Development of The Viking Speech Scale to Classify the Speech of Children with Cerebral Palsy

Development

of

The

Viking

Speech

Scale

to

classify

the

speech

of

children

with

cerebral

palsy

Lindsay

Pennington

*

,

Daniel

Virella

,

Tone

Mjøen

,

Maria

da

Grac¸a

Andrada

,

Janice

Murray

,

Allan

Colver

,

Kate

Himmelmann

,

Gija

Rackauskaite

,

Andra

Greitane

,

Audrone

Prasauskiene

,

Guro

Andersen

,

Javier

de

la

Cruz

a_{InstituteofHealthandSociety,NewcastleUniversity,SirJamesSpenceInstitute,RoyalVictoriaInfirmary,}

NewcastleuponTyneNE14LP,UK

b

HospitaldeDonaEstefaˆnia,CentroHospitalardeLisboaCentral,RuaJacintaMarto,1169-045Lisboa,Portugal

c

VestfoldHospitalTrust,Postbox2168,N-3103Tønsberg,Norway

d

Federac¸a˜odasAssociac¸o˜es PortuguesasdeParalisiaCerebral,AvenidaRainhaDonaAme´lia,1600-676Lisboa,Portugal

e

FacultyofHealth,Psychology&SocialCare,ManchesterMetropolitanUniversity,HathersageRoad,ManchesterM130JA,UK

f

DepartmentofPediatrics,InstituteofClinicalSciences,QueenSilviaChildren’sHospital,SahlgrenskaAcademyattheUniversityof Gothenburg,Go¨teborg,Sweden

g_{DepartmentofPaediatrics,UniversityHospital,Aarhus,Denmark} h

RehabilitationCenter‘‘Mesesamlidzas’’,Riga1039,Latvia

i

Children’sRehabilitationHospitalaffiliatedtotheHospitalofLithuanianUniversityofHealthSciences,Kaunas,Lithuania

j

ClinicalResearchUnit,Imas12-Ciberesp,Hospital12Octubre,Madrid,Spain

ARTICLE INFO

Articlehistory: Received17April2013

Receivedinrevisedform22June2013 Accepted25June2013

Availableonline24July2013

Keywords: Cerebralpalsy Surveillance Speech Dysarthria Children Classification ABSTRACT

Surveillance registers monitor the prevalence of cerebral palsy and the severity of resultingimpairmentsacrosstimeandplace.Themotordisordersofcerebralpalsycan affect children’s speech production and limit their intelligibility. We describe the developmentofascaletoclassifychildren’sspeechperformanceforuseincerebralpalsy surveillanceregisters,anditsreliabilityacrossratersandacrosstime.Speechandlanguage therapists,otherhealthcareprofessionalsandparentsclassifiedthespeechof139children withcerebralpalsy(85boys,54girls;meanage6.03years,SD1.09)fromobservationand previousknowledgeofthechildren.Anothergroupofhealthprofessionalsratedchildren’s speechfrominformationintheirmedicalnotes.Withtheexceptionofparents,raters reclassifiedchildren’sspeechatleastfourweeksaftertheirinitialclassification.Raters wereaskedtoratehoweasythescalewastouseandhowwellthescaledescribedthe child’s speech production using Likertscales. Inter-rater reliability was moderate to substantial(k>.58forallcomparisons).Test–retestreliabilitywassubstantialtoalmost perfectforallgroups(k>.68).Over74%ofratersfoundthescaleeasyorveryeasytouse; 66%ofparentsandover70%ofhealthcareprofessionalsjudgedthescaletodescribe children’sspeechwellorverywell.WeconcludethattheVikingSpeechScaleisareliable tooltodescribethespeechperformanceofchildrenwithcerebralpalsy,whichcanbe appliedthroughdirectobservationofchildrenorthroughcasenotereview.

ß2013ElsevierLtd.Allrightsreserved.

*Correspondingauthor.Tel.:+441912821360;fax:+441912824725.

E-mailaddresses:lindsay.pennington@ncl.ac.uk(L.Pennington),danielvirella@oninetspeed.pt(D.Virella),tone.mjoen@siv.no(T.Mjøen),

mgcandrada@gmail.com(M.daGrac¸aAndrada),j.murray@mmu.ac.uk(J.Murray),allan.colver@ncl.ac.uk(A.Colver),kate.himmelmann@vgregion.se

(K.Himmelmann),gijarack@rm.dk(G.Rackauskaite),andra@edi.lv(A.Greitane),prasauskiene.a@takas.lt(A.Prasauskiene),guro.andersen@siv.no

(G.Andersen),jdlcruz@h12o.es(J.delaCruz).

ContentslistsavailableatSciVerseScienceDirect

Research

in

Developmental

Disabilities

0891-4222/$–seefrontmatterß2013ElsevierLtd.Allrightsreserved.

1. Introduction 1.1. Cerebralpalsy

Cerebralpalsyisdefinedasapermanentbutnotunchangingdisorderofmovementand/orpostureandofmotorfunction,

duetoanon-progressiveinterference/lesion/abnormalityofthedeveloping/immaturebrain(SurveillanceofCerebralPalsy

inEurope,2000).Itisthemostcommoncauseofmotordisorderinchildhoodaffectingaround2–3perthousandlivebirths (Cans,De-la-Cruz,&Mermet,2008). ‘‘Themotordisordersof cerebralpalsyareoftenaccompaniedbydisturbancesof

sensation,cognition,communication,perception,and/orbehaviour,and/orbyaseizuredisorder’’(Rosenbaumetal.,2007).

1.2. Surveillanceofcerebralpalsy

International surveillanceof cerebral palsy monitorstrends in theprevalence of cerebral palsyand measuresthe

functionalseverityoftheresultingimpairments,inordertoinformhealthandsocial carepolicyandpractice.Regional

registerscollectinformationonfactorsrelatingtobirth(e.g.gestationalage,birthweight),typeanddistributionofmotor

disorder,presenceandseverityofaccompanyingimpairmentssuchasvisionandhearing,andperformance.Forregistration

purposesconfirmationofadiagnosisofcerebralpalsyandassessmentofchildren’sfunctionusuallyoccursafteragefour,to

allowforresolutionof transientanomalies ordiagnosisofslowlyprogressivedisorders andtheappearanceofclinical

featuresnotmanifestinthefirstyearsoflife.ThenetworkofEuropeanregistries–SurveillanceofCerebralPalsyinEurope

(SCPE)–agreedthatfiveyearswastheoptimalageforconfirmationofdiagnosisandcaseregistration(Surveillanceof

CerebralPalsyinEurope,2000).

Surveillanceregistersvaryintheirmethodofdatacollection.Insomeregisters,clinicianscompletequestionnaires

on children’s diagnoses, impairment andfunction and return this information to the surveillance centre. Inother

registers, surveillance centre staff (who may not be clinicians) extract information from children’s health records

(EURO-PERISTAT, 2008). Extensive, clinical assessments are rarely practicable for surveillance purposes becauseof

thetimetakenforcompletion andvariation in personnelreportingdata. Easytousescales havebeen developedto

describe the gross motor performance (Palisanoet al.,1997)and manual performance (Beckung &Hagberg, 2002;

Eliasson et al., 2006) of children with cerebral palsy and are now used across surveillance registers rather than

detailedclinicalassessments suchastheGrossMotorFunctionMeasure(Russellet al.,1993)ortheABILHAND-Kids

(Arnould,Penta,Renders,&Thonnard, 2004).Theuseofcommon, consistentmeasuresby registershasenabled the

comparison ofprevalenceratesbyseverityofimpairmentacross timeandregions(Arnesonetal.,2009;Plattetal.,

2007;SCPE,2002).

1.3. Speech,communicationandcerebralpalsy

Twosystemstoclassifychildren’scommunicationhavebeendeveloped.Onedescribeschildren’sperformanceinsending

andreceivingmessages(Hideckeretal.,2011);theotherratesexpressiononly(Barty&Caynes,2009).Thesescalesclassify

children’ssuccessincommunicatinginformationusingtheirusualmodesofcommunication.Forchildrenwithcerebral

palsy, communication may be accomplishedvia multiple modes, suchas speech, vocalisation, and aided or unaided

augmentativeandalternativecommunicationsystems.Ascerebralpalsyalwaysinvolvesamotordisorderandchildrenmay

alsohaveotherdevelopmentaldifficulties,forsurveillancepurposesitisimportanttoknowtheextenttowhichchildren’s

communicationdifficultiesareassociatedwithmotorspeechdisorder.

Themotordisordersofcerebralpalsymayaffectthespeed,range,strength,coordinationandaccuracyofmovementsof

thevocaltract,leadingtothemotorspeechdisorderdysarthria(Duffy,2005).Controlofallspeechsystems–respiration,

phonation,resonance,articulationandprosody–maybeimpaired(Patel,2003;Yorkston,Beukelman,Strand,&Bell,1999).

Forexample,childrenwithcerebralpalsymayhaveshallow,irregularbreathingforspeech(forinstancespeakingonsmall

pocketsofresidualair);theirvoicemaysoundharshandhavelittlepitchvariation;airmayescapethroughtheirnoseduring

speechandtheymayhaveareducedrangeofvowelsandconsonantsthattheycanproduceclearly.Severityrangesfrom

mildwithslightimprecisionofspeechmovementstoprofoundwithinabilitytocoordinatethesubsystemstoproduceany

recognisablewords.Thespeech systemsmay bedifferentiallyaffected,forexamplerespirationmaybeinsufficientto

supportclearspeechbutarticulationofarangeofconsonantsmaybepossible.Impairmentsareusuallymoreseverefor

children withdyskineticcerebral palsythan thosewithspastic forms,but mostoftheperceptual characteristics(e.g.

harshnessofvoice,mono-pitch)areobservedinthespeechofchildrenacrossthedifferenttypesofcerebralpalsy(Love,

2000;Workinger&Kent,1991).

Speechproductioncanbemeasuredattheindividualspeechsubsystemlevel.Forexample,schemeshavebeendeveloped

torateimpairmentofphonationthroughperceptualvocalprofilescalesratingharshnessandaesthaenia(Hirano,1981).

However,a globalmeasureisnecessaryforepidemiologicalsurveillancepurposes.Theglobalmeasureshouldmeasure

speechperformance,thatis,howspeechisproducedindailylifetocommunicateinformation.Suchaschemeshouldclassify

1

theperceptualcharacteristicsofspeechassociatedwithunderlyingfunctionofspeechsubsystems(respiration,phonation, etc.)butmightalsoincludespeechintelligibility,asthepurposeofspeechistoconveyinformation(Dykstra,Hakel,&Adams, 2007;HUI,2003).

1.4. Reviewofspeechclassificationsystems

Weundertookareviewoftheliteraturetoinvestigateifglobalscalesofspeechfunctioninchildhooddysarthriahadbeen

developedandtestedintermsoftheirreliabilityandvalidity.InJune2010wesearchedforspeechclassificationtoolsvia

Medline,CINAHL,EMBASE,PsychInfo,WebofKnowledge,Scopus,FirstSearch,ERIC,LinguisticsandLanguageBehaviour

Abstracts and DARE, searching papers that were indexed under the terms speech production measurement/speech

articulationtestsor papers that includedparticipantswith cerebral palsyand were indexedunder theterms speech

disorders,articulationdisorders,communicationdisordersordysarthria.Wealsohand-searchedthefollowingjournalsfrom

theirinception orfrom1980until endMarch2010: AmericanJournal of Speech-LanguagePathology; Augmentative and

AlternativeCommunication;DevelopmentalMedicineandChildNeurology;FoliaPhoniatrica;InternationalJournalofLanguage

andCommunicationDisorders;InternationalJournalofRehabilitationResearch;JournalofCommunicationDisorders;Journalof

MedicalSpeech-LanguagePathology;JournalofSpeech,LanguageandHearingResearch;Speech,LanguageandHearinginSchools.

(Thecurrenttitlesaregivenforjournalsexperiencingnamechangessince1980.)

Wefoundtwoscales.TheSpeechProductionRatingScale(SPRS)(Pennington&McConachie,2001)classifieschildren’s

speech according tothree criteria: severityof motor speech disorder, phonemic structureof words produced, and

intelligibilitytofamiliarandunfamiliaradultsinandoutofcontext.Inter-raterreliabilitybetweentwoexperiencedspeech

and language therapists was calculated using percentage agreement (83%), therefore failing to correct forchance

agreement.Thescale’sreliabilityhasnotbeentestedwithothergroupsofraterswhomaycompletesurveillancemeasures

andwhomaybelessfamiliarwithlinguisticconceptssuchaswordstructure.Furthermore,itisunclearhowratersshould

prioritise the different dimensions captured within the scale when classifying children’s performance and how

impairments of speech subsystems other than articulation, such as respiration and phonation are accommodated.

Andersen,MjøenandVikclassifiedthespeechofchildrenontheNorwegiancerebralpalsyregisteraccordingtotheir

speechclarityusingafivepointscale(normalspeech,slightlyindistinct,obviouslyindistinct,severelyindistinct,noverbal

speech)(Andersen,Mjøen,&Vik,2010).This scalewouldseem torelatecloselytoarticulationandnootherspeech

characteristicsareincluded.Nodefinitionsforthefivelevels,ordifferentiationbetweenthelevels,wereprovidednorwas

informationonthescale’svalidityorreliability.Thusneitherofthescaleswasrobustintermsofvalidity,reproducibility

andreliability.

2. Aim

Theaimofthisstudywastodevelopascaletoindicatethepresenceofamotorspeechdisorderandspeechperformance

foruseincerebralpalsysurveillance.Theobjectivesweretotestthefacevalidityofthespeechscale,itscontentvalidity,its test–retestreliabilityanditsinter-raterreliability.Assurveillanceregistersoftencollectdatausinginformationfromcase

notes, we aimed to compare theagreement between ratings of children’s speech from direct observation and from

informationrecordedincasenotes.ThestudyispartofSCPE-NET(http://www.scpenetwork.eu),athree-yearprogrammeto

promotebestpracticeindescribingchildrenwithcerebralpalsyandtodocumentvariationsinaccesstohealthcareandin

healthoutcomes.ItfollowsdirectlyfromearlierSCPErecommendationsforconsistentdescriptionofchildrenwithcerebral

palsy(Cansetal.,2007).

3. Materialsandmethods

3.1. Developmentofthescale:contentvalidity

Aninternationalexpert groupcomprising twospeech and languagetherapists,oneoccupational therapistand one

neurodevelopmentalpaediatriciandevelopedtheinitialscale.Itwasdecidedthattheoriginalversionofthescalewouldbe

inEnglish.Wetookasourstartingpointthespeechofchildrenwithcerebralpalsywithwhomweworked(includinglive

observations,videotapedobservationsandaudiorecordings)anddescriptionsofspeechfromresearchpapersinvolving

childrenandadultswithcerebralpalsy.Wewantedthescaletoclassifytheperceptualcharacteristicsofchildren’sspeech

andtheseverityofmotorspeechdisorder.Wethereforedifferentiatedlevelsintheclassificationbytheextenttowhich

speechsubsystems–respiration,phonation,resonance,articulationandprosody–wereaffectedbyspeechmotordisorder.

As speech is used for the purpose of communication we also classifiedthe intelligibility of speech. We considered

intelligibilitytounfamiliarlistenersonly,toallowforcodingwithoutobservationofthechildoutsideclinicalenvironments

andtoreducecomplexity.Preliminaryversionsofthescalewerediscussedverballyandviaemailbythedevelopmentgroup.

Anydisagreementsledtochangesinwordingofthelevels.Thepenultimateiterationofthescalewasreviewedbythree

furthercontentexperts (specialistspeechand languagetherapistsworkingwithchildren withcerebral palsy)forface

validity.Thefeedbackfromtheseexpertsledtoachangeinorderoftheinformationinthedescriptors,withintelligibility

Thefinalisedscale–TheVikingSpeechScale–comprisedfourlevels:

I.Speechisnotaffectedbymotordisorder.

II.Speechisimprecisebutusuallyunderstandabletounfamiliarlisteners.Loudnessofspeechisadequateforonetoone

conversation.Voicemaybebreathyorharshsoundingbutdoesnotimpairintelligibility.Articulationisimprecise;most

consonantsareproduced,butdeteriorationisnoticeableinlongerutterances.Althoughdifficultiesarenoticeable,speech

isusuallyunderstandabletounfamiliarlistenersoutofcontext.

III.Speechisunclearandnotusuallyunderstandabletounfamiliarlistenersoutofcontext.Difficultiescontrollingbreathing

forspeech–canproduceonewordperutteranceand/orspeechissometimestooloudortooquiettobeunderstood.

Voicemaybeharshsounding;pitchmaychangesuddenly.Speechmaybemarkedlyhypernasal.Averysmallrangeof

consonantsareproduced.Theseverityofthedifficultiesmakesthespeechdifficulttounderstandoutofcontext.

IV.Nounderstandablespeech.

ExplanationsofthedifferencesbetweenlevelsIandIIandlevelsIIandIIIwereprovidedinthescale.Thefullscalecanbe

foundathttp://www.scpenetwork.eu/en/about-scpe/scpe-net-project/harmonisation/communication/.

The scale was translated into Danish, Latvian, Lithuanian, Norwegian, Portuguese (Portugal), Spanish (Spain) and

Swedish, following international guidelines that included two independent translators, discussions on phrasing and

terminologybytwofocus-groups(parentsandhealthprofessionals)andbacktranslation,toensureretentionoforiginal

concepts and meaning (Beaton, Bombardier, Guillemin,&Ferraz, 1976). Examplesof phoneme substitutionsgiven to

describetypicallydevelopingspeechwereadaptedtoeachlanguage.Backtranslationswerecheckedandapprovedbythe

firstauthor.Focusgroupsagreedthatthescalereflectedspeechimpairmentanditsimpactonintelligibilityineachlanguage,

andthatlevelswithinthescaleweredifferentiable.

3.2. Applicationofthescale–psychometrictesting

Totestthecontentvalidityandreliabilityofthescaleweaskedparents(orcaretakers),speechandlanguagetherapists

andotherhealthcareprofessionalstoapplythescaletoclassifythespeechofchildrenwithcerebralpalsyandratetheir

experienceofapplyingthescheme.

3.2.1. Participants:children

Thespeechofaconveniencesampleof139childrenagedfourtothirteenyears(85boys,54girls,meanage6.03years,SD

1.09years)withcerebralpalsywasratedforthestudy.ThechildrenwerepurposivelysampledfromsevenSCPEsurveillance

centres(NorthofEngland,Portugal(LisbonandOporto),Latvia,Lithuania,Norway,Spain(Madrid),WesternSweden),to

provideasampleateachcentrethatvariedinclinicaltypeofcerebralpalsy,grossmotorfunctionandcognitiveskills.

Denmarkdidnotparticipateinthesamplingofchildren.

Dataonchildren’smotor,sensoryandintellectualfunctionwerecollectedusingtheclassificationschemesusedbySCPE,

toshowchildren’swiderangingseverityofimpairments.Mostchildrenhadspastictypecerebralpalsy(n=104;76.1%;

unilateraln=35,bilateraln=69);28(19.9%)haddyskinetictypeand7(4.6%)hadataxictypecerebralpalsy.Followingusual

practiceinSCPEsurveillance,IQwasclassifiedbypaediatriciansfromclinicalobservationsandmedicalnotesusingathree

pointscale:41(29.54%)childrenwereclassifiedashavinganIQoflessthan50;25(18.0%)hadIQ50–69;56(40.3%)hadIQ

above70andtheIQof17(12.25%)wasunknown.GrossmotorfunctionwasclassifiedusingtheGrossMotorFunction

Classification System (GMFCS) (Palisano et al., 1997), upper limb function was classified using the Manual Ability

ClassificationSystem(MACS)(Eliassonetal.,2006)andtheBimanualFineMotorFunctionscale(BFMF)(Beckung&Hagberg,

2002)(Table1).Visionwasclassifiedusinga threepoint scale:67(48.2%)had novisualimpairment; 52(37.4%)had

impairmentbutnotsevere;16(11.5%)hadsevereimpairmentandthevisualfunctionoffour(2.9%)childrenwasunknown.

Hearingwasclassifiedinthesamemanner:122(87.8%)hadnoimpairment;six(4.3%)hadimpairmentbutnotsevere;three

(2.2%)hadsevereimpairmentandthehearingofeight(5.8%)childrenwasunknown.Usualmodesofcommunicationwere

recorded:96ofthechildren(69.1%)hadsomefunctionalspeech;56(40.3%)usedvocalisations;34(24.5%)usedgestures;22

Table1

Children’smotorfunctionasclassifiedusingtheGMFCS,MACSandBFMF.

Level GMFCS n=139(%) BFMF n=138(%) MACS n=138(%) I 32(23.0) 22(15.8) 18(12.9) II 16(11.5) 25(18.0) 33(23.7) III 27(19.4) 27(19.4) 25(18.0) IV 25(18.0) 20(14.4) 20(14.4) V 34(24.5) 22(15.8) 23(16.5) Unknown 5(3.6) 22(15.8) 19(13.7)

(15.8%)usedmanualsigns;31(22.3%)hadalighttechaugmentativeandalternativecommunication(AAC)bookand17

(12.2%)usedahightechAACdevice.

3.2.2. Participants:ratersofchildren’sspeech

Weaimedforeachchild’sspeechtoberatedbyaparent/caretakerthroughtheirknowledgeofthechild;byaspeech

andlanguagetherapistthroughdirect observationofthechild; by oneother healthcareprofessionalthroughdirect

observationandbyahealthcareprofessionalthroughaccesstocasenotes.Speechandlanguagetherapistsarerarein

Norway, andchildren receive services toaddress language and communication needs from special educators. The

speechofNorwegianchildreninthestudywasratedbyspecialeducatorsratherthanspeechandlanguagetherapists.

Foreasewehavereferredtothespecialeducatorsprovidinglanguageandcommunicationservicestochildreninthis

studyasspeechandlanguagetherapists.Intotal122childrenwereratedbytheircaretakers(98(80.3%)mothers;16

(13.1%)fathers;2(1.6%)otherrelative;6(4.9%)othercaretaker).Thespeechof129childrenwasratedbyspeechand

language therapists (special educators, Norway); 131 were rated by other healthcare professionals from direct

observation(22(16.8%)physiotherapists;58(44.3%)paediatricians,51(38.9%)otherhealthcareprofessionals)and134

wereratedusingcasenotes(1(.7%)physiotherapist;1(.7%)nurse;112(83.6%)paediatricians,20(14.9%)otherhealth

professionals).Ofthoseratingchildrenusingcasenotes,30(22.4%)recordedthattheyhadpreviousknowledgeofthe

child.

3.2.3. Procedure

Ethicspermissionwasobtainedfromeachoftheparticipatingcentres.Familieswererecruitedfromclinicalcaseloads

bylocalclinicians.Parentsgavewrittenconsenttoparticipateandfortheirchild’sskillstoberatedforthepurposeofthe

study.Eachraterwasprovidedwithacopyofthescaleintheirspokenlanguage.Notrainingonthescalewasprovided.Each

raterclassifiedchildren’sspeechskillsusingtheVikingSpeechScaleblindtootherraters’assessments.Atleastfourweeks

laterallhealthprofessionalswereaskedtorateeachchildagain,blindtotheiroriginalrating.Parentscompletedthescale

onlyonce.

Toinvestigate thecontentvalidity of thescale eachrater wasasked tocomplete Likertratingsof how wellthe

scaledescribestheperformanceofproducingspeech(1=verywell;5=verybadly).Thecomparisonofapplicationofthe

scalebydifferentgroupsofratersandthroughdirectobservationofthechildversusaccesstocasenotesenabledusto

assessthesuitabilityofthescaleforadoptionbysurveillanceregisterswhichcollectinformationindifferentways.To

enhance this assessmenteach respondent was asked ‘‘How easy did you find the applicationof this scale in this

particularchild?’’andtoanswer usinga 5pointscale(1=veryeasy; 2=easy;3=somedoubts;4=difficult;5=very

difficult). 3.2.4. Analysis

Test–retestreliabilityandinter-raterreliabilitybetweenratergroups(parent–speechandlanguagetherapist;parent–

otherhealthprofessionals;speechandlanguagetherapists–otherhealthprofessionals)wasassessedusingweightedKappa

(k),with95%confidenceintervals(95%CI).Ratingsofeaseofuseandcontentvalidityofthescalewerecomparedacross

ratersusingChisquare.AnalysiswascarriedoutusingStata,Release11(StataCorp,2009).

4. Results

4.1. AgreementofratingsonTheVikingSpeechScalebetweenratergroups

Inter-raterreliabilityoftheVikingScalewasobservedtobemoderate-substantialforallpairsofratergroups,withKappa coefficientsbeingintherangeof.58–.81,andlowerconfidencelimitsbeing.43orabove,forallpairsofratergroups(Landis& Koch,1977)(Table2showskapparesultswith95%CI.Percentageagreementandrawdatafortheindividuallevelsbypairsof

ratergroupsareprovidedintheSupplementarydatafile).

Table2

Inter-raterreliabilityusingweightedKappacoefficientswith95%confidenceintervals.

Ratergroups n k 95%CI

ParentsSLTs 126 .81 .66–.96

ParentsHCPdirectobservation 107 .58 .43–.73

ParentsHCPsusingnotes 117 .74 .60–.89

SLTsHCPdirectobservation 116 .58 .44–.73

SLTsHCPusingnotes 126 .78 .64–.92

HCPdirectobservationHPCusingnotes 123 .63 .49–.78 SLT,speechandlanguagetherapist;HCP,healthcareprofessional.

4.2. Test–retestreliabilityofTheVikingSpeechScale

Mostofthehealthcareprofessionalswhoratedthechildren’sspeechcompletedasecondrating,blindtotheiroriginal

rating,twotofourweekslater.Test–retestreliabilitywasalmostperfectforspeechandlanguagetherapists(n=97,k=89,

95%CI=.73–1.0),substantialforhealthcareprofessionalsbydirectobservation(n=72,k=68,95%CI=.50–.87)andalmost

perfect for healthcare professionals using case notes (n=61, k=92, 95%CI=.72–1.00) (Landis & Koch, 1977) (see

Supplementarydatafileforactualagreement).

4.3. EaseofuseofTheVikingSpeechScale

Mostratersfoundthescaleeasytoapply,withproportionallymorespeechandlanguagetherapistsfindingthescaleeasy

touse:74.6% ofparents;84.5%ofspeechandlanguagetherapists;77.6%ofhealthcareprofessionalsratingfromdirect

observationand74.1%ofprofessionalsratingusingcasenotesratedthescaleasveryeasyoreasytoapply(Fig.1).Theeffect

of ratergroupwasstatistically significant(

x

difficult/verydifficultcategories,suggestedthathealthprofessionalsratingspeechfromcasenotesfoundthescalemost

difficulttoapply(

x

small(9.3%).

Fig.1.EaseofapplicationoftheVikingSpeechScalebyratergroup.SLT,speechandlanguagetherapist;HCPdirect,healthcareprofessionalratingspeech fromdirectobservationofthechild;HCPnotes,healthcareprofessionalratingspeechfromcasenotes.

Fig.2.Raters’perceptionsofthefitofthedescriptionsintheVikingSpeechScalewiththechild’sspeech.SLT,speechandlanguagetherapist;HCPdirect, healthcareprofessionalratingspeechfromdirectobservationofthechild;HCPnotes,healthcareprofessionalratingspeechfromcasenotes.

4.4. ContentvalidityofTheVikingSpeechScale

Mostratersjudgedthescaletoratespeechperformancewell:66.4%ofparents,74.1%ofspeechandlanguagetherapists,

77.3%ofhealthcareprofessionalsratingthroughdirectobservationofthechildand70.9%ofhealthcareprofessionalsrating

childrenthroughaccesstocasenotesjudgedthescaletodescribethechild’sspeechwellorverywell(Fig.2).Again,theeffect ofratergroupwasstatisticallysignificant(

x

thecombinedcategories‘verywell/well’withallothercategoriescombined.(2)comparedthecombinedcategories‘very

badly/badly’withallotherratingcategoriescombined.Neithercomparisonshowedsignificantdifferencesbetweenrater

groupsinjudgmentsonwhetherthescaledescribedthechildren’sspeechwellorbadly.

5. Discussion

Thisstudyaimedtodevelopaneasytouse,validandreliablescaleofthespeechofchildrenwithcerebralpalsyforusein

thesurveillanceofcerebral palsy.Thescale incorporatesthepresenceofa motorspeech disorderandtheseverityof

limitations in speech performance in everyday life. The processof developing the scale wassimilar tothat of other

classificationscales(Eliassonetal.,2006)andtookasitsstartingpointthedescriptionofthespeechofchildrenwithcerebral

palsywithwhomweworkedwhohaddifferenttypesofmotordisordersandseveritiesofdysarthria.Multidisciplinary

experts (parents, speech and language therapists, occupational therapists, physiotherapists and paediatricians) were

involvedindevelopingthescale,andagreedonthedescriptionofspeechateachlevelandthedifferentiationbetweenlevels,

therebyensuringfacevalidity.Contentvaliditywasdemonstratedbythehighpercentageofratersfromallgroupsjudging

thescaletodescribewellorverywellthespeechofthechildrentheywererating.

Inter-raterreliabilityofthescalebetweengroupsfromdifferentbackgroundsandusingdifferentsourcesofinformation

(knowledgeofthechild,observationandcasenotes)wasmoderatetosubstantialforallraterpairs(Landis&Koch,1977).

Mostratersfoundthescaleeasytoapplyandratingswerestableovertime.Inbothinter-raterreliabilityandtest–retest

reliabilityassessments lowest reliabilitywas achievedfor healthcare professionals who ratedchildren’s speech from

observation.Thismaybeduetovariabilitywithinthehealthcareprofessionalsontheirknowledgeofthechildrentheywere

rating.Inordertoevaluateclassificationofchildren’sabilitiesinusualsurveillanceconditionsnostipulationsweremadeon

whetherthehealthcareprofessionalsshouldhavepriorknowledgeofthechildreninthisstudy.Lowerreliabilityforthis

groupmayalsoarisefromvariabilityintheirknowledgeofspeechdevelopment;speechandlanguagetherapistswhohave

greatestexpertiseinspeechdevelopment,foundthescaleeasiesttouse.Furtherresearchisneededtotesttheeffectof

familiaritywiththechildbeingcoded,familiaritywiththescale,andprofessionalgroup.

Togethertheseresultssuggestthatthescaleissuitableforadoptionbycerebralpalsysurveillancecentres,butthatitis

bestappliedbyhealthcareprofessionalsusingchildren’snotesandbyparentsorspeechandlanguagetherapistsfrom

observation.

TheVikingSpeechScalewasdevelopedtoclassifythepresenceofdysarthriaandlimitationsinspeechperformance.The

scalemaycomplementotherscales(Barty&Caynes,2009;Hideckeretal.,2011)ofcommunication,showingtheextentto

whichmotorspeechdisordersimpactoncommunicationperformance.

Likeotherschemesdesignedtoclassifychildren’sperformance,suchastheGMFCS(Palisanoetal.,1997),itrelieson

informationfromthedomainsofbothbodyfunctionandactivitywithintheInternationalClassificationofFunctioning,

DisabilityandHealth(ICF)(WHO,2001).Thescaledescribesthechildren’sspeechperformanceattheleveloftheindividual

speechfunctionsaffectedby dysarthria:breath supportforspeech, phonation,articulationandrhythm/prosody(Kim,

Martin,Hasegawa-Johnson,&Perlman,2010;Love,2000;Patel,2002a,2002b;Solomon&Charron,1998).Asthepurposeof

speechistoconveyinformation,levelswithinthescalearealsodifferentiatedaccordingtotheextenttowhichthespeech

signalcanbeunderstoodbyunfamiliarpeople–itsintelligibility.Intelligibilityofspeechiscodedasanactivity(‘Producing

Communication–Speaking’)intheICF(Dykstraetal.,2007).Childrenwhosespeechisdelayedindevelopment,butwhodo

nothavedysarthriawouldbeclassifiedas‘LevelI–speechnotaffectedbymotordisorder’,eventhoughtheirintelligibility

maybecompromised.Theinclusionofintelligibilitydescriptionsmaymakethescaleeasiertoapplybyindividualswith

littletheoreticalknowledgeofspeechdisorders.However,fromthecurrentstudyitisnotclearwhetherratersareusing

speech function or speech intelligibility descriptions to assign a level; such understanding would require cognitive

interviewingofratersapplyingthescale(Willis,1994).

TheVikingSpeechScalewasdesignedforandtestedwithchildrenagedfouryearsandabove.Thiswastoensurethatall

SCPEsurveillancecentres,whichhaveaminimumreportingageoffouryears,couldadoptthescaleifitwereshowntobe

validandreliable.Thescalecontainsonlyonesetoflevels;noagebandshavebeencreated.However,itisacknowledgedthat

atfouryearschildren’sphonologicalsystem,andpotentiallytheirintelligibility,willstillbedeveloping(Dodd,Holm,Hua,& Crosbie,2003)andintheintroductiontothescaleexamplesofdevelopmentalspeechsubstitutionsaregiven.Thescalemay

beeasiertoapplywitholderchildren,whosespeechhasmatured.However,furtherresearchisnecessarytoexamineifage

affectsreliabilityandeaseofapplication,andiflevelsontheVikingarestableovertime.

Unlikeotherclassificationsystems(Beckung&Hagberg,2002;Eliassonetal.,2006;Hideckeretal.,2011;Palisanoetal.,

1997),theVikingSpeechScalecontainsfourlevels.Thescale’slevelsweredeterminedbytheneedtocreatemeaningful

categoriesforepidemiologicalsurveillance.Thescaleisnotintendedtobeaclinicalassessment,butmaybehelpfulwhen

criterionvalidityofthescaleandresearchiscurrentlyunderwaytoassesstheassociationbetweentheVikingSpeechScale

andobjectivemeasuresofchildren’sspeechintelligibility(Pennington&Hustad,inpreparation).

Alimitationofthestudyisthelownumbersofchildreninthesamplefromsomeoftheparticipatingcountries.Each

centreaimedtorecruit30childrentothestudy,butforsomecentresthiswasnotpossibleforreasonsrelatingeithertothe

sizeoftheareacoveredortofinancialconstraints.Althoughthescalehasacceptableoverallreliability,itispossiblethat

reliabilityofthescalediffersbetweencountriesandlanguages,inspiteofculturaladaptationprocessesundertakenduring

translation.Furtherresearchwouldbenecessarytotestsimilarityinreliabilitybetweencountriesandlanguagesasthe

sample inthecurrentstudyistoosmalltoinvestigatethis issue.On theotherhand,itsmultinational designhasthe

advantagesofhighlightingthevalidityofthescaleasatooltobeusedforinternationalsurveillanceofcerebralpalsyand

providingvalidatedversionsofthescaleineightdifferentlanguages.

6. Conclusion

Fromitsapplicationwithasampleofchildrenwithcerebralpalsywhohadawiderangingmotor,cognitiveandsensory

skillsbyhealthcareprofessionalsfromobservationandusingnotesandbyparentsfromrecollectionofchildren’sspeech,we

haveshownthatthescalehasfaceandcontentvalidity,iseasytouseandreliable.Weconcludethatthescalecanbeapplied

by cerebral palsy surveillance registers that collect information from clinicians’ observations and those that collect

informationfromchildren’smedicalnotestodescribethespeechperformanceofchildrenwithcerebralpalsyagedfour

yearsandabove.

Acknowledgement

ThisstudywasfundedbytheEuropeanUnionHealthProgramme–GrantEAHC20081307–‘Surveillanceofcerebral

palsyinEurope:bestpracticeinmonitoring,understandingofinequalityanddisseminationofknowledge’.

AppendixA

ThefollowingSCPEcentrescollecteddataforthisstudy:Denmark(ledbyGijaRackauskaite),Latvia(ledbyAndraGreitane),

Lithuania(ledbyAudronePrasauskiene),Norway(ledbyGuroAndersen),Portugal(LisbonandOporto,ledbyDanielVirella),

Spain(Madrid,ledbyJavierdelaCruz),Sweden(WesternSweden,ledbyKateHimmelmann),UK(NorthofEngland,ledbyKaren

Horridge).

AppendixB. Supplementarydata

Supplementary data associated with this article can be found, in the online version, at http://dx.doi.org/10.1016/

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