Testing of Nursing Home Staff Was a Key COVID-19 Mitigation Strategy During the Pandemic. Was It Worth It?

Prior to vaccines, more staff tests per week could have prevented thousands of nursing home deaths, study suggests

Prior to the widespread availability of COVID-19 vaccines, surveillance testing, meaning the testing of asymptomatic individuals for signs of COVID-19, was a key prevention strategy. Struggling to keep doors open as outbreaks forced temporary closures everywhere, many universities, health care facilities and airports swabbed every nose that came inside their facilities for signs of disease. Other employers, from restaurant owners to widget makers, routinely tested workers, often weekly, before allowing them to clock in.

It’s unclear if employers will do the same if COVID-19 makes business as usual difficult again. Research shows that regular testing of asymptomatic workers did reduce transmission, staff shortages and deaths. But questions remain about how often an employer should test to be useful and other practical details. Moreover, public discourse is still not in agreement over whether mandatory workplace testing for COVID-19 is worth the cost, disruption and contention.  

A study in the New England Journal of Medicine asks whether more frequent staff testing schedules limited the number of COVID-19 infections and deaths in nursing facilities, where repercussions of passing on the virus are particularly dire. At least a third of early pandemic deaths, and possibly more, occurred in long-term care facilities. 

In this study, University of Rochester’s Brian E. McGarry, UCLA Anderson’s Ashvin Gandhi and Harvard’s Michael L. Barnett tap a database of mandatory weekly COVID-19 reporting from 13,424 nursing homes to conduct one of the few large studies comparing testing strategies in the real world. They leveraged their estimates to compare expected COVID-19 cases and deaths among residents should facilities implement testing plans similar to the most- (top 10%) and least- (bottom 10%) frequently testing facilities. 

Frequent staff testing was especially beneficial for preventing cases and deaths in the era before vaccines became available, the study finds. One additional test per staff member per week during this time was associated with 30% fewer resident cases and 26% fewer deaths, according to the researchers’ calculations. The findings suggest that the extra effort might have prevented some 3,843 resident deaths in just the nine weeks up to the December 2020 vaccine rollout.

As vaccines became available, the advantages of more frequent testing faded, the study finds. COVID-19 case rates when the omicron variant broke out remained lower among residents at facilities that tested staff most often, but no differences in COVID-19 death rates between high- and low-testing facilities were found. 

Looking at the types of tests used, the study finds few differences between facilities using rapid antigen tests for surveillance compared with those relying on the more expensive polymerase chain reaction tests. Although PCR tests are considered more accurate, they require lab processing, which can cause delays in getting rest results. In contrast, rapid antigen tests produce results in as little as 10 minutes. 

How Often Was Enough?

The findings in this real-world study support conclusions in modeling studies that testing at least twice a week in high-risk settings, using non-PCR tests with quicker turnaround times, was most effective in reducing deaths, the authors note. 

They base their findings on cases and deaths “per 100 potential outbreaks,” a metric that helps account for differences in sizes of facilities and exposure. A “potential outbreak,” Gandhi explains in an email, is the time when a facility goes from having no cases to some. The findings reflect how the resident population fared after these outbreaks.

The difference between a 90th percentile (a high-testing facility) facility and a 10th percentile (low testing) facility is about 1.1 tests per week per staff member, Gandhi says. 

Benefits of More Testing Decline With Vaccinations

Looking across all potential outbreaks between Nov. 22, 2020, and March 20, 2022, facilities with the top rates of testing reported about 12% fewer COVID-19 cases among residents and 15% fewer deaths than facilities with the lowest testing rates. 

The benefits and limitations of aggressive surveillance become more apparent when those results are broken down by outbreaks before and after COVID-19 vaccines became available. 

Conversely, rates of infection and death were very similar across facilities before and during the omicron variant wave from Jan. 18, 2021, to Oct. 31, 2021, the study finds. 

The authors note that vaccine efficacy helps explain why the benefits of aggressive testing schedules faded. The vaccines were very good at preventing infections and severe disease, especially at first. They were less effective in preventing outbreaks during the omicron variant but remained very effective at preventing hospitalizations and deaths, according to the research consensus.