COVID-19 pandemic: Are hard lockdowns ineffective?: Why the Bendavid et al. Study does not provide sufficient evidence for this Assumption

Abstract

Background During the Corona pandemic, many countries implemented restrictions on daily life to contain the spread of severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2) These measures varied by country, depending on the region and the rate of infections A group of Stanford University researchers led by Prof John Ioannidis concluded, based on an analysis of existing data from 10 countries, that a hard lockdown, compared with less restrictive measures, did not offer significant benefits in reducing infection rates The publication of the study (Bendavid et al ) is being used in social media as evidence that lockdowns have no significant benefit in containing the spread of SARS-CoV-2 Methods Six researchers independently assessed the methodological quality of the study The internationally accepted assessment tool ROBINS-I (Risk Of Bias in Non-randomized Studies of Interventions) was applied, which is divided into seven domains Conflicts in the evaluation were resolved by consensus Risk of bias in results was graded as low, moderate, or high using an adapted three-tiered scheme Results The study by Bendavid et al has serious methodological flaws The study was rated as having high risk of bias in four of seven domains One of the most serious shortcomings related to confounding factors: the countries that were compared applied measures at different intensities, and the effectiveness of those measures varied depending on the baseline situation Crucial information on the criteria used to select the countries included in the study, as well as a clear definition of the interventions, were missing Conclusions The results of the study have a high potential for bias and should not be used as a basis for decision-making © Deutscher Arzteverlag