Repeated Temperature Readings with Patient Baseline Increases Sensitivity for COVID-19 Detection among Elderly Veterans
BACKGROUND:
Older people with chronic illness are at greatest risk for severe COVID-19 (SARS-CoV-2) outcomes. Because threshold symptoms and signs, such as a temperature of at least 38°C (100.4°F), have been used to determine who is tested for the virus, their frequency may underestimate the prevalence of COVID-19. Studies have reported that nursing home residents with pneumonia often present without fever and have a lower basal temperature than community-dwelling older adults. On March 10, 2020, VA issued isolation and temperature guidance, including daily monitoring, to its Community Living Centers (CLCs) that provide a nursing home environment for nearly 9,000 Veterans. And on April 14, 2020, VA guidance required one-time universal COVID-19 testing of all CLC residents and staff. The purpose of this study was to compare temperature trends and identify maximum temperatures in nursing home residents 14 days prior to and following systematic testing among CLC residents. Using VA electronic medical records data, investigators identified COVID-19 testing results for 7,325 Veterans residing in CLCs. Of these CLC residents, 453 (6%) of Veterans tested positive for COVID-19.
FINDINGS:
- A single temperature screening is unlikely to accurately detect COVID-19 in nursing home residents. Only 27% of residents who tested positive for the virus met the temperature threshold (38°C or 100.4°F) during the study period.
- While most nursing home residents (63%) with confirmed COVID-19 experienced two or more 0.5°C elevations above their baseline temperatures, there also was a group (20%) that was persistently cooler and had no temperature deviation from baseline.
- Temperatures in elderly Veterans with COVID-19 began rising 7 days prior to testing for the virus – and remained elevated during the 14-day follow-up.
- The average maximum temperature in COVID-19 positive patients was 37.66°C (99.8°F) compared to 37.11°C (98.8°F) in patients who were COVID-19 negative.
IMPLICATIONS:
- Study findings suggest that the current fever threshold for COVID-19 screening should be reconsidered. Repeated temperature measurement with a patient-derived baseline could increase sensitivity for surveillance purposes when applied to a nursing home population.
LIMITATIONS:
- Investigators did not distinguish sensitivity of temperature thresholds for detecting COVID-19 when separated between those who met other symptom screening criteria from those who did not.
AUTHOR/FUNDING INFORMATION:
This study was partly funded by HSR&D. Drs. Rudolph (Director), Gravenstein (Associate Director), Mor, and McConeghy, and Mr. Halladay and Ms. Barber are part of HSR&D’s Center of Innovation in Long-Term Services and Supports for Vulnerable Veterans (LTSS) in Providence, RI.
Rudolph J, Halladay C, Barber M, et al. Temperature in Nursing Home Residents Systematically Tested for SARS-CoV-2. Journal of the American Medical Directors Association. Abstract published June 8, 2020.