Demographic and clinical characteristics associated with LBAI
A total of 440 patients with COVID-19 were included in the final analysis. The median age was 63 years (IQR 18) and 233 (53%) were female. Median follow-up time was 17 days (IQR 21). The total incidence rate of cumulative LBAI was 57.7%, including 15.7% with ALI. The different incidence rates of cumulative LBAI stratified by sociodemographic and clinical characteristics were shown in table 1. The likelihood of cumulative LBAI increased with age of patients, with a 2-fold risk in patients aged ≥65 years compared with those aged 50 years or younger (OR 1.83; 95% CI 1.03 to 3.26). Female patients were at higher risk of cumulative LBAI (OR 2.09; 95% CI 1.46 to 3.06) than males.
Additional significant associated risk factors with LBAI included comorbidities, especially diabetes, vital signs on admission (including temperature, respiratory rate, pulse oximeter O2 saturation, and heart rate), and severity of illness (qSOFA and CURB-65 scores). Compared to general COVID-19 patients, LBAI occurred more often in severe and critical patients with 2-fold (OR 2.86; 95% CI 1.78 to 4.59) and 13-fold (OR 13.44; 95% CI 7.21 to 25.07) higher likelihood, respectively.