TY - JOUR
T1 - Development of Nomograms to Predict the Recovery of Erectile Function Following Radical Prostatectomy
AU - Mulhall, John P.
AU - Kattan, Michael W.
AU - Bennett, Nelson E.
AU - Stasi, Jason
AU - Nascimento, Bruno
AU - Eastham, James
AU - Guillonneau, Bertrand
AU - Scardino, Peter T.
N1 - Funding Information:
A series of nomograms were constructed using multivariable ordinal logistic regression models. Both ordinal and continuous variables were fit using restricted cubic splines to relax linearity assumptions. No variable selection was performed, because we included all clinically relevant variables. All nomograms were internally validated, with bootstrapping used to correct for optimism. Predictive accuracy of the nomograms was evaluated by 2 methods. First, discrimination was calculated by the area under the receiver operating characteristic curve, with values ranging from 0.5 (no discrimination) to 1 (perfect discrimination). Second, calibration was assessed visually by plotting the nomogram-predicted probabilities against the observed event proportion over a series of equally spaced values within the range of the predicted probabilities. All analyses were performed using S-plus 2000 Professional software (Statistical Sciences, Seattle, WA, USA) or the open source software R (R Development Core Team, 2008) with the Design and Hmisc libraries added.15 This research was funded in part through the NIH/NCI Cancer Center Support Grant P30 CA008748.
Funding Information:
A series of nomograms were constructed using multivariable ordinal logistic regression models. Both ordinal and continuous variables were fit using restricted cubic splines to relax linearity assumptions. No variable selection was performed, because we included all clinically relevant variables. All nomograms were internally validated, with bootstrapping used to correct for optimism. Predictive accuracy of the nomograms was evaluated by 2 methods. First, discrimination was calculated by the area under the receiver operating characteristic curve, with values ranging from 0.5 (no discrimination) to 1 (perfect discrimination). Second, calibration was assessed visually by plotting the nomogram-predicted probabilities against the observed event proportion over a series of equally spaced values within the range of the predicted probabilities. All analyses were performed using S-plus 2000 Professional software (Statistical Sciences, Seattle, WA, USA) or the open source software R (R Development Core Team, 2008) with the Design and Hmisc libraries added. 15 This research was funded in part through the NIH / NCI Cancer Center Support Grant P30 CA008748 .
Publisher Copyright:
© 2019 International Society for Sexual Medicine
PY - 2019/11
Y1 - 2019/11
N2 - Introduction: Given the number of confounders in predicting erectile function recovery after radical prostatectomy (RP), a nomogram predicting the chance to be functional after RP would be useful to patients’ and clinicians’ discussions. Aim: To develop preoperative and postoperative nomograms to aid in the prediction of erectile function recovery after RP. Main Outcome Measures: International Index of Erectile Function (IIEF) erectile function domain score-based erectile function. Methods: A prospective quality-of-life database was used to develop a series of nomograms using multivariable ordinal logistic regression models. Standard preoperative and postoperative factors were included. Main Outcome Measures: The nomograms predicted the probability of recovering functional erections (erectile function domain scores ≥24) and severe erectile dysfunction (≤10) 2 years after RP. Results: 3 nomograms have been developed, including a preoperative, an early postoperative, and a 12-month postoperative version. The concordance indexes for all 3 exceeded 0.78, and the calibration was good. Clinical Implications: These nomograms may aid clinicians in discussing erectile function recovery with patients undergoing RP. Strengths & Limitations: Strengths of this study included a large population, validated instrument, nerve-sparing grading, and nomograms that are well calibrated with excellent discrimination ability. Limitations include current absence of external validation and an overall low comorbidity index. Conclusions: It is hoped that these nomograms will allow for a more accurate discussion between patients and clinicians regarding erectile function recovery after RP. Mulhall JP, Kattan MW, Bennett NE, et al. Development of Nomograms to Predict the Recovery of Erectile Function Following Radical Prostatectomy J Sex Med 2019;16:1796–1802.
AB - Introduction: Given the number of confounders in predicting erectile function recovery after radical prostatectomy (RP), a nomogram predicting the chance to be functional after RP would be useful to patients’ and clinicians’ discussions. Aim: To develop preoperative and postoperative nomograms to aid in the prediction of erectile function recovery after RP. Main Outcome Measures: International Index of Erectile Function (IIEF) erectile function domain score-based erectile function. Methods: A prospective quality-of-life database was used to develop a series of nomograms using multivariable ordinal logistic regression models. Standard preoperative and postoperative factors were included. Main Outcome Measures: The nomograms predicted the probability of recovering functional erections (erectile function domain scores ≥24) and severe erectile dysfunction (≤10) 2 years after RP. Results: 3 nomograms have been developed, including a preoperative, an early postoperative, and a 12-month postoperative version. The concordance indexes for all 3 exceeded 0.78, and the calibration was good. Clinical Implications: These nomograms may aid clinicians in discussing erectile function recovery with patients undergoing RP. Strengths & Limitations: Strengths of this study included a large population, validated instrument, nerve-sparing grading, and nomograms that are well calibrated with excellent discrimination ability. Limitations include current absence of external validation and an overall low comorbidity index. Conclusions: It is hoped that these nomograms will allow for a more accurate discussion between patients and clinicians regarding erectile function recovery after RP. Mulhall JP, Kattan MW, Bennett NE, et al. Development of Nomograms to Predict the Recovery of Erectile Function Following Radical Prostatectomy J Sex Med 2019;16:1796–1802.
KW - Erectile Dysfunction
KW - Nomograms
KW - Prostate Cancer
KW - Radical Prostatectomy
UR - http://www.scopus.com/inward/record.url?scp=85072020095&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85072020095&partnerID=8YFLogxK
U2 - 10.1016/j.jsxm.2019.08.003
DO - 10.1016/j.jsxm.2019.08.003
M3 - Article
C2 - 31521569
AN - SCOPUS:85072020095
VL - 16
SP - 1796
EP - 1802
JO - Journal of Sexual Medicine
JF - Journal of Sexual Medicine
SN - 1743-6095
IS - 11
ER -
