Statistical analysis
Data were extracted from the PNIC database. Data was processed and analyzed using STATA 15 (STATA Corporation, College Station, TX, USA). Qualitative data, such as sex, were presented as counts and proportions while quantitative data, like age, were presented as means or medians. T-test or Mann-Whitney U test were used to detect differences in quantitative variables from two groups while Chi-square test or Fisher’s exact test were used to assess association in qualitative variables. The results with p value of <0.05 were considered significant.