Real-world diagnostic value of a nationwide standardized COVID-19 triage chart in Turkey

Effective triage is critical during the coronavirus disease 2019 (COVID-19) pandemic. An appropriate triage plan is crucial to direct suspected COVID-19 cases to a designated area, in order to separate such patients from other patients and staff.

To report the diagnostic value of the "Possible Coronavirus Disease 2019 (COVID-19) Case Questioning Guide for Outpatients", a nationwide standard triage chart, and of the individual questions within the triage chart for detecting COVID-19 in patients admitted to our hospital.

A total of 39,681 outpatients admitted to our hospital between April 1 and April 30, 2021, underwent triage questioning. The triage chart consisted of 3 symptom questions and 4 contact and travel questions. Patients who responded "yes" to at least 1 question were referred to the pandemic area; others were considered low-risk and did not undergo routine COVID-19 polymerase chain reaction (PCR) test.

Briefly, 3529 outpatients were referred to the pandemic area; among them, 1055 were PCR-positive. Among 36,152 low-risk patients, 94 were PCR-positive. The sensitivity of the triage chart was 91.82%, specificity was 93.58%, positive likelihood ratio was 14.30, and negative likelihood ratio was 0.09. Triage questions were in moderate agreement with PCR results (Cohen's Kappa: 0.429, p < 0.0001). The diagnostic value of the triage chart was mainly attributed to the questions regarding possible COVID-19 infection symptoms rather than contact history. However, the questions included in the triage chart had none to slight agreement with the PCR test results in the pandemic outpatients.

The triage chart has high sensitivity and specificity for discriminating possible COVID-19 cases in all outpatients, but has unsatisfactory diagnostic value for predicting PCR positivity in pandemic outpatients. Therefore, the current triage chart should be used accordingly, i.e., to define possible COVID-19 cases rather than PCR-positive cases. Further studies regarding COVID-19 triage for possible and PCR-positive cases should also focus on the individual diagnostic value of less prevalent symptoms.