New Cochrane Review on the effectiveness of quarantine and other public health measures for preventing the spread of Coronavirus

Cochrane has published a new Rapid Review assessing the effectiveness of quarantine during the COVID-19 pandemic.

The review summarizes evidence available from modelling studies that show how quarantining affects the spread of COVID-19. The studies included in the review consistently conclude that quarantine can play a role in controlling the spread of coronavirus SARS-CoV-2. While early implementation of quarantine and its combination with other public health measures helps to ensure effectiveness, key uncertainties remain as to how these measures can best be adopted and when they can be relaxed.                                                                      

This Rapid Review was done in a short space of time as part of Cochrane’s organizational effort to meet the need for up-to-date summaries of evidence to support decision-making in combating the effects and impact of COVID-19.

Cochrane researchers used abbreviated systematic review methods to address the following questions as quickly as possible:

  • Is quarantine of asymptomatic individuals who were in contact with a confirmed or suspected case of COVID-19 effective to control the COVID-19 outbreak?
  • Are there differences in the effectiveness of quarantine in different settings?
  • How effective is quarantine when combined with other interventions, such as case isolation, school closures, or antiviral drugs, in reducing transmission, incidence of diseases, and death?
  • Is quarantine of individuals coming from a country with a declared COVID-19 outbreak effective in controlling the COVID-19 outbreak?

                                                                              

The authors of this Cochrane Review concluded that:

  • Quarantine of people exposed to confirmed cases may avert high proportions of infections and deaths compared to no measures.
  • The effect of quarantine of travelers from a country with a declared outbreak to avert transmission and deaths was small.
  • In general, the combination of quarantine with other prevention and control measures, such as school closures, travel restrictions, and physical distancing, had a greater effect on the reduction of transmissions, cases which required critical care beds, and deaths compared with quarantine alone.
  • More comprehensive and early implementation of prevention and control measures may be more effective in containing the COVID-19 outbreak.

The researchers rate their confidence in the results to be low or very low because of the way that the models used in the studies were developed. They are based on assumptions about the true prevalence of infection, which could be updated when we know more about this aspect of the COVID-19 pandemic.