Association between rRT-PCR test results upon admission and outcome in hospitalized chest CT-Positive COVID-19 patients; a provincial retrospective cohort with active follow-up

Background The Covid-19 pandemic imposed the most devastating challenge on healthcare systems worldwide. Iran was among the first countries that had to confront serious shortages in RT-PCR testing for SARS-CoV-2 and ventilators availabilities throughout the COVID-19 outbreak. This study aimed to investigate the clinical course of hospitalized COVID-19 patients with different rRT-PCR test results during the first 3 weeks of the outbreak in Qazvin province, Iran. Methods For this retrospective cohort study, data of hospitalized patients primarily diagnosed as having COVID-19 in all 12 centers across the whole Qazvin province during Feb 20-Mar 11, 2020 was analyzed. A multivariate logistic regression model was applied to assess the independent associates of death among COVID-19 patients. Results 998 patients (57% male, median age 54 years) with positive chest CT-scan changes were included in this study. Among them, 558 patients were examined with rRT-PCR test and 73·8% tested positive. Case fatality rate was 20·68% and 7·53% among test-positive and test negative hospitalized patients, respectively. While only 5·2% of patients were ICU admitted, case fatality rates outside ICU were 17·70% and 4·65% in test-positive and test-negative non-ICU admitted patients, correspondingly. The independent associates of death were age ≥ 70 years, testing positive with rRT-PCR test, having immunodeficiency disorders and ICU admission. Conclusions Hospitalized COVID-19 patients with mild symptoms despite positive chest CT changes and major comorbidities were more probable to have negative rRT-PCR test result, hence lower case fatality rate and a more favorable outcome.