Michael L. Barnett, MD

Credit: hsph.harvard.edu

Increases in surveillance testing of skilled nursing facility staff is associated with COVID-19 case and death reductions among the facilities’ residents, according to recent findings.¹

Although there was a widespread acceptance of surveillance testing for COVID-19 in nursing facilities among workers, there was less available data prior to this study on testing’s effects on residents of these facilities.²

Consequently, it was seen as an invaluable topic of exploration. The research was conducted in a retrospective cohort study, and authored by Michael L. Barnett, MD, from the Harvard T.H. Chan School of Public Health at Brigham and Women’s Hospital.

“The large size of the nursing home industry—1.7 million staff and more than 4 million short- and long-stay residents—and substantial variation in adoption of surveillance testing across more than 15,000 facilities provide a unique opportunity to evaluate the real-world effectiveness of surveillance testing approaches,” Barnett and colleagues wrote.

Background and Findings

The investigators collected data that had been taken from 2020 to 2022, using a retrospective cohort study of COVID-19 testing from 3 periods of the pandemic. The data collected was from staff members of 13,424 different skilled nursing facilities.

The periods into which the investigators’ data was collected were divided as follows:

• Prior to vaccine approval
• Pre-omicron variant wave
• During the omicron wave

The researchers evaluated total cases of COVID-19, resident deaths at the time of possible outbreaks (defined by the team as case occurrence following 2 weeks without cases), and the testing volumes of staff.

Additionally, the investigators looked into adjusted differences between facilities in the 90th percentile of testing numbers and those in the 10th percentile in outcomes. They also used weekly virus case numbers as well as virus-connected deaths among facility residents at the time of possible outbreaks.

Results of the research team’s research showed that residents in high-testing nursing facilities reported 519.7 virus cases per 100 outbreaks, compared to 591.2 among those in low-testing nursing facilities (adjusted difference, −71.5; 95% confidence interval [CI], −91.3 to −51.6).

The team also noted that in the same time period, 42.7 deaths per 100 possible outbreaks were reported versus 49.8 deaths in high and low-testing settings, respectively (adjusted difference, −7.1; 95% CI, −11.0 to −3.2).

The investigators added that before vaccines were widely available, there were 759.9 and 1060.2 reported cases per 100 possible outbreaks in the high and low-testing settings, respectively (adjusted difference, −300.3; 95% CI, −377.1 to −223.5). They found that fewer deaths were reported in high-testing settings compared to low-testing, with 125.2 and 166.8 deaths, respectively (adjusted difference, −41.6; 95% CI, −57.8 to −25.5).

COVID-19 case and death numbers were found to have been similar in both settings before omicron, but during the variant’s outbreak, high-testing facilities showed a lower number of reported cases among residents. That said, death numbers were comparable for both testing groups.

“Greater surveillance testing of staff members at skilled nursing facilities was associated with clinically meaningful reductions in Covid-19 cases and deaths among residents, particularly before vaccine availability,” the investigators wrote.

References

1. ^{McGarry, BE, Gandhi AD, Barnett ML, et al. Covid-19 Surveillance Testing and Resident Outcomes in Nursing Homes. The New England Journal of Medicine. Published March 23, 2023. Accessed April 11, 2023.}
2. ^{Chin ET, Huynh BQ, Chapman LAC, Murrill M, Basu S, Lo NC. Frequency of routine testing for coronavirus disease 2019 (COVID-19) in high-risk healthcare environments to reduce outbreaks. Clin Infect Dis 2021;73(9):e3127-e3129.}