2.1 Statistical analyses
Statistical analyses were performed using SPSS software (ver. 21.0; IBM, Chicago, IL, USA). Continuous variables are expressed as medians (minimum–maximum) and categorical variables as values and percentages. Categorical data were compared using chi-square tests. For non-normally distributed data, the Mann–Whitney U test was used to determine whether or not differences between groups were statistically significant. Spearman’s method was used to evaluate correlations between the IPF and other blood parameters if variables were not normally distributed. The most discriminating biomarkers for acute bronchiolitis were identified by drawing receiver operating characteristic (ROC) curves for each biomarker, and calculating sensitivity and specificity, as well as positive and negative predictive values. Areas under the curves (AUCs) for IPF, PLT, MPV, PDW, and white blood cell count (WBC) were evaluated for the acute bronchiolitis versus the control group. Logistic regression was used to identify associated factors and to calculate odds ratios and 95% confidence intervals. A p -value < 0.05 was considered statistically significant.