Comorbidity
In 7 eligible trials[15-17, 19, 22-24], hypertension was noted in 166 of 497 patients in Severe group (33.4%) and 151 of 973 in Non-severe group (15.5 %). With pooled OR of 2.30 (95 % CI: 1.35 to 3.92), it was demonstrated that patients with hypertension were associated with significantly increased risk of severe Covid-19 (P=0.002). Consistently, with pooled OR of 2.62 for diabetes (95%CI: 1.27 to 5.44, P=0.009), 4.02 for heart disease (95%CI: 2.08 to 7.77, P<0.0001) and 4.20 for chronic obstructive pulmonary disease (95%CI: 1.61 to 10.95, P=0.003), it was revealed that patients with diabetes[15-17, 19, 22-24], heart disease[15-17, 19, 22-24] and chronic obstructive pulmonary disease[15, 17, 22, 24, 27] were more susceptible to severe Covid-19. Conversely, with pooled OR of 1.81 for cerebrovascular disease (95%CI: 0.56 to 5.84, P=0.32), 1.28 for chronic live disease (95%CI: 0.60 to 2.71, P=0.53), 2.12 for chronic kidney disease (95%CI: 0.80 to 5.61, P=0.13) and 2.69 for tuberculosis (95%CI: 0.66 to 10.97, P=0.17), it was demonstrated that patients with cerebrovascular disease[17, 25], chronic live disease[17, 19, 24, 27], chronic kidney disease[17, 19, 24, 27] and tuberculosis[17, 25] were not associated with increased risk of severe Covid-19. What’s more, smoke[17, 19, 22, 24] did not statistically increased risk of severe Covid-19 (OR: 1.07, 95%CI: 0.40 to 2.85, P=0.90).
Overall, 4 trials reported any comorbidity[17, 21, 22, 24] with 226 of 398 patients in Severe group (56.8%) and 137 of 430 in Non-severe group (31.9%). With pooled OR of 3.61 (95% CI: 1.62 to 8.01), it was revealed that individuals with comorbidity were more susceptible to severe Covid-19 (P=0.002). The outcome was explicitly expressed in Table 2.