Clinical diagnosis of SARS-CoV-2 infection: An observational study of respiratory tract infection in primary care in the early phase of the pandemic
van der Velden AW., Shanyinde M., Bongard E., Böhmer F., Chlabicz S., Colliers A., García-Sangenís A., Malania L., Pauer J., Tomacinschii A., Yu LM., Loens K., Ieven M., Verheij TJ., Goossens H., Vellinga A., Butler CC.
Background: Early in the COVID-19 pandemic, GPs had to distinguish SARS-CoV-2 from other aetiologies in patients presenting with respiratory tract infection (RTI) symptoms on clinical grounds and adapt management accordingly. Objectives: To test the diagnostic accuracy of GPs’ clinical diagnosis of a SARS-CoV-2 infection in a period when COVID-19 was a new disease. To describe GPs’ management of patients presenting with RTI for whom no confirmed diagnosis was available. To investigate associations between patient and clinical features with a SARS-CoV-2 infection. Methods: In April 2020–March 2021, 876 patients (9 countries) were recruited when they contacted their GP with symptoms of an RTI of unknown aetiology. A swab was taken at baseline for later analysis. Aetiology (PCR), diagnostic accuracy of GPs’ clinical SARS-CoV-2 diagnosis, and patient management were explored. Factors related to SARS-CoV-2 infection were determined by logistic regression modelling. Results: GPs suspected SARS-CoV-2 in 53% of patients whereas 27% of patients tested positive for SARS-CoV-2. True-positive patients (23%) were more intensively managed for follow-up, antiviral prescribing and advice than true-negatives (42%). False negatives (5%) were under-advised, particularly for social distancing and isolation. Older age (OR: 1.02 (1.01–1.03)), male sex (OR: 1.68 (1.16–2.41)), loss of taste/smell (OR: 5.8 (3.7–9)), fever (OR: 1.9 (1.3–2.8)), muscle aches (OR: 2.1 (1.5–3)), and a known risk factor for COVID-19 (travel, health care worker, contact with proven case; OR: 2.7 (1.8–4)) were predictive of SARS-CoV-2 infection. Absence of loss of taste/smell, fever, muscle aches and a known risk factor for COVID-19 correctly excluded SARS-CoV-2 in 92.3% of patients, whereas presence of 3, or 4 of these variables correctly classified SARS-CoV-2 in 57.7% and 87.1%. Conclusion: Correct clinical diagnosis of SARS-CoV-2 infection, without POC-testing available, appeared to be complicated.