Development and validation of a clinical nomogram predicting bladder outlet obstruction via routine clinical parameters in men with refractory nonneurogenic lower urinary tract symptoms

We aimed to develop and validate a clinical nomogram predicting bladder outlet obstruction(BOO)solely using routine clinical parameters in men with refractory nonneurogenic lower urinary tract symptoms(LUTS).A total of 750 eligible patient ≥50 years of age who had previously not responded(International Prostate Symptom Score[IPSS]improvement<4 points)to at least three different kinds of LUTS medications(including a-blocker)for the last 6 months were evaluated as subcohorts for nomogram development(n=570)and for split-sample validation(n=180).BOO was defined as Abrams-Griffiths number^40,or 20-39.9 with a slope of linear passive urethral resistance ratio>2 cmH20 ml^-1 s^-1.A stepwise multivariable logistic regression analysis was conducted to determine the predictors of BOO,and^-coefficients of the final model were selected to create a clinical nomogram.The final multivariable logistic regression model showed that age,IPSS,maximum urinary flow rate,postvoid residual volume,total prostate volume,and transitional zone index were significant for predicting BOO;these candidates were used to develop the final nomogram.The discrimination performance of the nomogram was 88.3%(95%Cl:82.7%-93.0%,P<0.001),and the nomogram was reasonably we 11-fitted to the ideal line of the calibration plot.Independe nt split-sample validation revealed 80.9%(95%Cl:75.5%-84.4%,P<0.001)accuracy.The proposed BOO nomogram based solely on routine clinical parameters was accurate and validated properly.This nomogram may be useful in determining further treatment,primarily focused on prostatic surgery for BOO,without impeding the detection of possible BOO in men with LUTS that is refractory to empirical medications.

Does prostate-specific antigen (PSA)mass or free PSA mass improve the accuracy of predicting total prostate volume in relation to obesity in men with biopsy-proven benign prostatic hyperplasia?

We evaluated whether the prostate-specific antigen (PSA)mass or free PSA (fPSA)mass (i.e.,absolute amount of total circulating PSA or fPSA protein,respectively),versus serum PSA or fPSA concentration,improves the accuracy of predicting the total prostate volume (TPV)in relation to obesity.Among men whose multicore (≥12)transrectal prostate biopsy was negative,586 who had a PSA of <10 ng ml^-1 and underwent the fPSA test prior to biopsy were enrolled.The PSA mass or fPSA mass (pg)was calculated by multiplying the serum level by plasma volume.At each TPV cut-off point (30 ml,40 ml,and 50 ml),the areas under the receiver operating characteristics curve (AUCs)of each variable were compared in obesity-based subgroups.AUCs of fPSA and fPSA mass for predicting TPV were significantly larger than those for PSA and PSA mass by 8.7%-12.1%at all cut-off points. Subgroup analyses based on obesity showed that,although PSA mass and fPSA mass enhanced accuracy by 4%(P =0.031)and 1.8%(P =0.003),respectively,for determining TPVs of ≥30 ml and ≥50 ml in obese and overweight men,they did not improve the accuracy in most other combinations of the degrees of obesity with TPV cut-off points.Thus,compared with serum PSA or fPSA,the absolute amount of PSA or fPSA protein mass improved the accuracy of predicting TPV in obese men very minimally and only for certain TPV cut-off points.Hence,these indicators may not provide clinically meaningful improvement in predicting TPV in obese men.