The immediate and 6-mo reproducibility of pressure-flow studies in men with benign prostatic enlargement

Urodynamics is an objective method of diagnosing bladder outlet obstruction (BOO) in men. This study examined the immediate and 6-mo reproducibility of this investigation.

Urodynamics was performed in men as part of a multinational, multicentre, double-blind, placebo-controlled drug trial. Each patient had two fill/void cycles both at baseline and 6 mo. The BOO index (BOOI) and bladder contractility index (BCI) were calculated for each cycle and data analysed to look for changes in immediate and 6-mo reproducibility between the two fill/void cycles.

A total of 114 patients had urodynamics at baseline. In the immediate term, although there was a small but statistical fall in both the BOOI and BCI, with cycle one figures greater than those in cycle two, 81% and 79% of patients remained in the same BOOI and BCI category, respectively. At 6 mo, the differences were not statistically different with 70% of patients remaining unchanged in their BOOI category in cycle one and 71% in cycle two; 65% remained unchanged in their BCI category in cycle one and 74% in cycle two. No patient with a BOOI > 65 changed category in the second investigation, and only 5 of 103 first cycles with a BOOI > or = 50 changed category to equivocal obstruction.

Urodynamics has good reproducibility when looking at the BOOI and BCI, indicating that a second study is not necessary in most patients and one investigation is sufficient for an accurate diagnosis on which treatment options can be based.