Development and Validation of Symptom Score for Total Bladder-Bowel Dysfunction; Subscales for Overactive Bladder and Dysfunctional Voiding.

PURPOSE Bladder-bowel questionnaires (BBQ) are an important tool in diagnosing non-neurogenic bladder-bowel dysfunction (BBD) in children. In this study, we report the validity and reliability of a BBQ, which has been in clinical use in our institution for decades. MATERIAL AND METHODS The BBQ contains 13 questions with answers ranging from never (0) to daily3. It was answered by 139 healthy controls and 134 children aged 3-16 years diagnosed with BBD by a pediatric urologist/urotherapist. A sub-diagnosis, of overactive bladder (OAB) or dysfunctional voiding (DV), was given each patient. BBQ scales were developed and evaluated against hypotheses of validity (known-groups/convergent/discriminating) and reliability (internal consistency/retest reliability), sensitivity and specificity. Responsiveness was tested in 80 patients who answered the BBQ after treatment. RESULTS A total BBD score scale demonstrated ability to discriminate between patients with a BBD and healthy subjects. It resulted in a ROC curve with AUC 0.96. The maximized sensitivity was 94% and specificity was 89% for a cut-off score of 7. Two subscales were identified referring to six filling-phase items and three voiding-phase items. When tested in OAB and DV patients respectively, multivariable scales performed sufficiently to discriminate between OAB vs non-OAB patients and DV vs non-DV patients. All these scales fulfilled the evaluated requirements for validity and reliability. One year after treatment, all scales scores corresponded to patients' improvement (p<0.0001), suggesting the BBQ can detect clinical change over time. CONCLUSION The BBQ is valid and reliable for diagnosing BBD in pediatric patients, and OAB and DV in those with BBD.