Factors Associated with COVID-19 Morbidity and Mortality: A Narrative Review

Coronavirus disease 2019 (COVID-19) is an infectious disease caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). It has been declared as a pandemic on March 11th 2020 by the WHO. Morbidity and mortality of COVID-19 has been shown to be high among patients with underlying diseases. In this narrative review, searching a number of electronic databases (PubMed, Google Scholar, Scopus, and Science Direct), 127 related articles written in English were retrieved and of which 73 articles related to risk factors affecting morbidity and mortality of COVID-19 were extracted and summarized. Factors such as old age, male gender and working in health setting were associated with higher morbidity and mortality. Hypertension was the most frequent reported condition among those with severe disease. It also appeared to increase the mortality and duration of hospitalization. Diabetes, respiratory chronic illnesses (COPD, asthma), impaired liver and renal function, and malignancies were also mentioned as the risk factors for severe disease, longer hospitalization, poor prognosis and outcome. Some laboratory findings such as elevated D-dimer, CRP, and LDH as well as severe lymphopenia were associated with severity, mortality and poor outcomes in hospitalized patients. All in all, a considerable number of comorbidities and biomarkers are associated with severity and presentations of COVID-19 disease, affecting its morbidity and mortality rates.