Unravelling the role of the mandatory use of face covering masks for the control of SARS-CoV-2 in schools: a quasi-experimental study nested in a population-based cohort in Catalonia (Spain)

Abstract

ObjectiveTo assess the effectiveness of mandatory use of face covering masks (FCMs) in schools during the first term of the 2021–2022 academic year.DesignA retrospective population-based study.SettingSchools in Catalonia (Spain).Population599 314 children aged 3–11 years attending preschool (3–5 years, without FCM mandate) and primary education (6–11 years, with FCM mandate).Study periodFrom 13 September to 22 December 2021 (before Omicron variant).InterventionsA quasi-experimental comparison between children in the last grade of preschool (5 years old), as a control group, and children in year 1 of primary education (6 years old), as an interventional group.Main outcome measuresIncidence of SARS-CoV-2, secondary attack rates (SARs) and effective reproductive number (R*).ResultsSARS-CoV-2 incidence was significantly lower in preschool than in primary education, and an increasing trend with age was observed. Six-year-old children showed higher incidence than 5 year olds (3.54% vs 3.1%; OR 1.15 (95% CI 1.08 to 1.22)) and slightly lower but not statistically significant SAR (4.36% vs 4.59%; incidence risk ratio 0.96 (95% CI 0.82 to 1.11)) and R* (0.9 vs 0.93; OR 0.96 (95% CI 0.87 to 1.09)). Results remained consistent using a regression discontinuity design and linear regression extrapolation approaches.ConclusionsWe found no significant differences in SARS-CoV-2 transmission due to FCM mandates in Catalonian schools. Instead, age was the most important factor in explaining the transmission risk for children attending school.

WITHDRAWN: Physio-metabolic and clinical consequences of wearing face masks -Systematic review with meta-analysis and comprehensive evaluation

“…Based on the facts we have found, the use of face mask in the hope of maintaining health is unfortunately contradicting the WHO's definition of health. Regarding all the possible side effects of mask and their still unproven efficacy against viral transmission within the general population 4,[160][161][162] , health seems not to be substantially preserved by wearing face masks. So far, only two randomized controlled mask trials for prevention of SARS-CoV-2 infection in the general population have been published: one high quality study from Denmark, Europe 163 , and the other from Bangladesh with biased results and a lot of inconsistencies 164 .…”

“…The paucity in high-quality mask studies is unfortunate. Seeing the overall weak evidence for efficacy of masks against viral transmission within the general population 4,[160][161][162][166][167][168] , face masks have to be evaluated appropriately in the sense of the Hippocratic Oath and as per the Primum nihil nocere (above all do not harm). To avoid at all costs that the damage caused by preventive or therapeutic measures becomes greater than that caused by the disease itself, should be the credo of all those involved in the containment of the crisis, including politicians and the socalled experts.…”

Face coverings have little utility for young school-aged children

“…A new, elegantly designed, quasi-experimental study from Catalonia, Spain, by Coma et al 8 helps to shed light on the efficacy of masks for younger, school-aged children in educational settings. The benefit of this study design is that unlike other observational studies, the settings in which masks are used differ only in the age of the children; those in the first year of primary school wearing face coverings and those in the last year of preschool do not.…”

Lack of correlation between school mask mandates and paediatric COVID-19 cases in a large cohort

“…Importantly, too, the findings of these studies were inconsistent with more rigorously designed observational studies 5 , 6 , 7 including a study using a regression discontinuity design which reported no significant effect of masking on SARS-CoV-2 transmission in Catalonian schools 8 . Furthermore, one randomized study in adults found no impact of community cloth masking and only a marginal impact of surgical masking, though only in those over 50 years of age 9 .…”