Effectiveness of percutaneous vesico-amniotic shunting in congenital lower urinary tract obstruction: divergence in prior beliefs among specialist groups.

OBJECTIVE: To explore the prior beliefs regarding the effectiveness of percutaneous vesico-amniotic shunting in congenital lower urinary tract obstruction among different clinical specialist groups involved in caring for this condition. STUDY DESIGN: Questionnaire survey of experts in the field based on principles of Bayesian elicitation of prior beliefs. The sample was 59 consultants in three specialties. Of these, 37 (63%) were subspecialty trained fetal medicine practitioners, 16 (27%) were paediatric nephrologists and 6 (10%) were paediatric urologists. The questionnaire elicited experts' opinions as to: control arm perinatal mortality, effect of vesico-amniotic shunting on perinatal mortality, current clinical practice and the level of evidence required to change current practice. RESULTS: The response rates were 28% for fetal medicine specialists, 29% for paediatric nephrolgists and 10% for paediatric urologists. The median belief for fetal medicine specialists was a 10% (inter-quartile range, IQR 0-20%) reduction in perinatal mortality with shunting and a mean control arm perinatal mortality of 61%. For paediatric nephrologists the results were 5% (IQR -10 to 15%) and 18% and for paediatric urologists 10% (IQR 0-15%) and 17%. Fetal medicine specialists had the most optimistic beliefs regarding effect of shunting on perinatal mortality. Thirty-eight experts (68%) indicated that vesico-amniotic shunting would most likely reduce morbidity associated with renal dysfunction. CONCLUSION: The prior beliefs show a divergence of opinion among specialists. This establishes clinical equipoise, which should be resolved with a randomised trial.