Antimicrobial prophylaxis for vesicoureteral reflux: which subgroups of children benefit the most?

While the Randomized Intervention for Children with Vesicoureteral Reflux (RIVUR) trial found that long-term antimicrobial prophylaxis reduced the risk of urinary tract infection (UTI) recurrences by 50%, 10 children had to be treated for one to benefit (i.e., observed number needed to treat (NNT) of 10). Accordingly, we re-analyzed RIVUR data to systematically identify subgroups of children with vesicoureteral reflux (VUR) with a smaller NNT.

Using patient-level data from the RIVUR trial, we applied penalized regression methods including the baseline age, VUR grade, type of index UTI, and bowel-bladder dysfunction (BBD) as covariates to identify subgroups.

We identified four relevant subgroups of children that appear to benefit from long-term antimicrobial prophylaxis, all with observed NNTs smaller than or equal to 5: children with grade IV VUR, BBD, and febrile index UTI (1% of the sample), children with BBD and febrile index UTI (7% of the sample), children with BBD (12% of the sample), and children with grade IV VUR (8% of the sample).

Use of long-term antimicrobial prophylaxis appears to be particularly relevant for children with BBD (and any grade of VUR) and those with grade IV VUR (regardless of BBD status). However, because details regarding the treatment of BBD are not available, further studies are needed to fully determine the role of prophylactic antimicrobials in the management of children with VUR who have BBD.