J Med Virol. 2021 Apr 30. doi: 10.1002/jmv.27054. Online ahead of print.
ABSTRACT
INTRODUCTION: Pooled testing is a potentially efficient alternative strategy for COVID-19 testing in congregate settings. We evaluated the utility and cost-savings of pooled testing based on imperfect test performance and potential dilution effect due to pooling, and created a practical calculator for online use.
METHODS: We developed a 2-stage pooled testing model accounting for dilution. The model was applied to hypothetical scenarios of 100 specimens collected during a one-week time-horizon cycle for varying levels of COVID-19 prevalence and test sensitivity and specificity, and to 338 skilled nursing facilities (SNFs) in Los Angeles County (Los Angeles) (data collected and analyzed in 2020).
RESULTS: Optimal pool sizes ranged from 1 to 12 in instances where there is a least one case in the batch of specimens. 40% of Los Angeles SNFs had more than one case triggering a response-testing strategy. The median number (minimum; maximum) of tests performed per facility were 56 (14; 356) for a pool size of 4, 64 (13; 429) for a pool size of 10, and 52 (11; 352) for an optimal pool size strategy among response-testing facilities. The median costs of tests in response-testing facilities were $8,250 ($1,100; $46,100), $6,000 ($1,340; $37,700), $6,820 ($1,260; $43,540) and $5,960 ($1,100; $37,380) when adopting individual testing, a pooled testing strategy using pool sizes of 4, 10, and optimal pool size, respectively.
CONCLUSIONS: Pooled testing is an efficient strategy for congregate settings with low prevalence of COVID-19. Dilution as a result of pooling can lead to erroneous false negative results. This article is protected by copyright. All rights reserved.
PMID:33930195 | DOI:10.1002/jmv.27054
