A New Model for Assessing COVID-19 Risk in Workplaces and Universities
Verily’s data scientists recently published their epidemiological model, the “Community-Workplace” model, in PLOS-ONE journal. The goal of the model was to better understand potential risk levels for COVID-19 transmission in the workplace and to determine what testing strategies would be needed as more employees return to office and as students return to school. The scenario-based model helps explain the undeniable importance between COVID-19 transmission within the workplace, within the surrounding community, and between them. The model also forecasts the impact of COVID-19 testing across different scenarios.
By evaluating differences in environments - an office workplace, a factory floor, and a university campus - researchers sought to understand the impact of various mitigation strategies to support reopenings. It specifically evaluates the impact of COVID-19 testing and how different testing levels impact “peak prevalence” of COVID-19 in the workplace. Peak prevalence is the maximum percentage of the employee or university population who tested COVID-positive during a given time period. Testing is an important step to detect infected individuals and remove them from the workplace in order to prevent them from spreading the infection. Another critical benefit of testing is leveraging the aggregated test results to continuously estimate infection prevalence in the workforce. With timely updates, actions can be taken to prevent emerging outbreaks from growing. Specifically for each worksite or campus,we can apply the model to predict the path to lower peak prevalence using testing strategies based on work environment and community peak levels (see chart).
Maintaining a peak prevalence below 3% can be achieved in an office setting by testing its workforce every two weeks, whereas achieving this same goal for a university could require as much as fourfold more testing (i.e., testing the entire campus population twice a week).
The more time is spent together in a high-contact workplace environment, the more testing of individuals is required to keep infection at safe levels. To maintain lower than a 3% peak prevalence in the workforce, the “Office workplace” must test 10% of individuals per work day, the “Factory floor” must test 20% of individuals per work day, and the “University” requires testing of as many as 40% of individuals per work day.
Introducing non-pharmaceutical interventions (NPIs) such as masking and social distancing can reduce peak prevalence. We find that introducing mitigations when the community prevalence of COVID-19 is at 2% prevalence can reduce peak prevalence from 6.8% to 2.3% in the University setting with a continuous testing program.
Tolerance for risk of COVID-19 transmissions may vary by company, and testing strategies should take this into account. For example, reducing capacity in a factory setting may require shutting down a production line that would take several weeks to restart. The model predicts how much testing is required to keep COVID at different peak levels.
Using the Model to Personalize Employer Return to Work Plans - Verily Healthy at Work
The Community-Workplace model outlined in this PLOS-ONE publication is built into Verily’s Healthy at Work program to recommend customized solutions for clients, helping businesses and universities manage to their own risk thresholds when building out their return to work strategies. By careful monitoring of both community outbreaks (using public health data) and worksite cases, Healthy at Work can ensure that employers are best equipped to detect and isolate the infected and suppress virus spread. Creating a safe and secure environment for employees is a core need for any company bringing people back to work. Verily can support targeted recommendations utilizing the model to build more personalized, cost-effective approaches for both employers and universities.
There are a few key things to consider while building your return-to-work solution.
Know your Team. Testing strategies should incorporate features of the workplace such as the degree of close-contact interactions between employees and the amount of time that employees spend at work.
Know your Community. Consider the disease prevalence in the surrounding community, and the rate of change of this prevalence, as it will have a direct impact on the rate of prevalence within employees.
Have a Testing Plan. When fiscally reasonable, continuous testing allows an employer to estimate the current prevalence of infection in the workplace. This gives you the opportunity to introduce mitigations in response to increases in prevalence and reduce workplace spread.