Free Uroflowmetry versus Pressure-flow Study in the Diagnosis of an Overactive Bladder Syndrome in Female Patients

Hypothesis / aims of study Recently, the Flow Index (FI) was proposed as overactive bladder (OAB) urodynamic objective marker. It is calculated as a division of average urethral flow rate to maximal urethral flow rate. Interestingly, no linear and nonlinear correlation between micturition volume and FI was found. When using Receiver Operating Characteristic (ROC) the area under the curve (AUC) for FI was as high as 0.722, which clearly indicates that it is a good parameter which allows distinguishing between the OAB group from the rest of the patients. The cut-off point of FI value was 0.47 with sensitivity, and specificity at 69.8% and 69.9%, respectively [1]. The diagnosis of OAB is mostly based on patients’ symptoms and bladder diary, but the objective tool for diagnosis confirmation is still needed. As there is evidence that the results of free uroflowmetry and pressure-flow study (PFS) do not differ it may appear that the utility of these studies in the diagnosis of OAB, with additional marker – Flow Index is similar.[2] The aim of current study was to determine if the PFS parameters, including FI, could increase the accuracy of urodynamic study (UDS) in the diagnosis of OAB syndrome.