[Home uroflowmetry technics and clinical relevance: A narrative review]

Urine flowmetry (UF) is a key non-invasive urodynamic test for the evaluation of the voiding phase in patients with lower urinary tract symptoms (LUTS). Traditional free urodynamic testing (FUT) performed on a one-time basis in the office is limited by difficulty in capturing normal voiding and high intrapatient variability in urine flow parameters. Home measurement of urine flow by the patient could be a way to obtain multiple data in real-life conditions, addressing its limitations. The objective of this article was to review the literature on the different techniques of home uroflowmetry (HUF) and their clinical interest in comparison with FUT.

A search on the PubMed database using the key words "Urodynamics, Uroflowmetry, non-invasive urodynamics, Ambulatory urodynamics, bladder outlet obstruction, male LUTS" was performed to find articles in English or French that had been published with no time limit and March 2022. The sorting by reading the abstract allowed the selection of all articles describing and/or evaluating a HUF technique that were read entirely according to the same collection grid to propose a narrative synthesis.

Thirty-one articles were identified, selected, and analyzed. Simple and inexpensive techniques by timing or use of funnels reliably and reproducibly estimate the average and maximum urine flow in relation to the FUT, without providing a complete flow curve. More sophisticated electronic or sonometric methods, some using connected mobile applications, present results that are more consistent with ICS recommendations for flow measurement. With the possibility of studying the average of several values of the maximum urinary flow (Qmax) captured during micturition in physiological conditions, some studies suggest a gain in diagnostic value in the evaluation of the emptying phase and lower urinary tract symptoms in men. However, the literature is sparse, old and the clinical benefits are not yet proven.

There is a wide range of techniques for measuring urine flow in the patient's home, all of which aim to fill the gaps in conventional urine flow measurement. Further studies are needed to demonstrate the acceptability of this type of measurement by patients, the existence of a real clinical benefit, to assess the cost/benefit balance and finally to define a possible place for home uroflowmetry in daily practice, compared with traditional free flowmetry and invasive urodynamics (pressure-flow test).