JPediatr(RioJ).2016;92(2):109---110
www.jped.com.br
EDITORIAL
Retrospective
studies
in
lower
urinary
tract
dysfunction
do
matter
夽
,
夽夽
Estudos
retrospectivos
sobre
DTUI
Israel
Franco
a,baNewYorkMedicalCollege,Valhalla,UnitedStates bMariaFareriChildren’sHospital,Valhalla,UnitedStates
The article ‘‘Clinical course of a cohort of children with non-neurogenicdaytimeurinaryincontinencesymptoms fol-lowed at a tertiary center’’1 highlights some important issues inthe management of lowerurinarytract dysfunc-tion (LUTD) in children. The first issue that is recognized is theneed for a consistentterminology in thisfield.The authorsusethetermurinaryretentiontodescribewhatis definedin the InternationalChildren’s ContinenceSociety (ICCS)standardizationdocumentasvoidingpostponement: Childrenwhohabituallypostponemicturitionusingholding maneuverssufferfromvoidingpostponement.Thiscreates ambiguityforthereaderandmakesitdifficulttoperforman accurateliteraturesearchtodofuturestudiesinthetopic. Weneedtohaveaconcertedeffortbyalltheauthorstouse standardizedterminologytohelptheprofessioncontinueto advancescientifically.
Ihaverespectfor theeditorsofthisjournalbeing will-ing to accepta retrospective study, which has become a ‘‘pariah’’inacademiccirclesandjournals.Therehasbeen aconcertedbiasinclinicalmedicinetodownplay retrospec-tivestudiesaspoorqualitymedicalresearchinlieuofother prospectivestudiesthatareofmarginalvalue.Ihaveseenan inordinatenumberofpapersandabstractsbeingpresented based on database reviews of billing or diagnostic data,
夽 Please cite this article as: Franco I. Retrospective studies
in lower urinary tract dysfunction do matter. J Pediatr (Rio J). 2016;92:109---10.
夽夽SeepaperbyLebletal.inpages129---35.
E-mail:isifranco@gmail.com
withno input of patient information. The pediatric urol-ogyconferencesarerifewiththesestudies,withconference coordinatorsenamoredbythefactthattheseare prospec-tivestudiesandareratedhigherthanretrospectivestudies. Theother formofstudythat hasbecomeprevalentisthe prospectivedatabasestudy,withtheauthorsrating subjec-tivefindings themselves. We are seeing numerous studies likethiscometoconferencesandpublicationbecausethey areprospective, so theysurely must be better. How can someonereviewinghisorherownoutcomes,whilealready knowingwhatthehypothesisis,reallyproduceanunbiased study?Forsomereason,editorsandthoseinchargeof con-ferenceshave given these studies greater relevance than the retrospective reviews. Good respective reviews,such asthisone,canofferatremendousamountofknowledge. Yes, there are limitations with retrospective studies, but aslongastheyarerecognizedandappropriately acknowl-edged,they shouldnotprevent thepresentation of novel data.Insomecases,retrospectivereviewscanreducebias. How?Ifthe patients weretreated withnoprior intentto publishthedata,thelikelihoodthatthepractitionerswould bepushedtoachieveahypothesisoutcomearelower.Ifthe personreviewingthedataisdifferentfromthecaretaker,it alsotendstoreducetheriskofbias.Weneedretrospective reviewstogiveuspilotstudies withnovelconcepts; with-outthis,wewouldhavetowaityearsfortheperfectstudy. Havingbeeninvolvedinclinicaltrialsfordrugsattempting toachieveapprovalintheUSandEurope,itcantakealong timeforthesestudiestocome tofruition.Itisevenmore devastatingifthewronghypothesisisestablished;then,the wholestudycouldbefornaught.Insomecases,whatcould
http://dx.doi.org/10.1016/j.jped.2016.01.002
110 FrancoI.
havebeen a novel conceptcan gounrecognized. Thereis aplacefor well-doneandthoroughretrospective reviews, suchasthisstudy.
The other important aspect of this paper is that the authorshave concludedwhat Ihave been advocating and othershaveshown:thatthereisalimitedrolefortheuseof urodynamicsintheevaluationofchildrenwithLUTD.They notedthat36/38patientshadurodynamicabnormalitiesand twodidnothaveanyabnormalities.Letusanalyzethis fur-ther and see if it really was necessary to perform these procedures.Astheauthorshaveshownthatagoodhistoryis criticalandveryvaluableinobtainingadiagnosis,thefact isthatoveractivityasevidencedbyurgency,urge inconti-nence,andfrequency wouldmorethanlikelybeevidence of detrusor instability on urodynamics. Even if the child hasurodynamicallyprovendetrusorinstability,isthe treat-mentgoingtobeanydifferent?Theanswerisanemphatic no. We would treat overactive symptoms the same way whetherdetrusorinstabilitywasorwasnotpresent.Whydo urodynamicsandputachildthroughanuncomfortable pro-cedureunnecessarily.Couldthedysfunctionalvoidinghave beendetectedwithouturodynamics?Ofcourseitcould.The use of uroflowmetry with electromyography(EMG) of the perineumand concomitant EMG of the abdomen provides goodproofof dysfunctionalvoiding,negatingthe need to dourodynamics.We can evendiagnosisinternal sphincter dyssynergiabyutilizinglagtimes,asdescribedbyCombsand Glassberg.2Bladderoveractivityhasbeenfoundtocorrelate withshortlagtimesandtowervoidingpatterns,makingit more likelyto make the diagnosis of diagnose overactive bladder(OAB)noninvasively.3Ourrecentpublication4 defin-ingaquantitativeapproachtouroflowmetryhelpsremove muchofthe subjectivityinreading curves.Weknow that there is great subjectivity in the process of determining whethercurvesarebellvs.plateauandbellvs.tower.Using aflowindexaswehavedevisedremoves thatsubjectivity andmakestheinterpretationofuroflowmetrymore objec-tive,renderingitamorepowerfultool.Theuseoftheflow indexcan leadto theability tofollow patients longitudi-nally,irrespectiveof ageorvolumevoided;thiscombined withEMGoftheperineumandabdomencreatesatoolthatis justaspowerfulasormoresothanurodynamics.Theauthors showusthattheyhavereachedahighconcordanceof85% bymakingthediagnosisofdetrusorinstabilitywithhistory andnon-invasivetests.Thisconfirmsourownbeliefsandthe workofBaeletal.5thatthereisalimitedplaceinthe man-agementofchildrenwithOABwithurodynamics.Thereare somerefractory patients inwhom urodynamics arecalled for;thesearethepatientswhomthepractitionerssuspect mayhaveaneurogenicbladder,orinsomecases,theywish toperformvideo-urodynamicsbecausethereisaneedfora voidingcystourethrogramandtheurodynamicsisdone con-comitantly.But,eventhisissomethingthatIwouldnotlook favorablyupon,sincetoperformurodynamicsarectal bal-looncatheterneedstobeinsertedandsedationcannotbe given,makingtheprocedureworsethanastand-alone void-ingcystourethrogram(VCUG) whichcan bedone usingan amnesticorpropofolanesthesia.
Ifthepractitionersseriouslysuspectthatthepatientmay haveaneurogenicbladder,thenitisprobablyadvisabletodo amagneticresonanceimaging(MRI)ofthespinebefore per-formingurodynamics.IftheMRIisnormal,thentheneedto
performurodynamicsisalmostnil,asevidencedbyaStone etal.,6whoshowedthatallpatientsthathadnormalMRIs didnothaveanythingbesidesdetrusorinstabilityon urody-namics.Ifoneisworriedaboutnon-neurogenicneurogenic bladder thatdiagnosis can bemadewitha VCUGshowing evidenceofseveretrabeculation,Christmastreeshape,and externalsphincterdyssynergiaorinternalsphincter dyssyn-ergia on the VCUG. Therefore, the need to use invasive urodynamicsshouldbeseverelyrestrictedinchildrenwith routinesymptomsofOAB.
Anotherfact thatwasinteresting in the article is that theauthorsmadenotethattheydidnotfindanassociation betweenobesityandvoidingsymptoms,ashasbeennoted intheliterature.Thismaybeexplainedbyarecentarticle byWangetal.7thatlookedatbehavioralproblemsinearly adolescenceinacohortofpatientsinHongKong.Theydid notfindalinkbetween obesityandemotional and behav-ioralproblems.Weknowthereisalinkbetweenemotional and behavioralproblems andurinaryincontinencein chil-drenandadults.Therefore,byextension,wecanpresume thatthelackofobesityandLUTDinthiscohortofpatients maybegeographic,ethnic,societal,and/orpossiblydueto culturalvariationsthatcouldprecludethedevelopmentof obesity in certain areas of the world. In this case, if the groupofchildreninthisstudywasdrawnfromapopulation of children withlessaccess tofood,then we couldsee a lowerincidenceofobesityinthisstudy,andpossiblynegate thefindings thathave beenobserved inthe UnitedStates andEurope,whereobesityisanepidemic.
Conflicts
of
interest
Prof.IsraelFrancoisaconsultantandclinical investigator forAstellas,Allergan,andLaborieMedicalTechnologies.
References
1.Lebl A, Fagundes SN, Koch VH. Clinical course of a cohort ofchildrenwithnon-neurogenic daytimeurinary incontinence symptoms followed at a tertiary center. J Pediatr (Rio J). 2016;92:129---35.
2.CombsAJ,GrafsteinN,HorowitzM,GlassbergKI.Primary blad-derneckdysfunctioninchildrenandadolescentsI:pelvicfloor electromyographylagtime----anewnoninvasivemethodtoscreen forandmonitortherapeuticresponse.JUrol.2005;173:207---10, discussion210---211.
3.CombsAJ,VanBataviaJP,HorowitzM,GlassbergKI.Shortpelvic floorelectromyographiclagtime:anovelnoninvasiveapproach todocumentdetrusoroveractivityinchildrenwithlowerurinary tractsymptoms.JUrol.2013;189:2282---6.
4.Franco I, Shei-Dei Yang S, Chang SJ, Nussenblatt B, Franco JA. A quantitative approach to the interpretation of uroflowmetry in children. Neurourol Urodyn. 2015 Jul 14, http://dx.doi.org/10.1002/nau.22813[Epubaheadofprint].
5.BaelA,LaxH,deJongTP,HoebekeP,NijmanRJ,SixtR,etal. TherelevanceofurodynamicstudiesforUrgesyndromeand dys-functionalvoiding:amulticentercontrolledtrialinchildren.J Urol.2008;180:1486---93,discussion1494---1495.
6.StoneJJ,RozzelleCJ,GreenfieldSP.Intractablevoiding dysfunc-tioninchildrenwithnormalspinalimaging:predictorsoffailed conservativemanagement.Urology.2010;75:161---5.
