The Utility of rRT-PCR in Diagnosis and Assessment of Case-fatality rates of COVID-19 In the Iranian Population – Positive Test Results are a Marker for Illness Severity

The utility of PCR-based testing in characterizing patients with COVID-19 and the severity of their disease remains unknown. We performed an observational study among patients presenting to hospitals in Iran who were tested for 2019-nCoV viral RNA by rRT-PCR between the fourth week of February 2020 to the fourth week of March 2020. Frequency of symptoms, comorbidities, intubation, and mortality rates were compared between COVID-19 positive vs. negative patients. 96103 patients were tested from 879 hospitals. 18754 (19.5%) tested positive for COVID-19. Positive testing was more frequent in those 50 years or older. The prevalence of cough (54.5% vs. 49.7%), fever (49.5% vs. 44.7%), and respiratory distress (43.0% vs. 39.0%) but not hypoxia (46.9% vs. 56.7%) was higher in COVID-19 positive vs. negative patients (p<0.001 for all). More patients had cardiovascular diseases (10.6% vs. 9.5%, p<0.001) and type 2 diabetes mellitus (10.8% vs. 8.7%, p<0.001) among COVID-19 positive vs. negative patients. There were fewer patients with cancer (1.1%, vs. 1.4%, p<0.001), asthma (1.9% vs. 2.5%, p<0.001), or pregnant (0.4% vs. 0.6%, =0.001) in COVID-19 positive vs. negative groups. COVID-19 positive vs. negative patients required more intubation (7.7% vs. 5.2%, p<0.001) and had higher mortality (14.6% vs. 6.3%, p<0.001). Odds ratios for death of positive vs negative patients range from 2.01 to 3.10 across all age groups. In conclusion, COVID-19 test-positive vs. test-negative patients had more severe symptoms and comorbidities, required higher intubation, and had higher mortality. rRT-PCR positive result provided diagnosis and a marker of disease severity in Iranians. ### Competing Interest Statement The authors have declared no competing interest. ### Funding Statement This manuscript was in part funded by a NIH/NHLBI award RHL135767A (NHLBI Outstanding Investigator Award)to A.M. ### Author Declarations All relevant ethical guidelines have been followed; any necessary IRB and/or ethics committee approvals have been obtained and details of the IRB/oversight body are included in the manuscript. Yes All necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived. Yes I understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance). Yes I have followed all appropriate research reporting guidelines and uploaded the relevant EQUATOR Network research reporting checklist(s) and other pertinent material as supplementary files, if applicable. Yes all data presented are available upon request