Temperature Screening for SARS-CoV-2 in Nursing Homes: Evidence from Two National Cohorts

J Am Geriatr Soc. 2020 Oct 9. doi: 10.1111/jgs.16876. Online ahead of print.

Abstract

Background/objectives: Infection screening tools classically define fever as 38.0°C (100.4°F). Frail older adults may not mount the same febrile response to systemic infection as younger or healthier individuals. We evaluate temperature trends among nursing home (NH) residents undergoing diagnostic SARS-CoV-2 testing and describe the diagnostic accuracy of temperature measurements for predicting test-confirmed SARS-CoV-2 infection.

Design: Retrospective cohort study evaluating diagnostic accuracy of pre-SARS-CoV-2 testing temperature changes.

Setting: Two separate NH cohorts tested diagnostically (e.g., for symptoms) for SARS-CoV-2. PARTICIPANTS Veterans residing in Veterans Affairs (VA) managed NHs and residents in a private national chain of community NHs.

Measurements: For both cohorts, we determined the sensitivity, specificity, and Youden's index with different temperature cutoffs for SARS-CoV-2 polymerase chain reaction results.

Results: The VA cohort consisted of 1,301 residents in 134 facilities from March 1, 2020, to May 14, 2020, with 25% confirmed for SARS-CoV-2. The community cohort included 3,368 residents spread across 282 facilities from February 18, 2020, to June 9, 2020, and 42% were confirmed for SARS-CoV-2. The VA cohort was younger, less White, and mostly male. A temperature testing threshold of 37.2°C has better sensitivity for SARS-CoV-2, 76% and 34% in the VA and community NH, respectively, versus 38.0°C with 43% and 12% sensitivity, respectively.

Conclusion: A definition of 38.0°C for fever in NH screening tools should be lowered to improve predictive accuracy for SARS-CoV-2 infection. Stakeholders should carefully consider the impact of adopting lower testing thresholds on testing availability, cost, and burden on staff and residents. Temperatures alone have relatively low sensitivity/specificity, and we advocate any threshold be used as part of a screening tool, along with other signs and symptoms of infection.

Keywords: COVID-19; SARS-CoV-2; aged 80 and older; nursing homes; temperature.