Methods of competing risks analysis of time to occurrence of reflux among children with antenatal hydronephrosis

We aimed to describe a standard survival analysis, so that we can analyze some factors related to the time of occurrence of different types of reflux (unilateral-left, unilateralright, and bilateral) in children with antenatal hydronephrosis (ANH) and to provide an approach taking competing risks into account.
Methods & Materials: We used data of 193 children that was collected from Pediatric Urology Research Center of Children’s Hospital Medical Center, affiliated to Tehran University of Medical Sciences, Iran. The cause-specific and subdistribution hazard were computed. P Among these infants (36 girls, 157 boys), 117 (68%) cases had bilateral reflux as the event of interest. The variables “Sex” and “Direction of ANH (in bilateral level)” were significantly different (P In the competing risks framework, it is inappropriate to use the Cox and Kaplan-Meier methods, which do not take competing risks into account. Multivariate regression model like the subdistribution hazard model besides the cumulative incidence curve are recommended.