Risk stratification strategies for shielding

Bottom Line:

Risk stratification strategies to selectively distribute shielding provide a potential approach to easing social restrictions while attenuating the spread of COVID-19


Smith, G.D. & Spiegelhalter, D. Shielding from covid-19 should be stratified by risk. BMJ (2020). https://doi.org/10.1136/bmj.m2063

Date Published:

28 May 2020


Risk stratification for mortality due to COVID-19 to identify and shield the vulnerable has been proposed as a potential strategy to address the immense burden of lockdowns while promoting public safety during the COVID-19 pandemic. Numerous variations of the model exist with incongruency in best determining the end-point to shielding practices.  Shielding could be implemented until herd immunity is reached in the unshielded groups or could involve a group composed of individuals identified as immune or repeatedly tested for infection. Selection criteria for identifying groups at higher risk of mortality due to COVID-19 should be able to be easily conveyed and understood by the public. Age has been shown to be a strong predictor of COVID-19 mortality but may provide insufficient stratifying power alone. Other risk factors including ethnicity, comorbidities, and geographical information should be considered to develop risk scoring systems. Populations would be classified into groups according to their score and provided appropriate guidance. It is important to recognize the limits of the “stratify and shield” strategy including its inability to determine risk at the individual level. Challenges in implementing stratified shielding need to be also addressed such as social acceptance and response as well as barriers to shielding practices in working environments. Nonetheless, the negative and deep consequences of social restrictions and lockdowns on the daily lives of individuals demand that serious considerations be given to risk stratification and shielding as an alternative practical approach.  

Summary by: Julia Kim