Changes in uroflowmetry indicators with automatic interference elimination

Aim. The aim of this article is to compare the values of measured (Q_MAX) and calculated (Q_MCLC) maximal urine flow and the values of measured (T_Q) and calculated (T_QCLC) time to reach maximal flow in a large group of individual uroflowgrams during home uroflowmetry.

Materials and Methods. We analysed 29,110 individual uroflowgrams from 719 patients with prostate adenoma, aged 50 to 73 years (mean age, 60.5 ± 8.2 years), collected between 2004 and 2024. Two algorithms were used: determination of Q_MAX as the maximum value of the calculated flow (function extremum) and calculation of the actual value of the maximum flow after computer processing to eliminate interference and the WAG-effect (Q_MCLC).

Results. The data showed the following differences between Q_MAX and Q_MCLC in the groups: 16.14 % for volumes up to 100 ml; 14.62 % for 100–200 ml; 13.75 % for 200–300 ml; 13.04 % for 300–400 ml; 14.25 % for 400–500 ml; 14.55 % for 500–600 ml; and 12.65 % for 600+ ml. For T_Q and T_QCLC values, the group differences were as follows: 3.49 % for volumes up to 100 mL; 2.27 % for 100–200 mL; 0.71 % for 200–300 mL; 0.97 % for 300–400 mL; 0.91 % for 400–500 mL; 3.51 % for 500–600 mL; and 1.51 % for 600+ mL.

Conclusion. The study demonstrated a statistically significant difference between the maximum urine flow (Q_MAX) values obtained during measurement and the maximum urine flow value, after removing interference and the WAG effect (Q_MCLS) characteristic of any recorded volumes. Therefore, the accuracy of the data obtained may differ depending on the algorithm of uroflowgram processing. No statistically significant difference was found between T_Q and T_QCLC parameters. The algorithm of uroflowgrams processing used in the Sigma and Urovest uroflowmetry hardware and software system ensures high accuracy in determining maximum flow values; Urovest, in particular, has demonstrated reliability in this regard. The average determined difference between the Q_MAX and Q_MCLC values at different volumes of urination is 14.14 %.

1. Danilov VV, Danilov VV. Neirourologiia. Vladivostok, 2019. Vol. 1. 280 p. (in Russ.).

2. Rollema HJ. Uroflowmetry in males, reference values and clinical application in being prostatic hypertrophy : PhD diss. Geonongen, 1981. 288 p.

3. Addla SK, Marri RR, Daayana SL, Irwin P. Avoid cruising on the uroflowmeter: evaluation of cruising artifact on spinning disc flowmeters in an experimental setup. Neurourol Urodyn. 2010 Sep;29(7):1301—1305. https://doi.org/10.1002/nau.20846

4. Greenland JE, Brading AF. The effect of bladder outflow obstruction on detrusor blood flow changes during the voiding cycle in con-scious pig. The journal of urologe. 2001;165:245—248. https://doi.org/10.1097/00005392-200101000-00072

5. Nitti VW. Practical urodynamics. Philadelphia, 1998. 295 p.

6. Rollema HJ. Uroflowmetry. Clinical neurourology. Edited by R. J. Crane, B. M. Siroky. Boston ; Toronto ; London, 1991. 288 p.

7. Heesakkers J, Farag F, Pantuck A, Moore K, Radziszewski P, Lucas M. Applicability of a disposable home urinary flow measuring device as a diagnostic tool in the management of males with lower urinary tract symptoms. Urol Int. 2012;89(2):166—172. https://doi.org/10.1159/000338907.000338907

8. Long Depaquit T, Michel F, Gaillet S, Savoie PH, Karsenty G. Techniques et intérêt clinique de la débitmétrie à domicile: une revue de la littérature [Home uroflowmetry technics and clinical relevance: A narrative review]. Prog Urol. 2022 Dec;32(17):1531—1542 (in French). https://doi.org/10.1016/j.purol.2022.07.142

9. Serati M, Braga A, Rosier PFWM, de Wachter S, Uren A, Finazzi-Agrò E. Acceptability and perceived value of urodynamics from the patient perspective: A narrative review. Neurourol Urodyn. 2022 Jun;41(5):1065—1073. https://doi.org/10.1002/nau.24932

10. Monger L, Wilkins A, Allen P. Identifying visual stress during a routine eye examination. J Optom. 2015 Apr;8(2):140—145. https://doi.org/10.1016/j.optom.2014.10.001

11. Golomb J, Lindner A, Siegel Y, Korczak D. Variability and circadian changes in home uroflowmetry in patients with benign prostatic hyperplasia compared to normal controls. J Urol. 1992 Apr;147(4):1044—1047. https://doi.org/10.1016/s0022-5347(17)37462-1.S0022-5347(17)37462-1

12. De La Rosette JJ, Witjes WP, Debruyne FM, Kersten P, Wijkstra H. Improved reliability of uroflowmetry investigations: results of a portable home-based uroflowmetry study. Br J Urol. 1996 Sep;78(3):385—390. https://doi.org/10.1046/j.1464-410x.1996.00115.x

13. Boci R, Fall M, Waldén M, Knutson T, Dahlstrand C. Home uroflowmetry: improved accuracy in outflow assessment. Neurourol Urodyn. 1999;18(1):25—32. https://doi.org/10.1002/(sici)1520-6777(1999)18:1<25::aid-nau5>3.0.co;2-o.10.1002/(SICI)1520-6777(1999)18:1<25::AID-NAU5>3.0.CO;2-O

14. Heesakkers J, Farag F, Pantuck A, Moore K, Radziszewski P, Lucas M. Applicability of a disposable home urinary flow measuring device as a diagnostic tool in the management of males with lower urinary tract symptoms. Urol Int. 2012;89(2):166—172. https://doi.org/10.1159/000338907.000338907

15. Gan ZS, Zderic SA. Current state and future considerations for home uroflowmetry. Nat Rev Urol. 2023 Sep;20(9):515—516. https://doi.org/10.1038/s41585-023-00785-4

16. Bladt L, Kashtiara A, Platteau W, De Wachter S, De Win G. First-Year Experience of Managing Urology Patients With Home Uroflowmetry: Descriptive Retrospective Analysis. JMIR Form Res. 2023 Oct 17;7:e51019. https://doi.org/10.2196/51019