Statistical analysis
All statistical calculations were performed using Graphpad Prism 7 software. The paired t test was used to evaluate the statistical significance of differences in lung function index before and after atomization. Categorical variables were compared using the Chi-squared test. Risk factors for abnormal lung function were analyzed by multivariate logistic regression, and the OR value and 95% confidence interval (CI) for each risk factor were calculated. P-values < 0.05 was considered to be statistically significant.