Results
Figure 1 shows the PRISMA flow diagram for selection of studies. A total of 32 studies were included; one multicentered randomized controlled trial, seven case-control studies and the remaining were observational studies. Results of the quality assessment of included articles are shown in Table 1. The studies included a total number of 3,924 patients. Five studies evaluated only adult population4-8; ten studies were on paediatric population (defined as under 18 years)9-18; ten studies included both adult and children19-28; eight studies did not report on the participants’ age 29-36.