Cost-effectiveness of antimicrobial prophylaxis for children in the RIVUR trial

Purpose: We evaluated the cost-effectiveness of antimicrobial prophylaxis to prevent recurrent UTIs in children with vesicoureteral reflux based on the RIVUR trial. Materials and methods: A decision tree model compared strategies of antimicrobial prophylaxis vs. placebo in children with reflux using results from the RIVUR trial. Risk reduction was 50% based on intention to treat analysis. Costs were based on Medicare reimbursement and data in literature. The model incorporated costs of medications, imaging and complications such as pyelonephritis, likelihood of surgery and loss of work. One- and two-way sensitivity analyses were performed evaluating the effect of changing variables on the cost-effectiveness of antibiotic prophylaxis in preventing recurrent UTIs. Results: Mean costs were higher for treatment vs. placebo at $3092 and $2932, respectively, with 12.7 fewer infections per 100 children. One-way sensitivity analyses showed that antibiotics would be cost equivalent if the yearly medical cost was $386, rate of recurrent UTI increased to 32%, antibiotic risk reduction was 63%, or rate of pyelonephritis in the placebo group was 48%. Two-way analyses modifying antibiotic cost, risk reduction of antibiotics and probability of infection showed areas where antibiotics could be more cost-effective than placebo. Conclusions: Antibiotic prophylaxis is associated with marginally higher costs compared with placebo, but significantly fewer infections. A slight decrease in antibiotic cost or increase in recurrent UTIs on placebo may result in prophylaxis being more cost-effective. We recognize that the marginal overall cost in antibiotics may have a substantial impact on the quality of life for the individual patient and family.