Penile Compression Release Index Revisited: Evaluation and Comparison with Other Noninvasive Tools in the Prediction of Bladder Outlet Obstruction in Men with Benign Prostatic Enlargement

Abstract

Aim: To determine the discriminatory power of penile urethral compression-release index (PCRI), clinical prostate score (CLIPS) and bladder outlet obstruction index 2 (BOON2) for the detection of bladder outlet obstruction (BOO), and the associated bladder abnormality in patients with benign prostatic enlargement (BPE). Material and methods: In study was included of 135 patients with proven BPE underwent urodynamic measurement (UDM) and PCR maneuver. PCR Index was calculated following the formula: (Qs-Qss)/Qss x 100(%). CLIPS score was calculated based on non-invasive variables (prostate volume, maximal urinary flow, residual urine and voided volume), while BOON2 was calculated using the formula intravesical prostate protrusion (IPP)-3 x Qmax-0.2 x mean voided volume. UDM results were plotted on Schaefer and URA nomograms. Results: A comparative analysis was made using ROC curves. The area under the curve (AUC) for PCRI is 0.85 (PTP 91.3%), while AUC for CLIPS and BOON2 is 0.8 (PTP 77.6%) and 0.82 (PTP 74.5%), respectively. PCRI with the cut-off point of 96% clearly distinguishes obstructed patients with normocontractile detrusor and the presence of detrusor overactivity (DO), versus those unobstructed. CLIPS (>10) shows good BOO prediction, but without the possibility of distinguishing between detrusor contractility grade and the occurrence of DO. BOON2 has shown that impaired contractility has influence on this number in obstructed patients. Conclusion: PCRI is a very good noninvasive urodynamic test for a group-wise detection of BOO in patients with BPE and associated bladder co-morbidities; it is therefore superior in comparison with to CLIPS or BOON2.

Reliability and validity of assessment methods available in primary care for bladder outlet obstruction and benign prostatic obstruction in men with lower urinary tract symptoms: a systematic review

“…The method of manual penile compression by the patient to interrupt the flow midstream was analysed by one study. 23 This manoeuvre was performed while voiding in a uroflowmetry device. An index was created based on two points from the recorded flow.…”

“…With a cut-off index value of 96.4%, BOO based on Schäfer’s obstruction grade could be predicted with a moderate sensitivity of 74% and good specificity of 94%. 23 The level of evidence was graded as moderate for the validity of using a penile compression manoeuvre to indicate BOO, based on a good COSMIN score for criterion validity from a single study with a sufficient sample size (n=135). No measures of reliability were reported for this method (see table 5 ).…”

“…Then, full-text screening was performed for 152 studies, of which 61 studies met all selection criteria and were scored using the COSMIN checklist. Subsequently, 37 studies received a COSMIN score of fair, good or excellent 21–57. Twenty-four studies58–81 received ‘poor’ COSMIN scores and were therefore excluded from the best evidence synthesis.…”

“…Twenty studies evaluated the assessment methods for BOO. The reference tests were BOO-related measures (eg, obstruction grade number or maximum urine flow rate), rather than reference tests for prostate size 22–25 28 29 34 35 37–39 41 44 47 50 51 55–57. An overview of the COSMIN scores per study on BOO is provided in table 3.…”

“…The COSMIN describes criterion validity as the degree to which the scores of an instrument are an adequate reflection of a ‘gold standard’ 85. In the evaluation of BOO, urodynamic studies were often used to calculate a BOO Index (or: Abram-Griffiths number), Schäfer’s obstruction grade or International Continence Society nomogram to define obstruction 22–25 29 34 35 37 38 47 48 50 51 55–57. However, an overestimation or underestimation of the diagnostic accuracy could be present.…”