Predicting Bladder Outflow Obstruction: A Simplified Score Based on Urethral Pressure Profilometry and Uroflowmetry

Torres Sandoval C1, Ochoa C2, Gammie A2, Thomas L2, Priju S2, Tindle R2, García Perdomo H3, Hashim H2

Research Type

Clinical

Abstract Category

Urodynamics

Abstract 147
Urodynamics
Scientific Podium Short Oral Session 17
Thursday 8th October 2026
14:45 - 14:52
Parallel Hall 4
0.10 Sydney
Capacity: 265
Bladder Outlet Obstruction Urodynamics Techniques Male
1. Pontificia Universidad Javeriana, Bogota, Colombia, 2. Bristol Urological Institute, 3. Universidad del Valle, Cali, Colombia
Presenter
Links

Abstract

Hypothesis / aims of study
To develop a simplified clinical risk score integrating urethral pressure profilometry through the Prostatic Plateau Area (PPA) and maximum flow rate (Qmax) during uroflowmetry to identify men with a high probability of bladder outflow obstruction.
Study design, materials and methods
This original cross-sectional study included men who underwent urodynamics and urethral pressure profilometry (UPP) between July 2022 and October 2025 in a tertiary centre. Patients with neurogenic lower urinary tract dysfunction, or prior prostate or urethral surgery were excluded. Bladder outlflow obstruction was defined according to the Bladder Outlet Obstruction Index (BOOI). A BOOI >40 was used to define obstruction. PPA was calculated as the product of prostatic plateau pressure (PPP) and functional length (FL). FL was defined as the distance from the onset of the urethral pressure profile to the midpoint of the maximum urethral closure pressure (MUCP) peak. Continuous variables (e.g., Age, Qmax, PPA) were summarized according to distribution and compared across BOOI categories using Welch’s-ANOVA and Games–Howell tests, while categorical variables (e.g., BCI categories) were analyzed using Chi-square test. A multivariable logistic regression model was constructed with BOOI >40 as the dependent variable and PPA and Qmax as independent predictors. The events-per-variable ratio was 58.5. A simplified score was derived from the regression coefficients. Discrimination was assessed using the area under the ROC curve. Internal validation was performed using 2000 bootstrap resamples to estimate optimism-corrected discrimination. Model calibration was evaluated using calibration intercept and slope. Risk categories were defined using percentile-based stratification (25th and 75th percentiles) and rounded to practical thresholds. Data was stored in Microsoft Excel and analyzed using Jamovi statistical software (version 2.3.28). Artificial intelligence tools were used to support aspects of data organization and statistical workflow structuring in Jamovi.
Results
A total of 266 men were included, of whom 117 (44%) were classified as obstructed. PPA showed a moderate positive association with BOOI, whereas Qmax demonstrated a moderate inverse association (both p < 0.001). The simplified score (S = PPA − 10×Qmax) achieved an AUC of 0.755, comparable to the multivariable logistic regression model. Internal validation yielded an optimism-corrected AUC of 0.754. Calibration analysis demonstrated good agreement between predicted and observed probabilities (intercept −0.066; slope 0.978). Compared with the low-risk group, the odds of BOO increased across risk categories, reaching OR 3.29 (95% CI 1.6–6.7) and OR 18.1 (95% CI 7.8–42.1) in the intermediate- and high-risk groups, respectively. The high-risk threshold (>85) demonstrated high specificity (89.9%) and positive predictive value (PPV) (78.6%). The low-risk group (≤ −25) included 83.1% of patients without BOO, indicating a low probability of obstruction within this category.
Interpretation of results
The simplified score preserves the discriminative performance of the multivariable logistic model while enabling clinically practical risk stratification. The high-risk threshold prioritizes specificity and PPV, supporting its potential role as a rule-in criterion.
Concluding message
This internally validated score provides clinically meaningful discrimination for identifying patients with BOO. While pressure–flow studies remains the gold standard for diagnosis, this index may serve as a supportive tool in scenarios where an adequate study cannot be obtained, such as in patients inability to void. It is not intended to replace conventional multi-channel urodynamic evaluation, but rather to complement clinical decision-making in selected contexts. Nevertheless, prospective studies and external validation are required before considering its implementation in clinical practice.
Figure 1 Area under the receiver operating characteristic curve. Discriminative Performance of Qmax, PPA, Simplified and logistic Predictive Models for Bladder Outflow Obstruction (BOOI >40)
Figure 2 Percentages are presented as row proportions. Group differences were assessed using chi-square (χ²(2) = 55.9, p < 0.001). OR and 95%CIs were calculated using the low-risk group as the reference.
Disclosures
Funding No grants or external funding to declare Clinical Trial No Subjects Human Ethics Committee Ethical approval to use database for research purposes. Additionally, all patients provided informed consent for the use of their data. Helsinki Yes Informed Consent Yes AI Other AI Usage Artificial intelligence tools were used to support data organization in Excel and the structuring of statistical workflows in Jamovi, as well as to assist with text editing and image preparation.
Citation

Continence 19S (2026) 102624
DOI: 10.1016/j.cont.2026.102624

31/10/2026 21:52:39