Why is the mortality rate high in RT-PCR negative COVID-19 patients with comorbid diseases?

Abstract

Background. The COVID-19 pandemic has affected the whole world and still, sufficient progress has not been made in diagnosis and treatment. Since there has not been a definite method for the treatment of COVID-19 yet, the mortality rate is extremely high despite the different treatments. Mortality rates of COVID-19 in China are reported as 1.4–4.61%, in Italy— 11.9%, in Spain— 9.0%, and in the UK— 7.9%. The study purpose was to investigate the mortality rates in reverse transcriptase-polymerase chain reaction (RT-PCR) negative COVID-19 patients with comorbid the disease. Materials and methods. A retrospective cross-sectional study was conducted in the COVID-19 service. Patients who had COVID-19 treatment in our clinic between March 2020 and March 2021 were included in the study. A review of medical records was performed. Results. Comorbidity rates of the 515 patients were 40.4% hypertension (HT), 16.7% diabetes mellitus, 13% pulmonary diseases, 28% coronary artery disease (CAD), 12.6% psychiatric diseases, 3.7% oncological diseases and 18.4% other diseases. While 40 patients (7.8%) died, 475 patients (92.2%) recovered. Most of the patients who died were found to have a negative PCR test result (30 patients, 75%) and this difference was significant in the statistical analysis based on RT-PCR status (p=0.006). Moreover, evaluating the effects of comorbid diseases on prognosis, it was found that HT (p=0.001), CAD (p=0.004), and asthma and/or chronic obstructive pulmonary disease (p=0.019) were associated with poor prognosis. Conclusions. HT, CAD, and pulmonary diseases are supposed to be associated with poor prognosis. In addition, it is noteworthy that the mortality rates in the RT-PCR negative patient group were higher. Delay in clinic entry and delay in treatment may explain the high mortality rates in patients with negative RT-PCR. Evaluating the symptoms, examining chest CT and hematological data, and establishing treatment plans earlier can reduce mortality in RT-PCR negative patients.