ABSTRACT
OBJECTIVE: To examine the appropriateness of the decision to quarantine healthcare workers (HCWs) exposed to coronavirus disease 2019 (COVID-19). DESIGN: Retrospective cohort study. SETTING: A tertiary-care medical center in Israel. PARTICIPANTS: HCWs exposed to a coworker infected with severe acute respiratory coronavirus virus 2 (SARS-CoV-2). METHODS: Quarantined and nonquarantined HCWs were followed for up to 1 month following exposure and their COVID-19 status was determined. The validity of the decision to quarantine was assessed. RESULTS: In total, 2,595 HCWs exposed to 419 confirmed index cases were studied. Of the contact cases, 752 HCWs were quarantined and 1,843 HCWs were not. Of those quarantined, 36 became SARS-CoV-2 positive (4.7%). Among those who were not quarantined, only 13 (0.7%) became SARS-CoV-2 positive, which translated to a sensitivity of 73.5% and a specificity of 71.9% for the decision to quarantine (positive and negative predictive values: 4.7% and 99.3%, respectively). Controlling for confounders, the decision to quarantine the HCW by the Israeli Ministry of Health guidelines was associated with a significant risk of becoming SARS-CoV-2 positive (RR, 3.83; 95% CI, 1.98-7.36; P = .001). If a nonselective policy was used, 11,700 working days would have been lost (902 working days lost per positive case). CONCLUSIONS: An efficient and tight system of HCW contact investigations served its purpose in our hospital during the COVID-19 pandemic. This study was based on HCW reports and reported adherence to safety regulations, and these findings are relevant to the massive pandemic waves due to the SARS-CoV-2 α (alpha) variant. These Methods demonstrate an effective way of handling risk without causing damage due to arbitrary risk-control measures.