Reply by Authors

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5. Kajiwara M, Inoue K, Usui A et al: The micturition habits and prevalence of daytime urinary incon- tinence in Japanese primary school children. J Urol 2004; 171: 403. 6. Kajiwara M, Inoue K, Kato M et al: Nocturnal enuresis and overactive bladder in children: an epidemiological study. Int J Urol 2006; 13: 36. 7. Jensen KM, Nielsen KK, Kristensen ES et al: Uroflowmetry in neurologically normal children with voiding disorders. Scand J Urol Nephrol 1985; 19: 81. 8. Dogan HS, Akpinar B, Gurocak S et al: Non- invasive evaluation of voiding function in asymp- tomatic primary school children. Pediatr Nephrol 2008; 23: 1115. 9. Hamano S, Yamanishi T, Igarashi T et al: Evalu- ation of functional bladder capacity in Japanese children. Int J Urol 1999; 6: 226. 10. Kajbafzadeh AM, Yazdi CA, Rouhi O et al: Uro- flowmetry nomogram in Iranian children aged 7 to 14 years. BMC Urol 2005; 5: 3. 11. Okubo K, Yoshimura Kanematsu A, Nishiyama H et al: Average shapes of uroflow curves of adult men. Presented at annual meeting of Interna- tional Continence Society, San Francisco, Califor- nia, September 29 –October 3, 2009. 12. Yeung CK, Diao M and Sreedhar B: Cortical arousal in children with severe enuresis. N Engl J Med 2008; 358: 2414. 13. Hjalmas K, Arnold T, Bower W et al: Nocturnal enuresis: an international evidence based man- agement strategy. J Urol 2004; 171: 2545. EDITORIAL COMMENT These authors present a method of judging abnor- mal pediatric uroflowmetry objectively by computer. This is a valuable contribution to science because in the literature this has only been done for bladder outlet obstruction in adults. For pediatric lower uri- nary tract symptoms only expert opinion exists. An expert system is described as that which produces an objective judgment of flow curves. A drawback of the study is that after repeat reading the concept of the system remained difficult for me to understand. The fact that staccato and interrupted flows were joined into 1 group makes it impossible to discrimi- nate dysfunctional voiding from underactive blad- der. By definition the staccato flow pattern has peaks and troughs without attaining the zero line while interrupted flow passes zero. Finally, the fact that only average to reasonable interobserver agreement was found between pediatric urologists ( 0.21 to 0.61), indicates that further studies of pediatric uroflowmetry are needed with better de- fined criteria. Tom P. V. M. de Jong Department of Pediatric Urology University Children’s Hospital University Medical Center Utrecht Utrecht, The Netherlands REPLY BY AUTHORS The interobserver agreement rate indicates that we are not speaking the same language regarding pediatric lower urinary tract symptoms, and the comparison of the uroflowmetry data from different institutes may be futile without objective standard- ization. We expect the present methodology will en- able analysis of pediatric uroflowmetry on a multi- institutional basis. The discrimination between staccato and inter- rupted pattern may not be straightforward. It is easy to define typical staccato and interrupted pat- terns but the actual clinical curves do not follow such simplification. How should one classify a curve with multiple peaks, which reaches the zero line once and does not reach it for the rest of troughs? How should one differentiate terminal dribbing from interrupted voiding? We cannot objectively define these 2 patterns. Also, it is not scientific to assume that dysfunctional voiding and underactive bladder function can be differentiated by uroflowmetry curve alone. The concept of the present system is simple, al- though the actual calculation procedure may be per- ceived as difficult. We are generating software for universal use of this patterning system, which will provide a patterning result from UFM parameters (ie gender, voided volume, maximal flow rate and amplitude of maximal fluctuation). The software will be available from the corresponding author upon request. OBJECTIVE UROFLOWMETRY CURVE PATTERNING IN CHILDREN WITH WETTING 1679

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OBJECTIVE UROFLOWMETRY CURVE PATTERNING IN CHILDREN WITH WETTING 1679

5. Kajiwara M, Inoue K, Usui A et al: The micturitionhabits and prevalence of daytime urinary incon-tinence in Japanese primary school children.J Urol 2004; 171: 403.

6. Kajiwara M, Inoue K, Kato M et al: Nocturnalenuresis and overactive bladder in children: anepidemiological study. Int J Urol 2006; 13: 36.

7. Jensen KM, Nielsen KK, Kristensen ES et al:Uroflowmetry in neurologically normal childrenwith voiding disorders. Scand J Urol Nephrol

EDITORIAL COMMENT

REPLY BY AUTHORS

once and does not reach it for the re

8. Dogan HS, Akpinar B, Gurocak S et al: Non-invasive evaluation of voiding function in asymp-tomatic primary school children. Pediatr Nephrol2008; 23: 1115.

9. Hamano S, Yamanishi T, Igarashi T et al: Evalu-ation of functional bladder capacity in Japanesechildren. Int J Urol 1999; 6: 226.

10. Kajbafzadeh AM, Yazdi CA, Rouhi O et al: Uro-flowmetry nomogram in Iranian children aged 7 to

st of troughs? upon request.

11. Okubo K, Yoshimura Kanematsu A, Nishiyama Het al: Average shapes of uroflow curves of adultmen. Presented at annual meeting of Interna-tional Continence Society, San Francisco, Califor-nia, September 29 –October 3, 2009.

12. Yeung CK, Diao M and Sreedhar B: Corticalarousal in children with severe enuresis. N EnglJ Med 2008; 358: 2414.

13. Hjalmas K, Arnold T, Bower W et al: Nocturnalenuresis: an international evidence based man-

1985; 19: 81. 14 years. BMC Urol 2005; 5: 3. agement strategy. J Urol 2004; 171: 2545.

These authors present a method of judging abnor-mal pediatric uroflowmetry objectively by computer.This is a valuable contribution to science because inthe literature this has only been done for bladderoutlet obstruction in adults. For pediatric lower uri-nary tract symptoms only expert opinion exists. Anexpert system is described as that which producesan objective judgment of flow curves. A drawback ofthe study is that after repeat reading the concept ofthe system remained difficult for me to understand.The fact that staccato and interrupted flows werejoined into 1 group makes it impossible to discrimi-

der. By definition the staccato flow pattern haspeaks and troughs without attaining the zero linewhile interrupted flow passes zero. Finally, thefact that only average to reasonable interobserveragreement was found between pediatric urologists(� 0.21 to 0.61), indicates that further studies ofpediatric uroflowmetry are needed with better de-fined criteria.

Tom P. V. M. de Jong

Department of Pediatric UrologyUniversity Children’s Hospital

University Medical Center Utrecht

nate dysfunctional voiding from underactive blad- Utrecht, The Netherlands

The interobserver agreement rate indicates thatwe are not speaking the same language regardingpediatric lower urinary tract symptoms, and thecomparison of the uroflowmetry data from differentinstitutes may be futile without objective standard-ization. We expect the present methodology will en-able analysis of pediatric uroflowmetry on a multi-institutional basis.

The discrimination between staccato and inter-rupted pattern may not be straightforward. It iseasy to define typical staccato and interrupted pat-terns but the actual clinical curves do not followsuch simplification. How should one classify a curvewith multiple peaks, which reaches the zero line

How should one differentiate terminal dribbing frominterrupted voiding? We cannot objectively definethese 2 patterns. Also, it is not scientific to assumethat dysfunctional voiding and underactive bladderfunction can be differentiated by uroflowmetry curvealone.

The concept of the present system is simple, al-though the actual calculation procedure may be per-ceived as difficult. We are generating software foruniversal use of this patterning system, which willprovide a patterning result from UFM parameters(ie gender, voided volume, maximal flow rate andamplitude of maximal fluctuation). The softwarewill be available from the corresponding author