How randomised trials have improved the care of children with kidney disease.

Randomised controlled trials (RCTs) provide the most reliable way to evaluate the benefits and harms of interventions. Participants are divided into groups using methods that balance the characteristics (both known and unknown) of the participants between treatment groups; thus, differences in outcomes are due to the interventions administered. From Cochrane Kidney and Transplant's Specialised Register, a comprehensive registry of trials in kidney disease, we identified 482 trials involving children. The vast majority concerned urinary tract infection (UTI; 134) and nephrotic syndrome (136). Most were small, with a median enrolment of 46 children, with only 26 trials enrolling 200 or more participants, and of these, 18 involved children with UTI. We discuss a number of important advances in the care of children with UTI with or without vesico-ureteric reflux, nephrotic syndrome, chronic kidney disease (CKD) and kidney transplantation that have been driven largely by trials in these conditions.