Comorbidities and the risk of severe or fatal outcomes associated with coronavirus disease 2019: A systematic review and meta-analysis

Objectives: Existing findings regarding the relationship between comorbidities and the severity of coronavirus disease 2019 (COVID-19) are inconsistent and insufficient. The aim of this study was to evaluate the association between different comorbidities and the severity of COVID-19.

Methods: The PubMed, Embase, and Cochrane Library databases were searched to identify studies reporting the rates of comorbidities in COVID-19 patients with severe/fatal outcomes. Subgroup analyses were conducted according to disease severity and the country of residence. Odds ratios (OR) with 95% confidence intervals (CI) were pooled using random-effects models.

Results: A total of 34 eligible studies were identified. In patients with severe/fatal COVID-19, the most prevalent chronic comorbidities were obesity (42%, 95% CI 34-49%) and hypertension (40%, 95% CI 35-45%), followed by diabetes (17%, 95% CI 15-20%), cardiovascular disease (13%, 95% CI 11-15%), respiratory disease (8%, 95% CI 6-10%), cerebrovascular disease (6%, 95% CI 4-8%), malignancy (4%, 95% CI 3-6%), kidney disease (3%, 95% CI 2-4%), and liver disease (2%, 95% CI 1-3%). In order of the prediction, the pooled ORs of the comorbidities in patients with severe or fatal COVID-19 when compared to patients with non-severe/fatal COVID-19 were as follows: chronic respiratory disease, OR 3.56 (95% CI 2.87-4.41); hypertension, OR 3.17 (95% CI 2.46-4.08); cardiovascular disease, OR 3.13 (95% CI 2.65-3.70); kidney disease, OR 3.02 (95% CI 2.23-4.08); cerebrovascular disease, OR 2.74 (95% CI 1.59-4.74); malignancy, OR 2.73 (95% CI 1.73-4.21); diabetes, OR 2.63 (95% CI 2.08-3.33); and obesity, OR 1.72 (95% CI 1.04-2.85). No correlation was observed between liver disease and COVID-19 aggravation (OR 1.54, 95% CI 0.95-2.49).

Conclusions: Chronic comorbidities, including obesity, hypertension, diabetes, cardiovascular disease, cerebrovascular disease, respiratory disease, kidney disease, and malignancy are clinical risk factors for a severe or fatal outcome associated with COVID-19, with obesity being the most prevalent and respiratory disease being the most strongly predictive. Knowledge of these risk factors could help clinicians better identify and manage the high-risk populations.