Frequency of underlying diseases, symptoms and mortality rate of COVID-19: a systematic review and meta-analysis

Coronavirus disease 2019 (COVID-19) is known to be affected by underlying diseases of the respiratory system. In this meta-analysis, the keywords of COVID-19, underlying diseases, symptoms, and mortality were searched in national and international databases to obtain the related studies. The inclusion criteria were as follows: interventional, clinical, descriptive and cross-sectional, and studies focusing on COVID-19. This study was conducted based on Preferred Reporting Items for Systematic Reviews and MetaAnalyses protocol. Eighteen studies were selected to be finally analyzed. The mean percentage of mortality was 14 (I-2 = 98.9, P< 0.001). The most common symptoms were fever (91, I-2 = 88.5, P< 0.001) and cough (71, I-2= 84.5, P< 0.001), and the most frequent underlying diseases were hypertension (41, I-2 = 98.9, P<0.001), diabetes mellitus (18, I-2 = 88.7, P< 0.001) and cardiovascular disease (11, I-2 = 87.7, P< 0.001). Findings of present study suggest that individuals with underlying diseases have a higher rate of mortality following COVID-19 infection. Copyright (C) 2021 Wolters Kluwer Health, Inc. All rights reserved