A pilot study: a new non-invasive method that differential diagnosis of under active bladder

Introduction
We have tried to define any criteria between under active bladder (UB) and bladder outlet obstruction (BO) from voiding efficiency (VE) without using pressure flow studies.

Material and methods
In male patients uroflowmetry data, post-void residual (PVR) urine data and subsequent pressure flow studies (PFS) were examined retrospectively. Bladder outlet obstruction index (BOI) and bladder contractility index (BCI) were calculated using patients’ PFS values. Patients with BCI < 100 and BOI < 20 were grouped as the UB group and BCI > 100 and BOI > 40 with obstruction were grouped as the BO group.

Results
Forty-four patients in UB and 49 in BO groups, totally 93 patients were examined. According to Qmax value there is no statistically significant difference between the two groups (p = 0.38). Average VE was 63.6 ±2.43% and 46.2 ±2.63% for UB and BO groups, respectively, and the difference was statistically significant (p < 0.001). UB can be diagnosed with at least 95% sensitivity and 88% specificity in men.

Conclusions
Non-invasive uroflowmetry and VE measurements were also shown to differentiate between UB and BO patients, presenting with identical clinic data, besides PFS.