EURURO Vol. 72 No. 6

E175 1030

Letter to the Editor
Re: Philipp Mandel, Felix Preisser, Markus Graefen, et al.
High [1_TD$DIFF]Chance of [2_TD$DIFF]Late [3_TD$DIFF]Recovery of [4_TD$DIFF]Urinary and [5_TD$DIFF]Erectile
[6_TD$DIF F]Function [7_TD$DIFF]Beyond 12 [8_TD$DIFF]Months [9_TD$DIFF]After [10_TD$DIFF]Radical [11_TD$DIFF]Prostatectomy.
Eur Urol 2017;71:848–50
Mandel et al described a remarkable study on functional
outcomes after radical prostatectomy (RP), with a special
emphasis on urinary incontinence. Although they reported
a novel outcome using a large single cohort, several points
need to be highlighted for a better understanding of the
study.
First, we need to consider that the reported prevalence of
urinary incontinence after RP was widely variable, ranging
from 2.5% to 87% . Major reasons for this discrepancy
were the absence of a uniform definition of urinary
incontinence and recovery of urinary incontinence, the
use of various diagnostic tools, and diverse follow-up
periods .
However, although the study involved a data set
consisting of their own single-institution cohort with a
set follow-up period, the analysis was performed as for
panel data. Kaplan-Meier estimators considering follow-up
loss would have better merit than merely analyzing a cross-
sectional fraction rate. In a data set that includes nationally
representative data or population-based claims data,
analysis of the fractional rate of recovery is sufficient
because of the lower probability of follow-up loss. If the
study did not consider patients lost to follow-up and
excluded them from the whole data set, this is problematic
in two ways. First, the article does not mention any patients
lost to follow-up in the study, including the section on
exclusion criteria. This is an important factor, since it
directly relates to the final conclusion of a positive outcome
for urinary incontinence after RP. Second, the reported
prevalence would be overestimated.
This study represents a novel finding for a single large
cohort and a precise definition of incontinence and
incontinence recovery. However, the limitation of the
cross-sectional recovery rate in the current analysis hinders
a more objective conclusion. Future studies including
conditional survival analysis for incontinence recovery
and considering variables including age, surgeon volume,
surgery types, pre-existing voiding dysfunction, and patient
comorbidities are warranted.
Conflicts of interest: The authors have nothing to disclose.
Acknowledgments: This study was supported by the Soonchunhyang
University Research Fund. The sponsor played a role in manuscript
preparation.
References
[1]
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[2]
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[3]
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[4]
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Jae Heon Kim a,b,*
Bora Leec
Benjamin I. Chunga
a Department of Urology, Stanford University Medical Center, Stanford, CA,
USA
bDepartment of Urology, Soonchunhyang University Hospital,
Soonchunhyang University Medical College, Seoul, Korea
cDepartment of Biostatistics, Clinical Trial Center, Soonchunhyang
University Bucheon Hospital, Bucheon, Korea
*Corresponding author. Department of Urology, Soonchunhyang
University Seoul Hospital, 59 Daesagwan-ro, Yongsan-gu,
Seoul 140-743, South Korea. Tel. +82 2 7099378; Fax: +82 2 7105190.
E-mail address: (J.H. Kim).
June 21, 2017
ava ilable at
journal homepage:
DOI of original article: .
0302-2838/# 2017 European Association of Urology. Published by Elsevier B.V. All rights reserved.