Manual versus computer methods for diagnosing obstruction from pressure-flow tracings in patients with benign prostatic hyperplasia

Purpose: We compared manual versus computer analysis of pressure-flow tracings for diagnosing bladder outlet obstruction in patients with benign prostatic hyperplasia. Materials and Methods: A total of 105 patients with a clinical diagnosis of prostate enlargement and lower urinary tract symptoms was included in the study irrespective of free flow rates. Pressure-flow studies were performed in duplicate and tracings were evaluated by 2 independent investigators blinded to patient status. Manual reading of urodynamic printouts and fully computerized analysis using CLIM* software were done. All urodynamic parameters relevant to the diagnosis of outlet obstruction were compared using the Abrams-Griffiths and Schafer nomograms. Group specific urethral resistance factors were also compared. Results: There was good correlation between manual and computer derived values of maximum flow (r = 0.9874, p less than or equal to 0.0001), detrusor pressure at maximum flow (r = 0.9943, p less than or equal to 0.0001), minimum detrusor pressure during voiding (r = 0.8816, p less than or equal to 0.0001) and group specific urethral resistance factor (r = 0.9917, p less than or equal to 0.0001). The diagnosis of outlet obstruction according to the group specific urethral resistance factor, and the Abrams-Griffiths and Schafer nomograms was highly consistent using the manual and computerized approaches. Conclusions: Manual analysis of pressure-flow tracings generated by urodynamic equipment and digital data obtained by CLIM software appeared to be highly consistent and equally reliable for diagnosing and grading outlet obstruction.