Non-invasive diagnosis of bladder instability using the Bladder Instability Discriminant Index (BIDI).

The purpose of this study was to validate prospectively the BIDI index in the non-invasive diagnosis of bladder instability, as a procedure for clinical evaluation in primary health care of women. 217 patients were studied; 82 with stress incontinence, 39 with urge incontinence and 96 with both symptoms. All patients were studied by specialist physicians, who conducted a clinical evaluation, questionnaire, gynecological and urological examination, stress test, urodynamic assessment and a 7 day frequency/volume study, recording each intake and micturition; data that were used to calculate the BIDI index. The results obtained through the application of the BIDI were compared with the corresponding urodynamic diagnoses, achieving 88% sensitivity and 83% specificity. The use of the BIDI index is suggested as a non-invasive clinical diagnostic method, of low cost and simple performance. It is recommended for treatment control and for taking diagnostic and therapeutic decisions in medical centres lacking proper urodynamic equipment.