3.3-Potential risk factors
We showed that old age (aOR, 0.98; 95% CI, 0.97-0.99) reduced severe disease risk after the confounders adjusted. Children with higher weight-for-height SDS were significantly associated with mild disease (aOR, 0.89; 95% CI, 0.84-0.96). Moreover, prematurity, history of atopy, exposure to tobacco smoke, underlying condition, neutrophilia, lymphopenia, and high CRP value were independent risks for severe disease (Table 1).