Mass screening vs lockdown vs combination of both to control COVID-19: A systematic review

Coronavirus disease 2019 (COVID-19) is a global pandemic. Non-pharmacological interventions, such as lockdown and mass testing, remain as the mainstay of control measures for the outbreak. We aim to evaluate the effectiveness of mass testing, lockdown, or a combination of both to control COVID-19 pandemic. A systematic search on 11 major databases was conducted on June 8, 2020. This review is registered in Prospero (CRD420201 90546). We included primary studies written in English which investigate mass screening, lockdown, or a combination of both to control and/or mitigate the COVID-19 pandemic. There are four important outcomes as selected by WHO experts for their decision- making process: incident cases, onward transmission, mortality, and resource use. Among 623 studies, only 14 studies met our criteria. Four observational studies were rated as strong evidence and ten modelling studies were rated as moderate evidence. Based on one modelling study, mass testing reduced the total infected people compared to no mass testing. For lockdown, ten studies consistently showed that it successfully reduced the incidence, onward transmission, and mortality rate of COVID-19. A limited evidence showed that a combination of lockdown and mass screening resulted in a greater reduction of incidence and mortality rate compared to lockdown only. However, there is not enough evidence on the effectiveness of mass testing only.