Comparison of patients' assessment of urinary flow strength with uroflowmetry

The objective of the study was to compare patients' self-assessment of urinary flow strength with uroflowmetry.

The study was set in the routine uroflow clinic of the urology department. All patients had symptoms of bladder outlet obstruction. They answered 2 questions and a multiple-choice pictorial representation of flow trajectory. Patients were encouraged to provide 3 flows with at least one volume over 150 ml. The maximum flow rate Qmax was compared with the subjective evaluations.

Qmax was normally distributed. Answers to the questions did separate patients significantly (p < 0.001). However, overlap between groups was large; the group who answered that their flow was poor included many false positives. Pictorial assessment showed low correlation with Qmax, again with a high false-positive rate.

Patients' self-assessment of strength of stream is unreliable as a measure of Qmax and therefore of obstruction. Resection of prostate on history alone is not recommended.