Global Prevalence of Comorbidities and Disease Severity and Mortality in Association With Geographic Region, Gender, Age and Smoking Status in Patients With COVID-19: A Systematic Review, Meta-Analysis and Meta-Regression

Background and Aims: A COVID-19 patient often presents with multiple comorbidities and is associated with adverse outcomes. A comprehensive assessment of the prevalence of comorbidities in patients with COVID-19 is important. This study aimed to assess the prevalence of comorbidities, severity and mortality with regard to geographic region, age and gender in patients with COVID-19.Method: A systematic review and multistage meta-analyses were reported using PRISMA guidelines. PubMed/MEDLINE, SCOPUS, Google Scholar and EMBASE were searched from January 2020 to July 2021. Cross-sectional studies, cohort studies, case series studies, and case-control studies on comorbidities reporting among the COVID-19 populations that were published in English were included. The pooled prevalence of various medical conditions in COVID-19 patients was calculated based on regional population size weights. Stratified analyses were performed to understand the variations in the medical conditions based on age, gender, and geographic region.Results: A total of 190 studies comprising 105 million COVID-19 patients were included. The pooled prevalence of medical comorbidities: hypertension (39%, 95% CI: 36–42, n=170 studies), obesity (27%, 95% CI: 25–30%, n=169 studies), diabetes (27%, 95% CI: 25–30%, n=175), and asthma (8%, 95% CI: 7–9%, n = 112). Moreover, the prevalence of hospitalization was 35% (95% CI: 29–41%, n = 61), intensive care admissions 17%(95%CI:14–21, n=106), and mortality 18% (95% CI: 16–21%, n=145). The prevalence of hypertension is higher in Europe 44%(95% CI: 39–47%, n=68), both obesity 30% (95%CI, 26-34, n=79) and diabetes 27% (95%CI, 24-30, n=80) in North America and asthma in Europe 9% (95%CI, 8 -11, n=41). Obesity is higher among aged ≥50 years (30%, n=112), diabetes among men (26%, n=124), and observational studies reported higher mortality than case-control studies (19% vs. 14%).Conclusion: A higher prevalence of hypertension (39%) and mortality was 18% in the COVID-19 patients. Accelerating the COVID-19 vaccination in patients with chronic comorbidities to prevent COVID-19 hospitalization and mortality.Funding Information: None to declare.Declaration of Interests: None to declare.