Optimal Strategies to Screen Health Care Workers for COVID-19 in the US with SARS-CoV-2 PCR and IgG Antibody Assays

Background: Transmission of SARS-CoV-2 in health care facilities poses a challenge against pandemic control. Health care workers (HCWs) have frequent and high-risk interactions with COVID-19 patients. We undertook a cost-effectiveness analysis to determine optimal testing strategies for screening HCWs to inform strategic decision-making in health care settings. Methods: We modeled the number of new infections, quality-adjusted life years lost, and net costs related to five testing strategies: (1) no tests, (2) only PCR test, (3) only IgG test, (4) conditional PCR test if IgG test is positive, and (5) concurrent PCR and IgG tests. We applied our model to four strata of HCWs, defined by the presence and timing of clinical presentation. We conducted sensitivity analyses to account for uncertainty in inputs. Findings: When screening asymptomatic and recently symptomatic HCWs, conducting only a PCR test offers the best health outcomes and fewest costs; it is associated with 28-144 fewer new infections over two weeks per 100 HCWs screened compared to no test, and saves between $810-$4,600 per test. When screening HCWs in the late clinical disease stage, PCR testing is associated with 49·5 additional infections per 100 HCWs screened compared to no screening. Depending on the degree of immunity conferred, IgG testing may avoid up to 3·7 additional infections. Interpretation: PCR testing is a beneficial strategy to identify infected HCWs and reduce transmission of SARS-CoV-2 in health care settings. Utility of IgG testing depends on the time when the test is administered and immunity characteristics. More evidence is needed on the latter to better inform policy decisions. Funding: None received. Declaration of Interests: Authors declare no conflicts of interest.