Quarantine for controlling COVID-19 (coronavirus). New Cochrane evidence

Sarah Chapman looks at a Cochrane Rapid Review, published yesterday, with evidence from mathematical modelling studies on the effectiveness of quarantine for controlling the spread of COVID-19 (coronavirus).

Last month I blogged about two rapid reviews by researchers at King’s College London on what makes people more likely to follow quarantine rules and what makes it more tolerable. Yesterday, Cochrane published a rapid review on how quarantine affects the spread of COVID-19 (coronavirus).

What is quarantine?

All over the world, public health measures are in place with the aim of reducing the spread of COVID-19, a new virus that spreads quickly and for which there is not yet an effective treatment or vaccine. These measures include physical distancing (also called social distancing), isolation and quarantine. Quarantine is the separation and restriction of movement of people who have potentially been exposed to a contagious disease, in order to limit its spread. It  can be applied to individuals or whole communities. It can be voluntary or enforced.

""

What did the researchers want to find out?

They wanted to know how well quarantine works in limiting the spread of COVID-19 and if it reduces the number of deaths from the disease. They also wanted to know if quarantine is more effective if it is done along with other things such as closing schools, social distancing and travel restrictions.

What sort of evidence is this?

A Cochrane Rapid Review

Like all Cochrane Reviews, this Cochrane Rapid Review is a systematic review that brings together the best available evidence from research studies relevant to the review’s question(s). However, it follows a shorter process than usual in the interests of providing evidence quickly. It was commissioned by the World Health Organization and has been done 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.

Based on mathematical modelling studies

It is important to note that the evidence in this review comes from modelling studies that show how quarantine affects the spread of COVID-19. They make assumptions about the viruses and their accuracy won’t be fully known until later. Neil Ferguson, a mathematical epidemiologist at Imperial College London, and lead author of one of the COVD-19 studies included in the review, has reflected on limitations of modelling studies. He pointed out that “We’re building simplified representations of reality. Models are not crystal balls.”

The models in the studies in the Cochrane Rapid Review are based on assumptions about the true prevalence of infection – that’s the percentage of people in a population who are infected. When we have more information about this, from the COVID-19 pandemic, these may look different. So the Cochrane authors rate their confidence in the results to be low or very low.

The review includes 29 studies, of which ten focused on COVID-19. Nineteen other studies looked at SARS (severe acute respiratory syndrome), alone or with other viruses, and MERS (Middle East respiratory syndrome), so these provide only indirect evidence for our current situation with COVID-19. The ten COVID-19 studies were all modelling studies simulating outbreaks on a cruise ship and in China, the UK, and South Korea.

What’s the bottom line?

The COVID-19 modelling studies in the review consistently report a benefit of quarantine in reducing the number of people who get infected and who die from COVID-19. The studies on SARS and MERS have similar results.

What else does the evidence suggest?

The Cochrane authors also found that putting quarantine in place early and combining it with other public health measures (such as social distancing) seem to be important if it is to be effective in controlling the spread of disease. Early quarantine measures may also mean greater cost-savings are made. The effect of quarantining of travellers from a country with a declared outbreak to reduce disease transmission and deaths was small.

In a press release, lead author Barbara Nußbaumer-Streit talked about the importance of monitoring and reviewing the situation in different localities, saying “This Cochrane Review shows that while quarantine may help in containing the COVID-19 outbreak, decision-makers will need to constantly monitor the outbreak situation locally in order to maintain the best possible balance of measures in place, and that there is an acceptable trade-off between benefits and harms.”

On this page, which is constantly updated, you can stay informed about Cochrane content relating to the coronavirus (COVID-19) pandemic and the various related activities that Cochrane is undertaking in response.

Take-home points

Take-home points • A new Cochrane Rapid Review has found that COVID-19 mathematical modelling studies consistently report a benefit of quarantine in reducing the number of people who get infected with COVID-19 and who die from it. • Decision-makers need to constantly monitor the outbreak situation locally to maintain the best possible balance of measures in place, with an acceptable trade-off between benefits and harms. • 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. More Rapid Reviews, answering other important questions about COVID-19, are underway.

Join in the conversation on Twitter with @CochraneUK @SarahChapman30 or leave a comment on the blog. Please note, we will not publish comments that link to commercial sites or appear to endorse commercial products.

References (pdf)

Sarah Chapman has nothing to disclose.


Sarah Chapman

About Sarah Chapman

view all posts

Sarah's work as a Knowledge Broker at Cochrane UK focuses on disseminating Cochrane evidence through social media, including Evidently Cochrane blogs, blogshots and the ‘Evidence for Everyday’ series for nurses, midwives, allied health professionals and patients. A former registered general nurse, Sarah has a particular interest making evidence accessible and useful to practitioners and to others making decisions about health. Before joining Cochrane, Sarah also worked on systematic reviews for the University of Oxford and the Royal College of Nursing Institute, and obtained degrees in History from the University of Oxford and in the history of women’s health and illness in early modern England (MPhil., University of Reading).

6 Comments on this post

  1. […] Quarantine for controlling COVID-19 (coronavirus). New Cochrane evidence […]

  2. […] Read the Evidently Cochrane blog post ‘Quarantine for controlling COVID-19 (coronavirus). New … […]

  3. […] Read the Evidently Cochrane blog post ‘Quarantine for controlling COVID-19 (coronavirus). New … […]

  4. Avatar

    Sin lugar a dudas que la cuarentena es una medida para frenar el contagió, pero no se podrá mantener la misma de una forma ilimitada, debe estar acompañada de un análisis de los posibles contagiados, y permitir que aquellos que evolucionaron satisfactoriamente de la enfermedad formen el escudo de protección y se incomporen al trabajo para normalizar la actividad económica pues, el hambre es la mejor aliada de las pestes , y tambien traera muertes.

    Maureen / Reply
    • Avatar

      Por el momento no existe evidencia de inmunización resultante de la superacion de la enfermedad. Aun los recuperados, siguen suceptibles a posterior contagio e infeccion.

      rl / (in reply to Maureen) Reply

Leave a Reply

Your email address will not be published. Required fields are marked *

*

UA-49496932-1