follow-up period.Main outcomeNew COVID-19 cases, analysed as daily rate by countries.MethodsWe 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.ResultsAfter 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.ConclusionThe 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.

Automated summary

This study aims to assess the impact of different phase-out measures approved by several European governments on new COVID-19 cases. The study found that certain phase-out measures implemented in Italy, Spain, and Denmark had a moderate impact on the daily number of new confirmed cases, while other significant measures applied in other countries had no impact. The proposed indices can be used to quantify the impact of these measures and assist other countries in making decisions. Monitoring the effectiveness of these measures over time can minimize the negative effects on citizens.