A comparison of Schaefer, International Continence Society and bladder contractility index nomograms in the diagnosis of obstruction and detrusor underactivity in men with lower urinary tract symptoms

Rubilotta E1, Balzarro M1, Trabacchin N1, Bassi S1, D'Amico A1, Cerruto M A1, Artibani W1

Research Type


Abstract Category


Abstract 102
Open Discussion ePosters
Scientific Open Discussion ePoster Session 7
Wednesday 29th August 2018
12:25 - 12:30 (ePoster Station 4)
Exhibition Hall
Detrusor Hypocontractility Male Bladder Outlet Obstruction Underactive Bladder Urodynamics Techniques
1. Dept. of Urology, AOUI Verona, Italy

Emanuele Rubilotta




Hypothesis / aims of study
Aim of the study was to evaluate the correspondence between Schaefer nomograms (Sn), and both International Continence Society nomogram (ICSn) and Bladder Contractility Index (BCI).
Study design, materials and methods
From January 2012 to October 2017, we collected data on 458 men underwent Flow-Pressure study for lower urinary tract symptoms. All urodynamics (UD) were performed according to Good Urodynamic Practice1 and analyzed with Sn, ICSn and BCI. Bladder outlet obstruction (BOO) was defined as Sn obstruction classes ranging from III to VI, and ICSn score <40. Detrusor underactivity (DU) was considered as Sn contractility classes Weak (W)/Very Weak (VW), and BCI score <100.
Among unobstructed patients the concordance between the 2 nomograms was 97.4%. There was a complete concordance of un-obstruction only in Sn class 0, while in class I the concordance reached 70%. Among patients with equivocal diagnosis at ICSn, the Sn class II was the most usual (67.2%). Among patients clearly obstructed at ICSn, there was a complete concordance between the 2 nomograms. Moreover, 74.4% of the patients were in Sn classes III-IV, and 22.4% in classes V-VI. Table 1 resumes data regarding BOO.
We found a high correspondence in patients with normal detrusor contractility between the 2 nomograms (96.7%). In case of DU at BCI we found that 96.2% of males were in classes W/VW of Sn. Among males with normal detrusor contractility at Sn, 11% had a diagnosis of DU at BCI. Table 2 reports data on DU.
Interpretation of results
We found a high concordance between Schaefer and ICS nomograms. Only Sn class 0 was completely associated to diagnosis of un-obstruction at ICSn. Equivocal diagnosis at ICSn corresponded in most of cases at Sn class II. When ICSn documented obstruction, Sn reached a complete correspondence. Correspondence between Sn and BCI was high (96%), but a relevant number of patients with Sn normal contractility class had a diagnosis of DU at BCI (11%).
Concluding message
Data showed a high correspondence between Sn and ICSn, and most of the equivocal diagnosis at ICSn corresponded to Sn low obstruction (Class II). Correspondence between Sn and BCI was high but surprisingly with a misleading diagnosis in 1/10 patient.
This study evidences how in the clinical practice to achieve a more precise diagnosis of bladder underactivity and/or bladder outlet obstruction it is useful to use all the nomograms.
Figure 1
Figure 2
  1. Schdfer W, Abrams P, Liao L, Mattiasson A, Pesce F, Spangberg A, et al . Good urodynamic practices: Uroflowmetry, filling cystometry, and pressure-flow studies. Neurourol Urodyn 2002;21:261-74.
Funding None Clinical Trial No Subjects Human Ethics Committee Internal Ethics Committee Department of Urology AOUI Verona Helsinki Yes Informed Consent Yes