This week saw the publication of a suite of systematic reviews by the Royal Society (RS) on the effect of non-pharmaceutical interventions in the pandemic.
Politico headlined with ‘Top review says Covid lockdowns and masks worked, period’. The Guardian led with ‘Lockdowns and face masks “unequivocally” cut the spread of Covid, report finds’, and the i newspaper stated: ‘Masks and social distancing did reduce Covid infections, new report shows, proving lockdown sceptics wrong.’
So there you have it, a slam dunk, sceptics, you were all wrong. You should have masked up and stayed in lockdown.
Even more so when you listen to the Chair of the report’s group, Mark Walport, who said: “There is sufficient evidence to conclude that early, stringent implementation of packages of complementary NPIs was unequivocally effective in limiting SARS-CoV-2 infections.”
Four systematic reviews informed the effectiveness of non-pharmaceutical interventions in the Covid pandemic. However, here is some of what these reviews report.
A systematic review on environmental control measures:
Many of these studies were assessed to have critical risk of bias in at least one domain, largely due to confounding factors that could have affected the measured outcomes. As a result, there is low confidence in the findings.
One study, an RCT, showed that daily testing of contacts could be a viable strategy to replace lengthy quarantine of contacts. Based on the scarcity of robust empirical evidence, we were not able to draw any firm quantitative conclusions about the quantitative impact of TTI interventions in different epidemic contexts.
Effectiveness of face masks for reducing transmission of SARS-CoV-2:
We analysed 35 studies in community settings (three RCTs and 32 observational) and 40 in healthcare settings (one RCT and 39 observational). Ninety-one percent of observational studies were at ‘critical’ risk of bias (ROB) in at least one domain, often failing to separate the effects of masks from concurrent interventions.
