Predictors of severe and critical COVID-19: A systematic review

BACKGROUND Coronavirus disease 2019(COVID-19) has emerged as a public health crisis that was declared as a global pandemic by the World Health Organization. Although most cases have no or mild symptoms, around 10% of patients develop severe or critical illness that necessitates hospitalization and intensive care unit admission.AIM To assess the literature for the predictive factors that can identify patients having severe/critical COVID-19 disease.METHODS A Preferred Reporting Items for Systematic Reviews and Meta-Analysescompliant systematic search of the literature was conducted. Electronic databases including Pub Med/MEDLINE, Scopus, and Cochrane Library were queried. The main outcome measures were the predictors of severe/critical COVID-19 and mortality.RESULTS Five studies including 583 patients of a median age of 50.5 years were reviewed.Patients were 346(59.4%) male and 237(40.6%) female. Of 583 hospitalized patients, 242(41.5%) had critical illness. Acute respiratory distress disease occurred in 291 patients, accounting for 46.7% of total complications. Onehundred(17.1%) mortalities were recorded. The most commonly reported predictors of severe COVID-19 were older age, medical comorbidities,lymphopenia, elevated C-reactive protein, increased D-dimer, and increased neutrophil ratio. Findings on computed tomography(CT) scanning predictive of severe disease were bronchial wall thickening, CT score > 7, linear opacities,consolidation, right upper lobe affection, and crazy paving pattern.CONCLUSION Several demographic, clinical, laboratory, and radiologic factors can help predict severe and critical COVID-19 along with the potential need for mechanical ventilation. Factors that were more commonly reported were older age, medical comorbidities, lymphopenia, increased neutrophil ratio, elevated C-reactive protein, and increased D-dimer.