Statistical analysis
Summary statistics were presented as median with interquartile range (IQR) or percentage where appropriate. Wilcoxon rank sum test or Pearson Chi-square test were used to compare variables between wheezing and non-wheezing patients. The 14 tests were Bonferroni-corrected and interpreted based on Type I error rate of α=0.0036. To assess the association between demographic and clinical characteristics, and viruses with the primary outcome of interest (i.e., wheezing), multivariable logistic regression was used to determine the odds ratios (OR) for wheezing across a-priori selected predictors of interest, including: age, sex, smoke exposure, breastfeeding history, birthweight, type of delivery, prematurity, personal, mother and family history of asthma, and virus type. All analyses had a significance level of 0.05 (two-tailed) and were performed using StataCorp, College Station, TX software (version 15.1).