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Preprint:Pleasenotethatthisarticlehasnotcompletedpeerreview.
MeasurementpropertiesoftheMusculoskeletalHealthQuestionnaire(MSK-HQ):abetweencountrycomparisonCURRENTSTATUS:UNDERREVIEW
DavidHøyrupChristiansen
[email protected]:https://orcid.org/0000-0001-7458-3921
GarethMcCrayInstititeforPrimaryCareandHealthSciences,KeeleUniversity
TrineNøhrWindingDeparmentofOccupationalMedicine,DanishRamazziniCentre,UniversityClinic,Herning
JohanHviidAndersenDeparmentofOccupationalMedicine,DanishRamazziniCentre,UniversityClinic,Herning
KentJacobNielsenDeparmentofOccupationalMedicine,DanishRamazziniCentre,UniversityClinic,Herning
SvenKarstensDeparmentofComputerScience;TherapeuticSciences,TrierUniversity
JonathanCHillInstituteforPrimaryCareandHealthSciences,KeeleUniversity
DOI:10.21203/rs.2.19546/v2
SUBJECTAREASHealthEconomics&OutcomesResearch
KEYWORDSpatientreportedoutcomes,usability,psychometrics,responsiveness,interpretability
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AbstractBackground:TheMusculoskeletalHealthQuestionnaire(MSK-HQ)hasbeendevelopedtomeasure
musculoskeletalhealthstatusacrossmusculoskeletalconditionsandsettings.However,theMSK-HQ
needstobefurtherevaluatedacrosssettingsanddifferentlanguages.
Objective:Theobjectiveofthestudywastoevaluateandcomparemeasurementpropertiesofthe
MSK-HQacrossDanish(DK)andEnglish(UK)cohortsofpatientsfromprimarycarephysiotherapy
serviceswithmusculoskeletalpain.
Methods:MSK-HQwastranslatedintoDanishaccordingtointernationalguidelines.Measurement
invariancewasassessedbydifferentialitemfunctioning(DIF)analyses.Test-retestreliability,
measurementerror,responsivenessandminimalclinicallyimportantchange(MCIC)wereevaluated
andcomparedbetweenDK(n=153)andUK(n=166)cohorts.
Results:TheDanishversiondemonstratedacceptablefaceandconstructvalidity.Outofthe14MSK-
HQitems,threeitemsshowedDIFforlanguage(pain/stiffnessatnight,understandingconditionand
confidenceinmanagingsymptoms)andthreeitemsshowedDIFforpainlocation(walking,
washing/dressingandphysicalactivitylevels).IntraclassCorrelationCoefficientsfortest-retestwere
0.86(95%CI0.81to0.91)forDKcohortand0.77(95%CI0.49to0.90)fortheUKcohort.The
systematicmeasurementerrorwas1.6and3.9pointsfortheDKandUKcohortsrespectively,with
randommeasurementerrorbeing8.6and9.9points.Receiveroperatingcharacteristic(ROC)curves
ofthechangescoresagainstpatients’ownjudgmentat3monthsexceeded0.70inbothcohorts.
AbsoluteandrelativeMCICestimateswere8-10pointsand26%fortheDKcohortand6-8pointsand
29%fortheUKcohort.
Conclusions:ThemeasurementpropertiesofMSK-HQwereacceptableacrosscountries,butseem
moresuitedforgroupthanindividuallevelevaluation.Researchersandcliniciansshouldbeaware
thatsomediscrepancyexitsandshouldtaketheobservedmeasurementerrorintoaccountwhen
evaluatingchangeinscoresovertime.
BackgroundPaininmusclesandjointsisoneoftheWesternWorld’schiefpublichealthconcernsandaleading
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causeofreducedfunctionalandworkingcapacity[1].Inordertodevelopeffectivetreatments,andto
evaluatetheireffects,reliableandvalidmeasurementtoolsareessential.Thehealth-related
consequencesofmusculoskeletaldisorders,suchasbackandkneepain,canrarelybeidentifiedor
measuredusingdiagnosticimagingorotherobjectivemeasurementmethods[2-5].Therefore,patient
reportedoutcomesmeasures(PROMs)areincreasinglyusedtosupporttheassessment,treatment
andmonitoringofpersonswithmusculoskeletaldisorders[6].PROMsrevealaperson’sperceived
symptoms,functionalabilityandqualityoflife,andaretypicallyadministeredviaquestionnaire.A
widerangeofquestionnairesformusculoskeletaldisordershavebeendeveloped.However,these
questionnairesaretypicallylimitedtospecificpartsofthebody,e.g.painintheshoulderandarm[7],
neckandback[8,9],hipandknee[10].Although,region-specificquestionnairesinspecificpatient
populationandclinicaltrialsservesitspurposewell,theycanoftenbedifficulttoadministratefor
healthcareprofessionals(e.g.generalpractitionersandphysiotherapists)inprimarycare,whosee
patientswithdiversemusculoskeletaldisorders,oftenpresentingwithconcurrentpainfromseveral
locations[11].Although,moregeneralmusculoskeletalquestionnairesexist[12,13],theseare
relativelycomprehensiveinlengthandthereforelesssuitedtoevaluatechangesovertime,because
oftheburdenofadministrationandpatientcompletionatmultipletimepoints.Inaddition,someonly
coverasmallnumberofhealth-relateddomains(e.g.painandfunction)[13],andtherebymaynotbe
sensitivetothemultidimensionalityoftreatmenttargetsinherentinmanagingmusculoskeletal
disorders.
Asaconsequence,VersusArthritis(https://www.versusarthritis.org)fundedcollaborationbetweenthe
universitiesofOxfordandKeeletodeveloptheMusculoskeletalHealthQuestionnaire(MSK-HQ)in
2012[14].TheMSK-HQaimstocapturepatientandclinicianprioritisedkeyoutcomesacrossarange
ofmusculoskeletalconditions.Theinstrumentconsistsof14itemsandcoversanumberofhealth-
relateddomains,includingsymptoms,physicalfunctioning,dailyactivitiesandwork,physicalwell-
being,confidencetomanagesymptoms,conditionunderstandingandsocialactivities.Eachitemon
theMSK-HQisansweredona5-pointverbalratingscale(responsescodedfrom‘notatall’=4to
‘extremely’=0,exceptforitems12‘understandingcondition’and13‘confidenceinmanaging
4
symptoms’,whichhavetheresponseoptionsinthereverseorder).Scoresaresummed,rangingfrom
0to56,where56isthebestpossiblestateofmusculoskeletalhealth.Therelativelybriefformat
makestheMSK-HQmoresuitabletomonitorandcomparemusculoskeletalhealthstatusacross
variousconditionsandthroughouttheclinicalpathway.TheoriginalversionoftheMSK-HQhas
demonstratedhighcompletionrates,goodtest-retestreliabilityandstrongconvergentvaliditywith
referencestandardsinfourdifferentMSKcohorts[14].However,aquestionnaire’susabilityand
measurementpropertiescannotnecessarilybetransferredtoothercountries,languagesand
healthcaresystems[15-17].Therefore,carefultranslation,cross-culturaladaptation,testingand
validationarenecessaryinordertotakeaccountanyculturalandcomprehensibility-related
differencesbetweenthecountries.Although,cross-culturaladaptationandwithincountryevaluation
oftenareperformedwithPROMs,assessmentofmeasurementinvariancewithrespecttolanguage
andpatientscharacteristics,aswellasdirectcomparisonofmeasurementpropertiesacrosscountries
arelessfrequent.Theobjectivesofthepresentstudywereto1)translateandcross-culturaladapt
theMSK-HQforuseinaDanish-speakingpopulation,and2)evaluateandcomparemeasurement
propertiesoftheMSK-HQacrossDanish(DK)andEnglish(UK)cohortsofpatientsconsultingprimary
carephysiotherapyserviceswithmusculoskeletalpain.
MethodsTranslationandcross-culturaladaptation
WetranslatedtheMSK-HQintoDanishinaccordancewithinternationalstandards[18].Thiswas
doneinclosecollaborationwiththelicenseholderoftheMSK-HQquestionnaire,OxfordUniversity
InnovationLtd(http://innovation.ox.ac.uk)andarepresentativeoftheresearchgroup,whodeveloped
thequestionnaire(JCH).AprofessionalEnglishlanguagetranslatorspecialisinginmedicaltranslation
andabilingualphysiotherapist,bothDanishnativespeakers,translatedthequestionnairefrom
EnglishintoDanish.Subsequently,theirtranslationswerecomparedataconsensusmeetinginthe
projectgroupwithparticipationofbothtranslators.AprofessionalnativeEnglish-speakingtranslator
back-translatedthequestionnairefromDanishintoEnglish,withoutanypriorknowledgeofthe
originalversion.Theback-translationwascomparedtotheoriginalversion.Afterwards,the
5
translationreportwasreviewedbyJCHandapproved.Finally,weperformedcognitivedebriefing
interviewswith13patientswithmusculoskeletaldisordersrecruitedinonephysiotherapyclinicinthe
CentralDenmarkRegion.Theresultsofthecognitivedebriefingwerepresentedandreviewedinthe
projectgroupandthefinalversionofthequestionnairewascompleted.
Designandstudypopulations
Thestudywasaprospectivecomparativestudyencompassingtwoconsecutivelyrecruitedcohortsof
patientswithmusculoskeletaldisordersinprimaryphysiotherapypracticeinDKandUK.
DKcohort
Participants
Consecutiveadult(≥18years)consultersreferredtophysiotherapywithamusculoskeletaldisorder
wereinvitedtoparticipateinsixphysiotherapy(PT)clinicsintheCentralDenmarkRegion.
ParticipantshadtobeabletounderstandandspeakDanishwellenoughtocompletequestionnaires,
withnofurtherinclusioncriteriaapplied.IntheperiodJanuary-July2017atotalof180patients
agreedtoparticipate,ofwhom27wereexcludeddueto‘noshow’/cancelations(n=9),withdrawal
(n=5),otherdiagnosisthanmusculoskeletal(n=2),otherreasons(n=4)ordidnotcompletebaseline
questionnaire(n=7),leaving153patientsforanalysis.
Datacollection
Atfirstcontact,thepatientwasinformedabouttheproject.Ifthepatientagreedtoparticipate,ane-
mailwithalinktoanelectronicquestionnairewassenttothepatient(baseline).Thequestionnaire
includedtheDanishversionsoftheMSK-HQ,thegenericEQ-5D-5L[19-21]andvalidatedreference
standardmeasuresdependingonthepainregionfromwhichthepatient’smainproblemoriginated;
ShortenedDisabilitiesoftheArm,ShoulderandHand(Q-DASH)[22,23],NeckandBackdisability
Indexes(ODIandNDI)[24-26],Pain,stiffnessandfunctionmodulesofKneeinjuryandHipDisability
OsteoarthritisOutcomeScores(KOOSandHOOS)[27-29].AnappointmentwasmadeforafirstPT
consultation(test-retest)5-7dayslater.Immediatelybeforethisappointment,thepatientoncemore
completedthequestionnaire.Follow-upquestionnairesweresentaftersixand12weeksbye-mail.In
addition,inretestandfollow-upquestionnaires,patientswereaskedtoratetheoverallchangein
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theirconditionona7-pointscale(muchbetter,better,slightlybetter,unchanged,slightlyworse,
worse,muchworse).Atotalof134patients(88%)completedthetest-retestquestionnaire(median
timeinterval6days[Interquartilerange3-8days]).Follow-upquestionnaireswerecompletedby118
patients(77%)atsixweeksand128patients(84%)at12weeks.ForcomparisonwiththeUKcohort
onlytheresultsofthe12-weekfollow-upareincludedinthepresentstudy.
UKcohort
Participants
TheUKcohortwasdrawnfromtheprimarycarephysiotherapysampleusedastheoriginalvalidation
cohortfortheMSK-HQ.Thedetailsofmaterialsandmethodshavepreviouslybeendescribed
elsewhere[14].Briefly,thecohortincluded210consecutiveconsultersincommunitymusculoskeletal
physiotherapyclinicsinfiveUKWest-Midlandstowns.Ofthose166(78%)withtest-retestdatawere
availableforthepresentstudy.
Datacollection
ParticipantscompletedtheEnglishpaperversionoftheMSK-HQandtheEQ-5D-5Lindexbeforethe
startoftreatmentatthefirstclinicvisit(baseline)andagainatthesecondvisit,typically2weeks
later(test–retest).Follow-upquestionnaireswerecompletedat12weeksby133(80%)patients.A
transitionquestiononoverallchangeintheconditionona5-pointscale(muchbetter,slightlybetter,
unchanged,slightlyworse,muchworse)wascompletedbypatientsattest-retestand12-weekfollow-
up.
Statisticalanalysis
Descriptivestatistics
Descriptivestatisticswerecalculatedforallvariablesandcomparedbetweenthetwocohorts.Sum
scoreswerecalculatedatalltimepointsandrawscoreswerecalculatedifnomorethan
3itemsweremissingintherespectivescore;otherwise,thescorewasleftmissing.Possiblefloorand
ceilingeffectswereexaminedandsucheffectswereconsideredtobepresentifmorethan15%ofthe
respondentsachievedthehighestorthelowestsumscore,respectively.
Constructvalidity
7
AsnoreferencestandardmeasureswerecollectedfortheUKprimarycarecohort[14],weonly
assessedconstructconvergentvalidityfortheDanishversionoftheMSK-HQ.Thiswasdoneby
correlationanalysesbetweentheMSK-HQscoresandtherelevantreferencestandardmeasures
scoresatbaseline(Q-DASH,ODI,NDIandWOMACscorescalculatedfromKOOSandHOOS).Likewise
longitudinalconvergentvaliditywasassessedbycorrelationanalysesbetweenMSK-HQandreference
standardmeasureschangescoresatthreemonths.Basedonfindingsfromtheoriginalvalidation
studyoftheMSK-HQ[14]andpreviousliteratureofhealthoutcomeresearch[30-32],weexpected
correlationsbetweenMSK-HQandrelevantreferencestandardmeasurestobeatmoderatetostrong
(r=≥0.5).
Cross-culturalvalidityandmeasurementinvariance
Measurementinvarianceaccordingtolanguage,categoriesofage,painsite,durationofpain,and
workstatus,wasassessedbyDifferentialitemfunctioning(DIF)analysisofbaselineratingsofthetwo
cohorts.DIFistheassessmentoftheextenttowhichitemsfunctiondifferentlybetweenvarious
groups,whenthescoresamongthosegroupsarecorrectedfor.UniformdichotomousDIFontheraw
scoreswasassessedinthispaperviatheMantel-Haenszel(MH)statisticcalculatedintheR3.4.1[33]
packagedifR[34].Itempurificationwasusedandadjustmentformultiplecomparisonswasmadevia
Holm’smethod.TheassessmentoftheeffectsizefortheDIFwasmadeontheETSDeltascaleforthe
dichotomouscategories(i.e.,country,duration,workstatus)[35].NotethatMSK-HQitemswere
dichotomisedsuchthatthetwolowerimpactcategories(‘notatall’and‘slightly/rarely’)opposedthe
threehigherimpactcategories.Furthermore,fortheassessmentofpainlocation,‘neck’was
collapsedwith‘back’asthereweretoofewinstancesofneckpaintocalculatetheMHstatistic
robustly.
Measurementerrorandreliability
Astest-retestwasadministereddifferentlyinthetwocohortswithrespecttotimeintervaland
initiationoftreatment,werestrictedtheanalysistopatientswhoreportedtheirconditiontobe
‘stable’betweenadministrations.SystematicmeasurementerrorbetweenMSK-HQscoresatbaseline
andretestwasanalysedbyBland-Altmanplotandpairedt-testfortheDKandUKcohorts.Further
8
randomerrorswereestimatedbystandarderrorofmeasurement(SEM)andminimaldetectable
change(MDC=1.96×√2×SEM)wascalculated.Cronbach’salphawascalculatedtoassessinternal
consistency.Theintraclasscorrelationcoefficient(ICC2.1)wasusedtoassesstest-retestreliability,
andforsingleitemsCohen’sKappawithquadraticweightswasused.Confidenceintervals(95%CI)
forKappavalueswereobtainedusingnon-parametricbootstrapmethods(1000replications).
Sensitivitytochange,responsivenessandinterpretability
ToevaluatesensitivitytochangeMSK-HQchangescoresfrombaselinetothreemonthsandeffect-
sizestatistics(i.e.,meanchange/standarddeviationatbaseline)werecalculatedandcompared
betweenthetwocohorts.ForresponsivenesstheMSK-HQ'sabilitytodiscriminatebetween
unchangedpatientswascalculatedandcomparedbetweencohortsbyreceiver-operating-
characteristic(ROC)curveanalyseswithlargeimprovement(muchbetter,betterversusalittle
better,unchanged,littleworse)andsmallimprovement(muchbetter,better,littlebetterversus
unchanged),usingthetransitionquestionasexternalanchor.Responsivenesstoworseningwasnot
analysed,asonlyfewpatientsratedtheirconditiontobe‘worse’or‘muchworse’.Minimalclinically
importantchange(MCIC)valueswereestimatedbythePythagoras'Theorem(a^2+b^2=c^2)to
choosethechangescoreclosesttotheupperleft-handcorner,whichbestdiscriminatedbetween
improvedandunchangedpatients[36].AsMCICvaluescanbeaffectedbybaselinescores,analysis
wasrepeatedwithrelativechangescores(i.e.,changescoresexpressedaspercentagesofthe
baselinescores)[37].Finally,asakeyvisonforthedevelopmentoftheMSK-HQwastoproducea
singlemusculoskeletalhealthmeasuresuperiortogenerichealthtools,wecomparedeffectsize
estimatesandareasundertheROCcurvefortheMSK-HQandtheEQ-5Dchangescores[38].The
statisticalpackageSTATAversion15wasused.
ResultsTranslationandcross-culturaladaptation
Inthetranslationprocessafewitemshadtobeslightlyrephrasedandtheresponsecategory
‘severely’waschangedto‘alot’tofittheDanishlanguage.Afewotherissueswereraisedduring
translation.Thetwodifferentconstructs;painandstiffnessusedinitem1anditem2ledtosome
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discussionintheprojectgroup,aswellasthedifferentconstructsinitem12‘understanding
condition’anditem13‘confidenceinmanaging’.However,cognitivedebriefinginterviewswithpilot
patients(fivemalesandeightfemales,32–59yearsofage)withvariousmusculoskeletaldisorders
revealednodifficultieswithrespecttotheabove-mentionedconcerns.Ingeneral,patientsfoundthe
DanishversionoftheMSK-HQeasytocomplete(2-6min)anditemswerewellunderstood,thusno
furtherchangeswereneeded.Patientsdidnotseemtodistinguishbetweenpainandstiffness,and
mostpatientsfoundtheitemsregardingunderstandingtheircondition(item12)andconfidencein
managing(item13)tobeimportant.TheDanishversionoftheMSK-HQisavailableonlicence
request:https://process.innovation.ox.ac.uk/clinical.
Descriptivestatistics
Thepatientcharacteristicsofbothcohortsarepresentedintable1.Thetwocohortswerefairly
similarwithrespecttodistributionofpainsites.ThepatientsintheDKcohortwereslightlyyounger,
includedmorewomen,andhadahigherpercentageofpatientswhowereworking.Nofloororceiling
effectswereobservedatanytimepoint.IntheDanishcohortmissingdatawasreplacedbymean
itemscoresfortwopatientswholefttwoitemsunansweredandtwopatientswholeftthreeitems
unansweredatbaseline,andtwopatientswholeftoneitematretestandfollow-up.FortheUKcohort
meanitemscorewascalculatedfortwopatientsleavingoneitemunanswered.
Constructvalidity
Thecorrelationcoefficients(SpearmanRho)betweentheDanishMSK-HQandrelevantreference
standardmeasureswere0.63(CI,0.38to0.79)fortheQ-DASH,0.71(CI,0.53to0.88)fortheODI,
0.60(CI,0.25to0.81)fortheNDI,andfortheWOMAC0.84(CI,0.73to0.91).Correspondingvalues
forchangescoreswere0.65(CI,0.38to0.82)fortheQ-DASH,0.74(CI,0.54to0.86)fortheODI,0.52
(CI,0.05to0.80)fortheNDI,andfortheWOMAC0.70(CI,0.50to0.83).
Crossculturalvalidityandmeasurementinvariance
Withregardstocountrydifferences,threeitemsshowedstatisticallysignificantlevelsofDIF,allwith
largeeffectsizesaccordingtotheETSDeltascale[35],thesewereitems2(pain/stiffnessatnight;
lowerthanexpectedinUK–MH=8.54,p=0.04),12(understandingcondition;lowerthanexpected
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inDK-MH=11.37,p=0.01),and13(confidenceinmanaging;lowerthanexpectedinDK-MH=
15.21,p=0.001).Withregardstopainlocation,threeitemsshowedstatisticallysignificantlevelsof
DIF,items3,4and5.Item3(walking;hardestforlowerextremities,moderateforback/neckand
easiestforupperextremities-MH=38.71,adj.p<0.001),item4(washing/dressing;harderforupper
extremities,easierforlowerextremitiesandback/neck-MH=11.34,adj.p=0.04),item5(physical
activitylevels;easierforupperextremities,harderforlowerextremitiesandback/neck-MH=14.57,
adj.p=0.01).Withregardstoagegroup,paindurationandworkingstatus,noitemsexhibited
statisticallysignificantDIF.
Measurementerrorandreliability
Of134patientsintheDKcohortand165patientsintheUKcohortwithretestMSK-HQdataavailable,
98and82patientsreportedtheirconditiontobe‘stable’betweenbaselineandretest,respectively
andwerethususedtocalculatethereliabilitystatisticspresentedintable2.Whencomparedtothe
UKcohort,smallersystematicandrandomerrorswereobservedintheDanishcohortandICCvalues
wereslightlyhigher.Internalconsistencywashighforbothcohorts.Themedian(range)weighted
kappawithsquaredweightsacrossthe14itemsfortheDKcohortwas0.69(0.54to0.84)as
comparedto0.67(0.31to0.80)intheUKcohort.Detailsofthetest-retestreliabilityofsingleitemsof
theMSK-HQareavailableinAppendixA.
Sensitivitytochange,responsivenessandinterpretability
At12weeksfortheDKcohortmeanchangescoreswere9.1(95%CI,7.7to10.6);ES1.1(CI0.9to
1.2)fortheMSK-HQandmeanEQ-5D-5Lindexscoreswere0.08(CI,0.06to0.10);ES0.7(CI,0.5to
0.8).ThecorrespondingvaluesfortheUKcohortweremeanscore8.9(CI,7.4to10.5);ES0.9(CI,0.8
to1.1)fortheMSK-HQandfortheEQ-5D-5Lindexmeanscore0.11(CI,0.07to0.14);ES0.5(CI0.3
to0.6).Thecorrelations(SpearmanRho)betweenthetransitionquestionofchangeinmaincomplaint
andMSK-HQchangescoreswere-0.66(CI,-0.75to-0.55)and-0.54(CI,-0.65to-0.40)fortheDKand
UKcohorts,respectively.Table3presentstheROCanalysesandMCICestimatesaccordingtothetwo
cutpointsofpatientperceivedimportantchangeinmaincomplaint.Although,ROCAUCdiffered
betweentheDKandUKcohorts,thesedifferencesdidnotreachstatisticalsignificance.TheMCIC
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estimateforabsolutechangeat12weekswaslargerfortheDKcohort,whereasforthepercentages
ofchangetheoppositewastrue.ThepercentagesreachingtheMCICthresholdfor‘large
improvement’were48%intheDKcohortand47%intheUK-cohort,whereasthecorresponding
valuesfor‘smallimprovements’were57%and56%,respectively.Figure1illustratestheROC
curvesrepresentingchangescoresfortheMSK-HQascomparedtoEQ-5D-5Lindexat12weeks.For
bothcohortstheMSK-HQproducedhigherROCAUCsthantheEQ-5D-5L.FortheDKcohortthe
differencebetweenMSK-HQandEQ-5D-5LROCareasindexreachedborderlinestatisticalsignificance
forbothlargeimprovement(p=0.05)andsmallimprovement(p=0.06).
DiscussionThisisthefirststudytoevaluateandcomparemeasurementpropertiesofthenewMSK-HQtool
acrossdifferentinternationalcohortsofmusculoskeletalpatientsconsultingprimarycare
physiotherapyservices.TheMSK-HQwastranslatedandcross-culturaladaptedtoDanishspeaking
population.TheDanishversionoftheMSK-HQdemonstratedgoodfacevalidityandconstructvalidity
wasconfirmedbymoderatetostrongcorrelationswithrelevantreferencestandardmeasures.Inthe
DIFanalysisthreeitemsdisplayedmeasurementinvarianceforlanguage(pain/stiffnessatnight,
understandingcondition,confidenceinmanaging)andthreeforpainlocation(walking,
washing/dressing,physicalactivitylevels),whereasnodifferenceswereobservedforage,pain
durationandworkingstatus.ForbothcohortstheMSK-HQdemonstratedgoodinternalconsistency,
acceptablelevelsofreliabilityandresponsivenesswithreliabilitycoefficientsandROCestimates
exceeding0.70[15].
Thestudybenefittedfromprospectivelycollecteddataintwocomparablephysiotherapycohortswith
highcompletionratesonquestionnaires.Thestudyhadsomelimitations.Noformalsamplesize
calculationforthepresentstudywasperformed,butasbothcohortsexceededtheCOSMIN
recommendationsofatleast100individualsforquantitativePROMstudies[15],webelievethe
samplesizesofthetwocohortstobeadequate.Itshouldalsobenotedthatdataofthetwocohorts
wascollectedandadministrateddifferently.Thus,onlylimitedpopulationdescriptorsacrossthetwo
cohortswereavailable,withdatabeinglesscompleteinthecomparativeUKcohortforthevariables
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painsiteanddurationofsymptoms.ThequestionnairesintheUKcohortwerepaperbasedwhereas
questionnairesintheDKcohortwerecompletedonline.AsstudiescomparingpaperVs,online
administeredpatient-reportedoutcomemeasuresindicatethesetwoassessmentmethodsarehighly
comparable[39],itisunlikelytohaveaffectedourresults.
Thehighcompletionrate,acceptablefaceandconstructvalidityobservedconfirmedearlierpromising
findingsfromtheinitialvalidationstudy[14].IntermsofreliabilityandmeasurementserrortheDK
versionseemstoperformslightlybetterthantheUKversioninourstudy.Wealsoobserveda
significantlylargersystematicmeasurementerroroftest-retestscoresofMSK-HQfortheUKcohort.
Thesefindingsmay,inpart,beexplainedbydifferencesinstudydesigns.TheDKcohortpatients
completedtest-retestquestionnaireswitha6daysintervalbeforeanytreatmentwasinitiated,
whereaspatientsintheUKcohortcompleteditwithina2weeksinterval.Although,thesedifferences
werelevelledoutbyrestrictingtest-retestanalysisto‘stable’patientsonly,itispossiblethatthe
longertimeintervalcouldhaveresultedinmoreimprovementamong‘stable’patientsintheUK-
cohort.Itcouldbearguedthatrestrictinganalysisto‘stable’patientswouldinevitablyproducelower
MDCestimates,thanif'unstable'patientswereincluded.Howeverinourcase,ifallavailablepatients
hadbeenincludeditwouldonlyhaveincreasedtheMDCestimatebyapproximatelyonepoint(results
notshown),andthereforenothavechangedtheoverallconclusionofthestudy.Anotherlimitationof
thepresentstudywasthatclassificationofimprovedorunchangedpatientswerebasedonasingle
transitionscalequestionasexternalanchor(i.e.improvementinoverallcondition),whichmight
measurevaryingaspectsoftheoutcome[32].Theuseofseveralanchorscoveringdifferentaspects
oftheoutcome(e.g.pain,functionandpatientsatisfaction)mighthaveproducedotherresults.
Furthermore,notethatalternativemethodstoderiveMCICestimatesdoexist[40,41]howeverwe
chosetousetheROCcurvemethodtopreservecomparabilitywithotherstudiesinthefieldand
communicabilitywithreadersunfamiliarwithalternativemethods.
ThreeMSK-HQitemsexhibitedDIFacrosscountries.Item2‘pain/stiffness’atnightwasscoredlower
(i.e.morepain/stiffness)inUKpatientsalthoughnodifferenceswerefoundforthesimilaritem1
‘pain/stiffness’duringtheday.DKpatientshadloweritemscoreswithregardstounderstanding
13
conditionandconfidenceinmanaging(item12and13).Thesedifferencesmayeitherimply
translationalproblems,culturaldifferencesortruedifferencesbetweencohorts.Thisshouldbe
furtherinvestigatedthroughqualitativeinquiriestoexplorehowpatientsunderstandandinterpret
thesequestionsacrosscountries.Although,thesetwoitemsweredeemedimportantandrelevantby
patients,theyhavepreviouslyshowntocorrelatepoorlywiththetotalMSK-HQscore[14].Hence,it
couldbediscussedwhethertoincludetheseitemsintheoverallsumscoreortousethesequestions
separatelytofacilitatepatientcommunicationandsharedclinicaldecisionmaking.Thefindingsthat
noMSK-HQitemsdifferedforage,paindurationandworkingstatusaddstotheperviousresultsfrom
thevalidationstudyontheoriginalversion[14].Withregardstopainlocation,thelowerscoresfound
initem3‘walking’forextremitiesandback/neckpatients,whencomparedtoupperextremity
patientswasnotanunexpectedfinding,andseemsinlinewiththeoppositepatternforitem4
‘washing/dressing’.Itcouldbespeculatedthatthehigherscoresfoundforupperextremitiespatients
foritem5‘physicalactivitylevels’,maybeduetoexamplesgiven(goingforawalkorjogging),as
thesedonotincludedphysicalactivitiesrelatedtoupperextremities.Addingridingyourbikeor
playingtennis/golfcouldbeapotentialsolutiontothisdiscrepancybetweenpainsites.
Thedistinctionbetweenformative(i.e.,theitemscausetheconstruct)andreflective(i.e.,the
constructcausesthatwhichismeasuredbytheitems)toolsisnotalwayseasytomakeandtoolscan
exhibitaspectsofbothconceptualframeworks[42].Notethatpreviously,theMSK-HQhadbeen
consideredtobeaformativetoolhoweveronfurtherreflectionwefeelthattoolismuchbetter
characterisedasbeingreflective.ThemeasurementpropertyestimatesobservedfortheMSK-HQin
thepresentstudydidnotdifferfrommostexistingregion-specificPROMs[7,9,10,43]andgeneral
musculoskeletalPROMs[44].ForPROMs,reliabilitycoefficients≥0.7areconsideredadequatefor
groupcomparisons,whereas≥0.9areneededtomonitorindividualpatients[45].Similartomost
musculoskeletalPROMs,theMSK-HQonlyexceedthefirstmentionedthreshold,andtherefore,at
present,maybemostsuitableforgroupevaluation.MDCvaluesformusculoskeletalPROMsare
commonlyreportedtorangefrom10to20%ofthescale,whichisinlinewithourfindingsforthe
MSK-HQ.Toensurethatachangescoreonanindividualpatientlevelisclinicallyrelevant,theMCIC
14
shouldbegreaterthan,oratleastequalto,therandommeasurementerror(MDC)ofaninstrument.
ThiswasonlytrueintheDanishcohortofthepresentstudyandforthecut-off-leveloflarge
improvements,makingtheinterpretabilityofsmallchangesofindividualscoresoftheMSK-HQmore
challenging.AsMCICestimatesbasedonrelativescoreswereunaffectedbythecut-offlevelofthe
transitionquestionandrelativescoreshaveshowntobelesssensitivetobaselinescores[37];the
MCICpercentseemsthepreferablechoice.However,bothabsoluteandrelativeMCICvaluesvaried
betweenthetwocohorts.Thesedifferencesmaypartlyberootedintheuseofdifferentscalingof
transitionquestionofmaincomplaint(DKcohort7versus5responsecategories),whereastronger
correlationbetweenthetransitionquestionandMSK-HQchangescoresat12weekswasobserved.On
theotherhandtheproportionexceedingMCICthresholdsbetweentheDKcohortandUKcohortdid
notdiffersubstantially;largeimprovements(48%versus47%)andsmallimprovements(57%versus
55%).TheMSK-HQseemstodiscriminatewellbetweenunchangedandimprovedpatientsacrossthe
twocohorts.AkeyvisionoftheMSK-HQwastoproduceasinglebroadhealth-statusmeasuremore
sensitivetochangethangenerichealthtools.InbothcohortseffectsizesoftheMSK-HQwere
considerablylargerthanthoseoftheEQ-5D-5L,whichindicatessuperiorityoftheMSK-HQ.Whereas
fortheabilityofMSK-HQtodiscriminatebetweenimprovedandunchanged(i.e.responsiveness)a
patientat3months,superioritywasonlyobservedwithrespectintheDanishcohort.
ConclusionInthisstudyweperformedacross-countrycomparisonoftheMSK-HQquestionnaireamong
musculoskeletalpatientsconsultingprimarycarephysiotherapyservices.Although,somediscrepancy
forlanguageandpainsitelocationwasfoundforsingleitems,theMSK-HQgenerallyproduced
comparableresultsacrossthetwocohorts.TheDanishversionoftheMSK-HQappearstooutperform
theoriginalEnglishversionandhasshowntobeareliable,valid,sensitiveandresponsiveinstrument
tocaptureandmonitormusculoskeletalhealthstatus.
AbbreviationsMSK-HQ=TheMusculoskeletalHealthQuestionnaire
PROM=patientreportedoutcome
15
DIF=Differentialitemfunctioning
ICC=IntraclassCorrelationCoefficients
SEM=standarderrorofmeasurement
MDC=minimaldetectablechange
MCIC=Minimalclinicallyimportantchange
CI=Confidenceintervals
SD=standarddeviation
DeclarationsEthicsapprovalandconsenttoparticipate
TheDKcohortstudywasapprovedbyTheDanishDataProtectionAgency(Jno.1-16-02-542-16).
AccordingtoDanishlaw,approvalbytheethicscommitteeandwritteninformedconsentwasnot
required.Theeligiblepatientswereprovidedwithinformationaboutthestudyanditspurpose,
includingthatparticipationwasvoluntary.FortheUKcohortethicswasobtainedseparatelyfromthe
UKNHSHealthResearchAuthorityNationalResearchEthicsServiceCommittee(approvalreference:
15/YH/0167and15/WA/0040).
Consentforpublication
Notapplicable.
AvailabilityofDataandMaterials
DKcohortdatacannotbemadepubliclyavailableaccordingtoDanishregulations.Dataarehowever
availablefromtheauthorsuponreasonablerequestandpermissionoftheDanishDataProtection
Agency.FortheUKcohortadditionaldatacanbeaccessedonrequestviatheKeeledatarepository
at:http://www.keele.ac.uk/pchs/publications/datasharingresources/
CompetingInterests
Wedeclarenocompetinginterests
Funding
ThestudywassupportedbythePracticeResearchFoundationofDanishPhysiotherapistsand
ArthritisResearchUK(GrantRef.21405).
16
Authors’contribution
Allauthorsplannedanddesignedthestudy.DHCandGMperformedthestatisticalanalyses.DHC
draftedthemanuscript.Allauthorscontributedtointerpretationofdataandcriticalrevisionofthe
manuscript.Allauthorsreadandapprovedthefinalmanuscript.
Acknowledgments
Theauthorsthanktheclinicsthatparticipatedinthedatacollectionofthetwocohortstudiesand
patientsforparticipatinginthem.
References1. BriggsAM,CrossMJ,HoyDG,Sanchez-RieraL,BlythFM,WoolfAD,MarchL.
MusculoskeletalHealthConditionsRepresentaGlobalThreattoHealthyAging:A
Reportforthe2015WorldHealthOrganizationWorldReportonAgeingandHealth.
Gerontologist.2016;56Suppl2:S243-55.
2. BuchbinderR,vanTulderM,ObergB,CostaLM,WoolfA,SchoeneM,CroftP,Lancet
LowBackPainSeriesWorkingGroup.Lowbackpain:acallforaction.Lancet.
2018;391(10137):2384-2388.
3. CarrageeEJ,AlaminTF,MillerJL,CarrageeJM.Discographic,MRIandpsychosocial
determinantsoflowbackpaindisabilityandremission:aprospectivestudyin
subjectswithbenignpersistentbackpain.SpineJ.2005;5(1):24-35.
4. BedsonJ,CroftPR.Thediscordancebetweenclinicalandradiographicknee
osteoarthritis:asystematicsearchandsummaryoftheliterature.BMCMusculoskelet
Disord.2008;9:116-2474-9-116.
5. HartvigsenL,KongstedA,HestbaekL.Clinicalexaminationfindingsasprognostic
factorsinlowbackpain:asystematicreviewoftheliterature.ChiroprManTherap.
2015;23:13-015-0054-y.eCollection2015.
6. DawsonJ,DollH,FitzpatrickR,JenkinsonC,CarrAJ.Theroutineuseofpatient
reportedoutcomemeasuresinhealthcaresettings.BMJ.2010;340:c186.
17
7. AngstF,SchwyzerHK,AeschlimannA,SimmenBR,GoldhahnJ.Measuresofadult
shoulderfunction:DisabilitiesoftheArm,Shoulder,andHandQuestionnaire(DASH)
anditsshortversion(QuickDASH),ShoulderPainandDisabilityIndex(SPADI),
AmericanShoulderandElbowSurgeons(ASES)Societystandardizedshoulder
assessmentform,Constant(Murley)Score(CS),SimpleShoulderTest(SST),Oxford
ShoulderScore(OSS),ShoulderDisabilityQuestionnaire(SDQ),andWesternOntario
ShoulderInstabilityIndex(WOSI).ArthritisCareRes(Hoboken).2011;63Suppl
11:S174-88.
8. ChapmanJR,NorvellDC,HermsmeyerJT,BransfordRJ,DeVineJ,McGirtMJ,LeeMJ.
Evaluatingcommonoutcomesformeasuringtreatmentsuccessforchroniclowback
pain.Spine(PhilaPa1976).2011;36(21Suppl):S54-68.
9. SchellingerhoutJM,VerhagenAP,HeymansMW,KoesBW,deVetHC,TerweeCB.
Measurementpropertiesofdisease-specificquestionnairesinpatientswithneck
pain:asystematicreview.QualLifeRes.2012;21(4):659-670.
10. CollinsNJ,MisraD,FelsonDT,CrossleyKM,RoosEM.Measuresofkneefunction:
InternationalKneeDocumentationCommittee(IKDC)SubjectiveKneeEvaluation
Form,KneeInjuryandOsteoarthritisOutcomeScore(KOOS),KneeInjuryand
OsteoarthritisOutcomeScorePhysicalFunctionShortForm(KOOS-PS),KneeOutcome
SurveyActivitiesofDailyLivingScale(KOS-ADL),LysholmKneeScoringScale,Oxford
KneeScore(OKS),WesternOntarioandMcMasterUniversitiesOsteoarthritisIndex
(WOMAC),ActivityRatingScale(ARS),andTegnerActivityScore(TAS).ArthritisCare
Res(Hoboken).2011;63Suppl11:S208-28.
11. MoseS,ChristiansenDH,JensenJC,AndersenJH.Widespreadpain-dopainintensity
andcare-seekinginfluencesicknessabsence?-Apopulation-basedcohortstudy.
BMCMusculoskeletDisord.2016;17(1):197-016-1056-1.
18
12. SwiontkowskiMF,EngelbergR,MartinDP,AgelJ.Shortmusculoskeletalfunction
assessmentquestionnaire:validity,reliability,andresponsiveness.JBoneJointSurg
Am.1999;81(9):1245-1260.
13. KuorinkaI,JonssonB,KilbomA,VinterbergH,Biering-SorensenF,AnderssonG,
JorgensenK.StandardisedNordicquestionnairesfortheanalysisofmusculoskeletal
symptoms.ApplErgon.1987;18(3):233-237.
14. HillJC,KangS,BenedettoE,MyersH,BlackburnS,SmithS,DunnKM,HayE,ReesJ,
BeardD,Glyn-JonesS,BarkerK,EllisB,FitzpatrickR,PriceA.Developmentand
initialcohortvalidationoftheArthritisResearchUKMusculoskeletalHealth
Questionnaire(MSK-HQ)foruseacrossmusculoskeletalcarepathways.BMJOpen.
2016;6(8):e012331-2016-012331.
15. PrinsenCAC,MokkinkLB,BouterLM,AlonsoJ,PatrickDL,deVetHCW,TerweeCB.
COSMINguidelineforsystematicreviewsofpatient-reportedoutcomemeasures.Qual
LifeRes.2018;27(5):1147-1157.
16. TerweeCB,RoordaLD,DekkerJ,Bierma-ZeinstraSM,PeatG,JordanKP,CroftP,de
VetHC.MindtheMIC:largevariationamongpopulationsandmethods.JClin
Epidemiol.2010;63(5):524-534.
17. TerweeCB,BotSD,deBoerMR,vanderWindtAWM,KnolDL,DekkerJ,BouterLM,de
VetHC.Qualitycriteriawereproposedformeasurementpropertiesofhealthstatus
questionnaires.JClinEpidemiol.2007;60(1):34-42.
18. WildD,GroveA,MartinM,EremencoS,McElroyS,Verjee-LorenzA,EriksonP.
PrinciplesofGoodPracticefortheTranslationandCulturalAdaptationProcessfor
Patient-ReportedOutcomes(PRO)Measures:reportoftheISPORTaskForcefor
TranslationandCulturalAdaptation.ValueHealth.2005;8(2):94-104.
19. BrooksR.EuroQol:thecurrentstateofplay.HealthPolicy.1996;37(1):53-72.
19
20. JanssenMF,PickardAS,GolickiD,GudexC,NiewadaM,ScaloneL,SwinburnP,
BusschbachJ.MeasurementpropertiesoftheEQ-5D-5LcomparedtotheEQ-5D-3L
acrosseightpatientgroups:amulti-countrystudy.QualLifeRes.2013;22(7):1717-
1727.
21. vanHoutB,JanssenMF,FengYS,KohlmannT,BusschbachJ,GolickiD,LloydA,
ScaloneL,KindP,PickardAS.InterimscoringfortheEQ-5D-5L:mappingtheEQ-5D-
5LtoEQ-5D-3Lvaluesets.ValueHealth.2012;15(5):708-715.
22. SchonnemannJO,EggersJ.ValidationoftheDanishversionoftheQuick-Disabilities
ofArm,ShoulderandHandQuestionnaire.DanMedJ.2016;63(12):A5306.
23. BudtzCR,AndersenJH,deVosAndersenNB,ChristiansenDH.Responsivenessand
minimalimportantchangeforthequick-DASHinpatientswithshoulderdisorders.
HealthQualLifeOutcomes.2018;16(1):226-018-1052-2.
24. LauridsenHH,HartvigsenJ,MannicheC,KorsholmL,Grunnet-NilssonN.Danish
versionoftheOswestryDisabilityIndexforpatientswithlowbackpain.Part1:
Cross-culturaladaptation,reliabilityandvalidityintwodifferentpopulations.Eur
SpineJ.2006;15(11):1705-1716.
25. LauridsenHH,HartvigsenJ,MannicheC,KorsholmL,Grunnet-NilssonN.Danish
versionoftheOswestrydisabilityindexforpatientswithlowbackpain.Part2:
Sensitivity,specificityandclinicallysignificantimprovementintwolowbackpain
populations.EurSpineJ.2006;15(11):1717-1728.
26. LauridsenHH,O'NeillL,KongstedA,HartvigsenJ.TheDanishNeckDisabilityIndex:
NewInsightsintoFactorStructure,Generalizability,andResponsiveness.PainPract.
2016.
27. RoosEM,RoosHP,LohmanderLS,EkdahlC,BeynnonBD.KneeInjuryand
OsteoarthritisOutcomeScore(KOOS)--developmentofaself-administeredoutcome
20
measure.JOrthopSportsPhysTher.1998;28(2):88-96.
28. KlassboM,LarssonE,MannevikE.Hipdisabilityandosteoarthritisoutcomescore.An
extensionoftheWesternOntarioandMcMasterUniversitiesOsteoarthritisIndex.
ScandJRheumatol.2003;32(1):46-51.
29. NilsdotterAK,LohmanderLS,KlassboM,RoosEM.Hipdisabilityandosteoarthritis
outcomescore(HOOS)--validityandresponsivenessintotalhipreplacement.BMC
MusculoskeletDisord.2003;4:10.
30. FayersPM,MachinD.QualityofLife:Theassesment,analysisandinterpretationof
patient-reportedoutcomes:2nded.WestSussex,England:JohnWiley&SonsLtd;
2007.
31. CohenJ.Statisticalpoweranalysisforthesocialsciences.2nded.Hillsdale,NJ:
LaurenceErlbaum;1998.
32. RevickiD,HaysRD,CellaD,SloanJ.Recommendedmethodsfordetermining
responsivenessandminimallyimportantdifferencesforpatient-reportedoutcomes.J
ClinEpidemiol.2008;61(2):102-109.
33. RCoreTeam.R:Alanguageandenvironmentforstatisticalcomputing.R
FoundationforStatisticalComputing,Vienna,Austria.
.2018.http://www.R-project.org/.Accessed07/012018.
34. MagisD,BelandS,TuerlinckxF,DeBoeckP.AgeneralframeworkandanRpackage
forthedetectionofdichotomousdifferentialitemfunctioning.BehavResMethods.
2010;42(3):847-862.
35. DoransNJ,HollandPW.DIFDETECTIONANDDESCRIPTION:MANTEL‐HAENSZELAND
STANDARDIZATION1,2.ETS.ResearchReportSeries.1992(1):pp.i-40.ly.
36. FroudR,AbelG.UsingROCcurvestochooseminimallyimportantchangethresholds
whensensitivityandspecificityarevaluedequally:theforgottenlessonof
21
pythagoras.theoreticalconsiderationsandanexampleapplicationofchangein
healthstatus.PLoSOne.2014;9(12):e114468.
37. FrahmOlsenM,BjerreE,HansenMD,TendalB,HildenJ,HrobjartssonA.Minimum
clinicallyimportantdifferencesinchronicpainvaryconsiderablebybaselinepain
andmethodologicalfactors:systematicreviewofempiricalstudies.JClinEpidemiol.
2018.
38. DeLongER,DeLongDM,Clarke-PearsonDL.Comparingtheareasundertwoormore
correlatedreceiveroperatingcharacteristiccurves:anonparametricapproach.
Biometrics.1988;44(3):837-845.
39. GwaltneyCJ,ShieldsAL,ShiffmanS.Equivalenceofelectronicandpaper-and-pencil
administrationofpatient-reportedoutcomemeasures:ameta-analyticreview.Value
Health.2008;11(2):322-333.
40. TerluinB,EekhoutI,TerweeCB.Theanchor-basedminimalimportantchange,based
onreceiveroperatingcharacteristicanalysisorpredictivemodeling,mayneedtobe
adjustedfortheproportionofimprovedpatients.JClinEpidemiol.2017;83:90-100.
41. TerluinB,EekhoutI,TerweeCB,deVetHC.Minimalimportantchange(MIC)basedon
apredictivemodelingapproachwasmoreprecisethanMICbasedonROCanalysis.J
ClinEpidemiol.2015;68(12):1388-1396.
42. deVetHC,TerweeCB,MokkinkLB,KnolDL,.Measurementinmedicine:apractical
guide.CambridgeUniversityPress.;2011.
43. ChiarottoA,MaxwellLJ,TerweeCB,WellsGA,TugwellP,OsteloRW.Roland-Morris
DisabilityQuestionnaireandOswestryDisabilityIndex:WhichHasBetter
MeasurementPropertiesforMeasuringPhysicalFunctioninginNonspecificLowBack
Pain?SystematicReviewandMeta-Analysis.PhysTher.2016;96(10):1620-1637.
44. BouffardJ,Bertrand-CharetteM,RoyJS.Psychometricpropertiesofthe
22
MusculoskeletalFunctionAssessmentandtheShortMusculoskeletalFunction
Assessment:asystematicreview.ClinRehabil.2016;30(4):393-409.
45. FayersPM,MachinD.Scoresandmeasurements:validity,reliability,sensitivity.In:
AnonymousQualityofLife:Theassessment,analysisandinterpretationofpatient
reportedoutcomes.WestSussex,England:JohnWiley&SonsLtd;2007.
TablesTable1.Patientcharacteristics
VariablesDKcohort(n=153) UKcohort
(n=166)
Painsite
Back 45 (29.4) 47 (28.3)Neck 23 (15.0) 7 (4.2)Upperextremity 38 (24.8) 35 (21.1)Lowerextremity 47 (30.7) 57 (34.3)Other/unknown - - 20 (12.0)
Gender
Woman 97 (63.4) 92 (55.4)Men 56 (36.6) 74 (45.6)
Age
Yearsmean,(SD) 50.4 (13.8) 53.7 (15.7)
Workstatus
Working 96 (62.8) 94 (56.6)Notworking/Subsidedjob 6 (3.9)
7 (4.2)
Notworking/unemployed 14 (9.2)
5 (3.0)
Retired 26 (17.0) 52 (31.1)Onsickleave 11 (7.2) 7 (4.2)
Unknown - - 1 (0.1)
Durationofsymptoms
≤3months 62 (40.5) 77 (47.2)>3months 91 (59.4) 66 (39.8)Unknown - - 23 (13.9)
Baselinescore
MSK-HQ(0to56)mean,(SD) 32.3 (9.2)
30.5 (9.64)
EQ-5D-5Lindex(-0.6to1.0)mean,(SD) 0.69 (0.16)
0.55 (0.25)
Valuesarenumbers(percentages)unlessstatedotherwise.
Abbreviations:SD,standarddeviation
23
Table2.MeasurementerrorandreliabilityofMSK-HQscoresfortheDKcohortandtheUKcohort
DK-cohort
(n=98)UK-cohort
(n=82)Measurementerror
MeanDifference(95%CI) 1.6 (0.7to2.5) 3.9 (2.7to5.1)
SEM(95%CI) 3.1 (2.7to3.6) 3.6 (3.1to4.1)
MDC(95%CI) 8.6 (7.6to10.1) 9.9 (8.7to11.3)
Reliability
ICC(95%CI) 0.86 (0.81to0.91) 0.80 (0.50to0.90)
Cronbach’sα(Baseline) 0.88 (0.85to0.91) 0.89 (0.86to0.89)
Abbreviations:CI,Confidenceinterval;SEM,Standarderrorofthemeasurement;MDC,MinimalDetectableChange;
Table3.ROCandMCICestimatesaccordingtopatientperceivedimportantchangeinmaincomplaint
Cutpoints n(%) ROCAUC(95%CI) MCICROCSensitivity/
specificity%
Largeimprovement
DKcohort 64(52.5)0.83(0.75to
0.90) 10 78/81
UKcohort 49(37.1)0.79(0.71to
0.87) 8 78/69
Smallimprovement
DKcohort 87(74.3)0.85(0.77to
0.92) 8 76/80
UKcohort 85(64.9)0.76(0.68to
0.85) 6 71/71
a)Largeimprovement(muchbetter,betterversusalittlebetter,unchanged,littleworse)
b)Smallimprovements(muchbetter,better,littlebetterversusunchanged)
MCICROC:Estimatedastheoptimalcut-offpointoftheROCcurveusingabsolutechangescores.
MCICpercent:Estimatedastheoptimalcut-offpointoftheROCcurveusingrelativechangescores.
Abbreviations:ROC,receiveroperatingcharacteristic;AUC,areaunderthecurve;CI,confidenceinterval.Appendix
24
AppendixATest-retestreliabilityofsingleitemsoftheMSK-HQfortheDKandUKcohort
Item QuestionDKcohort(n=98)
UKcohort(n=82)
1 Pain/stiffnessduringtheday 0.73(0.63to0.81) 0.55(0.62to0.84)
2 Pain/stiffnessatnight 0.58(0.48to0.69) 0.68(0.55to0.78)
3 Walking 0.84(0.76to0.90) 0.74(0.62to0.84)
4 Washing/Dressing 0.64(0.44to0.80) 0.66(0.51to0.78)
5 Physicalactivitylevels 0.76(0.66to0.84) 0.69(0.56to0.79)
6 Work/dailyroutine 0.82(0.74to0.88) 0.61(0.48to0.71)
7 Socialactivitiesandhobbies 0.56(0.41to0.68) 0.59(0.43to0.73)
8 Needinghelp 0.78(0.66to0.87) 0.78(0.69to0.85)
9 Sleep 0.75(0.62to0.84) 0.80(0.71to0.87)
10 Fatigueorlowenergy 0.77(0.64to0.85) 0.75(0.63to0.83)
11 Emotionalwell-being 0.57(0.43to0.71) 0.78(0.69to0.85)
12 Understandingcondition 0.54(0.38to0.69) 0.31(0.13to0.48)
13 Confidenceinmanaging 0.58(0.45to0.70) 0.49(0.25to0.69)
14 Overallimpact 0.62(0.47to0.73) 0.58(0.43to0.69)
Valuesareweightedkappawithsquaredweights(95%Confidenceintervals)
Figures
25
Figure1
Receiver-operating-characteristic(ROC)curvesrepresentingabsolutechangescoresofthe
MSK-HQandEQ-5D-5LFootnoteValuesareROCareaestimates(95%confidenceintervals).