Triage Strategies Based on C-Reactive Protein Levels and SARS-CoV-2 Tests among Individuals Referred with Suspected COVID-19: A Prospective Cohort Study

Abstract: Background C-reactive protein (CRP) has prognostic value in hospitalized patients with COVID-19; the importance of CRP in pre-hospitalized patients remains to be tested. Methods: Individuals with symptoms of COVID-19 had a SARS-CoV-2 PCR oropharyngeal swab test, and a measurement of CRP was performed at baseline, with an upper reference range of 10 mg/L. After 28 days, information about possible admissions, oxygen treatments, transfers to the ICU, or deaths was obtained from the patient files. Using logistic regression, the prognostic value of the CRP and SARS-CoV-2 test results was evaluated. Results: Among the 1006 patients included, the SARS-CoV-2 PCR test was positive in 59, and the CRP level was elevated (>10 mg/L) in 131. In total, 59 patients were hospitalized, only 3 of whom were SARS-CoV-2 positive, with elevated CRP (n = 2) and normal CRP (n = 1). The probability of being hospitalized with elevated CRP was 4.21 (95%CI 2.38-7.43, p < 0.0001), while the probability of being hospitalized with SARS-CoV-2 positivity alone was 0.85 (95%CI 0.26-2.81, p = 0.79). Conclusions: CRP is not a reliable predictor for the course of SARS-CoV-2 infection in pre-hospitalized patients. CRP, while not a SARS-CoV-2 positive test, had prognostic value in the total population of patients presenting with COVID-19-related symptoms.