The major predictors of testing positive for COVID-19 among symptomatic hospitalized patients

Abstract

Introduction Increasing corona virus disease 2019 (COVID-19) pre-test probability can minimize testing patients who are less likely to have COVID-19 and therefore reducing personal protective equipment and COVID-19 testing kit use. The aim of this study was to identify patients who were likely to test positive for COVID-19 among symptomatic patients suspected of having COVID-19 during hospitalization by comparing COVID-19 positive and negative patients. Method We conducted a retrospective chart review of patients who were ≥18 years old and underwent COVID-19 Polymerase chain reaction test because they presented with symptoms thought to be due to COVID-19. The Poisson regression analysis was conducted after clinical presentation, demographic, medical co-morbidities, laboratory and chest image data was retrieved from the medical records. Results Charts of 277 and 35 COVID-19 negative and positive patients respectively were analyzed. Dyspnea (61%) was the most common symptom among COVID-19 negative patients, while 83% and 77% COVID-19 positive patients had cough and fever respectively. COVID-19 positive patients were more likely to present initially with cough [1.082 (1.022 - 1.145)] and fever [1.066 (1.013 - 1.122)], besides being males [1.066 (1.013 - 1.123)] and 50 to 69 years old [1.090 (1.019 - 1.166)]. Dyspnea, weakness, lymphopenia and bilateral chest image abnormality were not associated with COVID-19 positivity. COVID-19 positive patients were less likely to have non-COVID-19 respiratory viral illness [0.934 (0.893 - 0.976)], human immunodeficiency virus [0.847 (0.763 - 0.942)] and heart failure history [0.945 (0.908 - 0.984)]. Other chronic medical problems (hypertension, diabetes mellitus, chronic obstructive pulmonary disease and coronary artery disease) were not associated with testing positive for COVID-19. Conclusion Cough and fever are better predictors of symptomatic COVID-19 positivity during hospitalization. Despite published studies reporting a high prevalence of lymphopenia among COVID-19 positive patients, lymphopenia is not associated with the risk of testing positive for COVID-19.