Reproducibility of uroflowmetry results in patients with benign prostatic hyperplasia
Objective. To assess the reproducibility of the results of uroflowmetry in patients with benign prostate hyperplasia (BPH).
Materials and methods. The reproducibility of uroflowmetry was assessed by calculation of an error in particular Qmax values with respect to description of true mean Qmax. We calculated the volume of the sample of Qmax values required for reliable calculation of mean Qmax. Calculations were made by analysis of 214 uroflowmetry procedures (4499 uroflowmetry nomograms) of 107 patients with BPH before and after pharmacological testing with an alpha1 adrenoceptor blocker.
Results. The reproducibility of the results of single uroflowmetry was very low. A particular Qmax describes a true mean Qmax with an error of ± 14 mL/s. Selection for analysis of Qmax values obtained at volumes above 150 mL leads to increased errors in particular Qmax to ± 22 mL/s. In group studies, 70 uroblowmetry procedures are required in order to obtain significant mean Qmax values before a pharmacological test with alpha1-blockers, after a test – 77.
Conclusion. The low reproducibility of the results of single uroflowmetry is accounted for by a changeability of particular Qmax values conditioned by dysfunction of the autonomic centres that regulate urination. The impossibility to eliminate the error in particular Qmax values by clinically acceptable means is indicative that the potential of standard uroflowmetry for assessment of urination disorders is limited. The dynamics of urination disorders after alpha1-blocker therapy cannot be reliably assessed by comparing particular Qmax values before and after therapy.
Key words: benign prostatic hyperplasia, urination disorders, uroflowmetry, Qmax error, neurophysiological model
For citation: Danilov V.V., Osinkin K.S., Sevryukov F.A. Reproducibility of uroflowmetry results in patients with benign prostatic hyperplasia. Vopr. urol.
androl. (Urology and Andrology). 2019; 7(3): 5–9. (In Russian). DOI: 10.20953/2307-6631-2019-3-5-9