Deep drop: a common finding in uroflowmetry of healthy children and adolescents

Published: 16 December 2022| Version 1 | DOI: 10.17632/rkz52fv463.1
Stephen Shei-Dei Yang


This database presents the results of our large-scale cross-sectional study of uroflowmetry tests in healthy children and adolescents. A total of 2299 uroflowmetry curves from 1538 children and adolescents aged 5-18 years were analyzed. Based on the results, we proposed comprehensive criteria for defining “deep drop (DD)” and assess the incidence of DD in the uroflowmetry curves of health subjects. Subsequently, we assessed the accordance with the interpretation of DD with an additional 100 randomly selected uroflowmetry curves from the urology clinic. We hope that this set of criteria will help define staccato uroflowmetry pattern and standardize terminology for future research.


Steps to reproduce

Healthy adolescents aged 12–18 years were recruited from kindergartens, primary schools and high schools. The uroflowmetry and ultrasound stations were set up in the medical rooms or disabled restrooms of the schools. To ensure privacy during the tests, we installed privacy curtains, temporary partitions, and cordoned off the test area. Adolescents with neurological disorders, known LUT dysfunction or UTI symptoms were excluded from the study. Participants were reminded to drink water and to perform uroflowmetry test whenever they had the urge to pass urine. Participants were encouraged to perform two uroflowmetry tests (UFM Master 1, MMS, Netherlands). Males voided in the standing position and females in the sitting position with adequate foot support.


Taipei Tzu Chi Hospital


Pediatric Urology


Taipei Tzu Chi Hospital