Document Type: SYSTEMATIC REVIEW
Orthopedic Research Center, Mashhad University of Medical Sciences, Mashhad, Iran
Department of Surgery, McGill University, Canada
Background: In this study, we aimed to assess the prevalence of comorbidities in the confirmed COVID-19 patients. This
might help showing which comorbidity might pose the patients at risk of more severe symptoms.
Methods: We searched all relevant databases on April 7th, 2020 using the keywords (“novel coronavirus” OR COVID-19
OR SARS-CoV-2 OR Coronavirus) AND (comorbidities OR clinical characteristics OR epidemiologic*). We reviewed 33
papers’ full text out of 1053 papers. There were 32 papers from China and 1 from Taiwan. There was no language or
study level limit. Prevalence of comorbidities including hypertension, diabetes mellitus, cardiovascular disease, chronic
lung disease, chronic kidney disease, malignancies, cerebrovascular diseases, chronic liver disease and smoking were
extracted to measure the pooled estimates. We used OpenMeta and used random-effect model to do a single arm
Results: The mean age of the diagnosed patients was 51 years. The male to female ratio was 55 to 45. The most
prevalent finding in the confirmed COVID-19 patients was hypertension, which was found in 1/5 of the patients (21%).
Other most prevalent finding was diabetes mellitus (DM) in 11%, cerebrovascular disease in 2.4%, cardiovascular
disease in 5.8%, chronic kidney disease in 3.6%, chronic liver disease in 2.9%, chronic pulmonary disease in 2.0%,
malignancy in 2.7%, and smoking in 8.7% of the patients.
Conclusion: COVID-19 infection seems to be affecting every race, sex, age, irrespective of health status. The risk of
symptomatic and severe disease might be higher due to the higher age which is usually accompanied with comorbidities.
However, comorbidities do not seem to be the prerequisite for symptomatic and severe COVID-19 infection, except
Level of evidence: IV