University of Groningen. Active ageing and quality of life Bielderman, Johanne Henrike

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1 University of Groningen Active ageing and quality of life Bielderman, Johanne Henrike IMPORTANT NOTE: You are advised to consult the publisher's version (publisher's PDF) if you wish to cite from it. Please check the document version below. Document Version Publisher's PDF, also known as Version of record Publication date: 2016 Link to publication in University of Groningen/UMCG research database Citation for published version (APA): Bielderman, J. H. (2016). Active ageing and quality of life: Community-dwelling older adults in deprived neighbourhoods [Groningen]: Rijksuniversiteit Groningen Copyright Other than for strictly personal use, it is not permitted to download or to forward/distribute the text or part of it without the consent of the author(s) and/or copyright holder(s), unless the work is under an open content license (like Creative Commons). Take-down policy If you believe that this document breaches copyright please contact us providing details, and we will remove access to the work immediately and investigate your claim. Downloaded from the University of Groningen/UMCG research database (Pure): For technical reasons the number of authors shown on this cover page is limited to 10 maximum. Download date:

2 Chapter2 AnnemiekBielderman,CeesPvanderSchans,MarieRoseJvanLieshout MathieuHGdeGreef,FroukjeBoersma,WimPKrijnen,NardiSteverink BMCgeriatrics2013,13(1):86.

3 Chapter2 2 ABSTRACT Background Due to the rapidly increasing number of older people worldwide, the prevalenceoffrailtyamongolderadultsisexpectedtoescalateincomingdecades.itis crucialtorecognizeearlyonsetsymptomstoinitiatespecificpreventivecare.therefore, earlydetectionoffrailtywithappropriatescreeninginstrumentsisneeded.theaimof thisstudywastoevaluatetheunderlyingdimensionalityofthegroningenfrailtyindicator (GFI),awidelyusedselfreportscreeninginstrumentforidentifyingfrailolderadults.In addition,criterionvalidityofgfisubscaleswasexaminedandcompositionofgfiscores wasevaluated. Methods A crosssectional study design was used to evaluate the structural validity, internalconsistencyandcriterionvalidityofthegfiquestionnaireinolderadultsaged65 yearsandolder.allsubjectscompletedthegfiquestionnaire(n=1508).toassesscriterion validity, a smaller sample of 119 older adults completed additional questionnaires: De Jong Gierveld Loneliness Scale, Hospital Anxiety Depression Scale, RAND36 physical functioning, and perceived general health item of the EuroQol5D. Exploratory factor analysisandmokkenscaleanalysiswereusedtoevaluatethestructuralvalidityofthegfi. AVenndiagramwasconstructedtoshowthecompositionofGFIsubscalescoresforfrail subjects. Results The factor structure of the GFI supported a threedimensional structure of the scale. The subscales Daily Activities and Psychosocial Functioning showed good internal consistency,scalability,andcriterionvalidity(dailyactivities:cronbach s=0.81,h s=.84, r=.62;psychosocialfunctioning:cronbach s=0.80,h s=.35,r=.48).thesubscale Health Problems showed less strong internal consistency but acceptable scalability and criterionvalidity(cronbach s=.57,h s=.35,r=.48).thepresentdatasuggestthat90% ofthefrailolderadultsexperienceproblemsinthepsychosocialfunctioningdomain. ConclusionsThepresentfindingssupportathreedimensionalfactorstructureoftheGFI, suggestingthatamultidimensionalassessmentoffrailtywiththegfiispossible.thesegfi subscalescoresproducearicherassessmentoffrailtythanwithasingleoverallsumgfi score,andlikelytheirusewillcontributetomoredirectedandcustomizedcareforolder adults. 22

4 PsychometricpropertiesoftheGroningenFrailtyIndicator BACKGROUND Frailtyischaracterizedbyadeclineinreservecapacityindifferentdomainsoffunctioning, resultinginadeclineinmobility,unintendedweightloss,anelevatedriskofmorbidity,an increaseindepressionandanxiety,institutionalization,andprematuredeath[1,2].dueto therapidlyincreasingnumberofolderpeopleworldwide,theprevalenceoffrailtyamong older adults is increasing and expected to escalate in coming decades [3,4]. In order to preventthedetrimentalconsequencesoffrailty,likethelossofbalanceandthedecrease inmusclestrengthandwalkingspeed,itiscrucialtorecognizeearlyonsetsymptomsand theninitiateappropriatecareandspecificpreventiveinterventions.anumberofreview studies have shown that several interventions may be beneficial for older adults in differentstagesoffrailty[58]. Early detection of frailty in older adults is feasible with appropriate screening instruments. These screening instruments measure frailty in various ways [9]. Some measurements are based on a clinical assessment by a geriatrician others use performancebased tests or selfreport questionnaires. A number of frailty assessment instrumentshaveemergedinthelastdecade[1,923].theseinstrumentsaredesignedto screen older adults in a valid and feasible way. The majority of these screening instruments include items on physical frailty characteristics like mobility and nutritional status. Only some instruments include items in multiple frailty domains, like the Frailty Index,theGroningenFrailtyIndicator,theTilburgFrailtyIndicatorandtheEdmuntonFrail Scale[9].Especiallyfrailtyinstrumentsusedforcasefindingandscreening,evaluatefrailty dichotomously: persons are considered as either frail or not frail, regardless of the multipledimensionsmeasuredbytheinstrument[9]. One of these multidimensional screening instruments is the Groningen Frailty Indicator (GFI). The GFI is a widely used screening instrument for identifying frail older adults [22,24]. The GFI consists of 15 selfreport items and is a feasible way to assess frailty in both communitydwelling and institutionalized older people [25,26]. PsychometricstudiesexaminingtheoverallinternalconsistencyoftheGFIshowarangeof Cronbach'svalues,from=0.68to=0.73,indicatingmoderateinternalconsistency [2527].Besidesfeasibilityandreliability,theconstructanddiscriminantvalidityoftheGFI wereexaminedinpreviousresearch[26]. However,theGFIisbeingusedasaonedimensionalscalebasedonanoverall sum score of 15 items. A person is considered to be frail when the GFI sum score is 4 points or higher [26,27].The sum score is used as a homogeneous indicator of frailty, without reference to specific problems like sensorimotor functioning, cognitive functioning, mobility, or psychosocial functioning. Consequently, a variety of different frailtyrelatedproblemscanleadtoasumscoreof4points.webelievethatthegfihas the potential to provide more differentiated information about the salience of specific frailtyrelatedproblems,andthusdirectamoreadequatelyfocusedprogramforthecare 2 23

5 Chapter2 2 and support frail older adults need. For this reason, an assessment of the various dimensionsoffrailtyisobviouslyneeded. Themainobjectiveofthisstudywastoevaluatetheunderlyingdimensionalityof the GFI questionnaire for screening frailty in communitydwelling older persons. In addition, we examined the criterion validity of the GFI subscales. Furthermore, we evaluatedthecompositionofgfisubscalescoresforsubjectsidentifiedasfrailbasedon thecurrentlyusedcutoffscoreof4points. METHODS Studydesign A crosssectional study design was used to evaluate the structural validity and criterion validityofthegfiquestionnaireinolderadultsaged65yearsandolder.inthisstudy,data ofolderadultslivinginasmallcityinacentrallylocatedregionofthenetherlandswere used(n=1508).inasmallersample(n=119),weexaminedthecriterionvalidityofthe GFIsubscales. Studysampleanddatacollection In 2008, 3083 older adults (65 years and older) were approached by their local health authoritiestofillinthegfiquestionnaire.besides,asmallersampleof200olderadults wasapproachedbycommunitycenterstofillinthegfiandadditionalquestionnaires.in total, 1508 persons completed the GFI and 119 persons completed the additional questionnaires.underdutchlegislation,ethical approvalwasnotrequired inthiscross sectionalnonobtrusiveobservationalstudy.allsubjectsgavetheirconsenttoparticipate inthestudy. Measures GFI TheGFIisa15itemscreeninginstrumentusedtodeterminetheleveloffrailty[22].Eight itemshavetworesponsecategories(yes/no),sixitemshavethreeresponsecategories (yes/sometimes/no),andoneitemhasalikertresponsecategory(110).allitemswere dichotomizedtocalculategfisumscores.ahighergfisumscoreindicatesagreaterlevel offrailty,withamaximumscoreof15.thegfiisdisplayedinappendix1. Toexaminecriterionvalidity,weusedfouradditionalscalesorsubscales:DeJong Gierveld Loneliness Scale [28], Hospital Anxiety Depression Scale (HADS) [29], physical functioningsubscaleoftherand36[30],andtheperceivedgeneralhealthitemofthe EuroQol5D[31]. 24

6 PsychometricpropertiesoftheGroningenFrailtyIndicator DeJongGierveldLonelinessscale The6itemDeJongGierveldscalewasusedtomeasureloneliness[28].This6itemLikert scale is a reliable and valid instrument for measuring overall, emotional, and social lonelinessinlargesurveysofolderadults(cronbach s= )[32].allitemshave fiveresponsecategories(no!/no/moreorless/yes/yes!).afterrecoding,higherscores indicategreaterlevelsofloneliness. HADS TheDutchversionofthe14itemHADSwasusedtoassessthepresenceofanxietyand depressive states independent of coexisting general medical conditions [29]. The HADS consistsofananxietysubscale(7items)andadepressionsubscale(7items).inageneral population aged 65 years and over, the reliability of both the anxiety and depression subscalesasthetotalscalevariedwithcronbach svaluesbetween0.71and0.8[29]. Higherscoresrepresentgreateranxietyand/ormoredepressivesymptoms. 2 RAND36 Selfreported physical functioning was assessed using the 10item physical functioning subscaleofthedutchrand36itemhealthsurvey(rand36).therand36isareliable andvalidscaleformeasuringdifferentaspectsofhealthindifferentagegroups[30,33]. The overall scale contains eight subscales: physical functioning, social functioning, role limitations caused by physical health problems, role limitations caused by emotional problems, mental health, vitality, bodily pain, and general health perceptions [30]. The physicalfunctioningsubscaleisareliableandvalidscaleformeasuringlimitationsindaily activitiesduetohealthproblems(cronbach s=0.92)[30].therespondentreportsto what extent he feels limited in a particular activity (limited a lot / limited a little / not limitedatall).rawscoresaretransformedintoindexscoresrangingfrom0to100.after transformation, lower scores on the physical functioning subscale indicate more limitationsinactivitiesofdailyliving. EuroQol5D PerceivedgeneralhealthwasassessedonaLikertscaleof1to10,where10represents excellent general health. This item represents one item in the overall EuroQol5D questionnaire[31]. Statisticalanalyses Descriptive statistics were used to report subject characteristics of the study sample. Structuralvalidityisdefinedasthedegreetowhichthescoresareanadequatereflection of the dimensionality of the construct to be measured [34]. Structural validity was assessed using exploratory factor analysis. Exploratory principal component analysis 25

7 Chapter2 2 followedbyobliquerotationaccordingtothedirectoblimincriterionwasconductedto explorefactorstructure.thenumberoffactorswasbasedonthescreeplotevaluation, the size of the eigenvalues, and their confidence intervals. All factors with eigenvalues greaterthanonewereretained.incaseanitemdidnotdiscriminatewellbetweenfactors, decisionsweremadebasedonthecontentoftheitemandtheresultsofthereliability analysisofthesubscales.reliabilityofthefactorsolutionwasdeterminedbycalculating internalconsistencyusingcronbach swithcorresponding95%confidenceintervals(ci). ACronbach scoefficientof0.80wasconsidered good, acceptable, questionable, poor, and<0.50 unacceptable [35,36]. In addition, scale analysis of the GFI was applied using Mokken item response theory model of monotone homogeneity [37]. Mokken scale analysis tests the homogeneity of the subsets of items of test batteries that are multidimensional by construction[38].aloevinger sscalabilitycoefficient(h)of indicatesaweak scale,h indicatesamoderatescale,andh0.50indicatesastrongscale[39]. Criterion validity is defined as the degree to which the scores are anadequate reflection of a gold standard [34]. To establish criterion validity of the observed GFI subscales,thegfisubscaleswerecomparedtorelatedreliableandvalidscalesconsidered to be gold standards of the individual dimensions. Positive relations were hypothesized between GFI subscale Psychosocial Functioning and HADS and the Jong Gierveld Loneliness scale. Negative relations were hypothesized between GFI subscale Daily Activities and RAND36 physical functioning scale, and between GFI subscale Health Problems and Perceived general health (EuroQol5D). Pearson correlations (twotailed) between GFI subscales and related scales were calculated. A correlation of <0.30 was considered low, moderate, and>0.60 high [40]. AVenndiagramwasconstructedtoshowthecompositionofGFIsubscalescores forallsubjectsidentifiedasfrailbasedonthecurrentlyusedcutoffscoreof4points.the diagramprovidesinformationaboutthecompositionofascoreof4(ormore)points.only subjectsthatperceivedproblemsin25%oftheitemsofeachsubscalearerepresentedin thevenndiagram.differencesbetweenthegroupswithinthevenndiagramweretested byusingthechi 2 testforcategoricaldataandanovatestforcontinuousdata. For frail older adults, frequency distributions for different age groups were calculated and tested for dependencies by using the Chi 2 test and estimation of a log linearmodel.weusedthefactorsindicatingage(incategories)andperceivedproblemsin the subscales Daily Activities, Psychosocial Functioning, and Health Problems (score on 25%ofthesubscaleitems).Toincreasepower,wetreatedthelattervariablesasordinals. Data from subjects were excluded from further analyses when more than five items (30%) of the GFI were missing. In total, 17 persons were excluded from further analysesbecauseofmissingdataonthegfi.intheanalyzedsample,1277personshadno missingdataatall,194personshadonemissingvalue,27personshadtwomissingvalues, 26

8 PsychometricpropertiesoftheGroningenFrailtyIndicator 4personshadthreemissingvaluesand6personshadfourorfivemissingvaluesonthe GFI. These remaining missing values were imputed by the logistic regression data imputationmethod[41]. Data were processed using the statisticalsoftwarespssstatistics19(spssinc., Chicago,IL,USA)andtheRstatisticalprogrammingsystem(RDevelopmentCoreTeam, 2011).Statisticalsignificancelevelwassettop=0.05. RESULTS Participants Atotalof1508personsparticipatedinthestudy.Ageoftherespondentsrangedfrom65 to97years,withamean(sd)ageof75(7)years;49.3%werefemale,and41.7%were livingalone.table1showsthecharacteristicsofallparticipants. 2 Table1Characteristicsoftheparticipants(n=1508). Overallsample (n=1508) Mainsample (n=1389) Smallersample (n=119) t(df) or Chi 2 (df) Meanage(y)SD (135.5) <0.001* Agegroups,n(%) 65 69y 418(29.2) 392(29.8) 26(21.8) 20.01(4) <0.001* 70 74y 363(25.3) 344(26.2) 19(16) 75 79y 301(21.0) 274(20.9) 27(22.7) 80 84y 206(14.4) 181(13.8) 25(21) >84y 145(10.1) 123(9.4) 22(18.5) Gender,n(%) Male 730(50.7) 695(52.7) 35(29.4) 30.81(2) <0.001* Female 709(49.3) 625(47.3) 84(70.6) Educationallevel,n(%) Low 644(47.1) 582(46.4) 62(55.4) 5.47(2) Middle 507(37.1) 467(37.2) 40(35.7) High 216(15.8) 206(16.4) 10(8.9) Livingsituation,n(%) Livingtogether 848(58.3) 807(60.4) 41(34.7) 29.37(1) <0.001* Singleliving 606(41.7) 529(39.6) 77(65.3) GFI,meanSD (1506) GFI=GroningenFrailtyIndicator. *Valuesarepercentagesunlessindicatedotherwise. Independentttestresults. 2 Chi testresults. *p<0.05. p 27

9 Chapter2 2 AscanbeseeninTable1,thesmallersampledifferedfromthemainsampleinmeanage, gender,andlivingsituation.comparedtothemainsample,thesmallersampleconsisted of persons with a higher average age (77 vs 74 years), relatively more females (71% vs 47%)andmoresinglelivingpersons(65%vs40%).EducationallevelandGFItotalscoresof thesmallersampledidnotdiffersignificantlyfromthemainsample. FactorstructureoftheGFI Table 2 shows the factor loadings after oblimin rotation and eigenvalues from the principalcomponentanalysis.evaluationofthescreeplotandthesizeoftheeigenvalues stronglysuggestthatthegfihasathreedimensionalstructure,explaining50.6%ofthe variance. This analysis produced three subscales: (1) Daily Activities (items 14), (2) PsychosocialFunctioning(items1115),and(3)HealthProblems(items510). The rotated factors did not clearly discriminate item 5 ( How do you rate your physical fitness? ). Based on content and reliability analysis, this item was assigned to factor3(subscalehealthproblems).cronbach salphadecreased(from.81to.77)when Table2FactorloadingsandeigenvaluesfromtheprincipalcomponentanalysisoftheGFIscale(n= 1508). Factor* Daily Activities Psychosocial Functioning Health Problems 1.Shopping Walkingoutdoors Dressingandundressing Goingtothetoilet Physicalfitness Visionproblems Hearingproblems Unintentionalweightloss Useofmorethanthreemedicines Memorycomplaints Experienceofemptiness Missingpeoplearound Feelingabandoned Feelingsad/dejected Feelingnervous/anxious.598 Initialeigenvalues(95%CI) 4.42 ( ) 1.99 ( ) 1.18 ( ) Cumulativevariance(%) GFI=GroningenFrailtyIndicator;CI=confidenceinterval. *Factorloadings<0.30arenotpresented,exceptforitem5.Boldloadingscorrespondtothesubscales. 28

10 PsychometricpropertiesoftheGroningenFrailtyIndicator item5wasassignedtofactor1(subscaledailyactivities),andincreased(from.47to.57) whenitem5wasassignedtofactor3(subscalehealthproblems). The GFI subscales Daily Activities and Psychosocial Functioning showed good internal consistency, with Cronbach s= 0.81 (95% CI = ) and Cronbach s= 0.80(95%CI= ),respectively.Bycontrast,thesubscaleHealthProblemsshowed a poor internal consistency (Cronbach s = 0.57; 95% CI = ). In all subscales, Cronbach sdecreasedwhenanyoftheitemsweredeleted. ScaleanalysisofGFIsubscales Table3showsthescalingcoefficients(H)fromtheMokkenscaleanalysesforeachofthe GFIsubscales.ThesubscalesDailyActivitiesandPsychosocialFunctioningwereidentified asstrongscales,withh s=0.84andh s=0.54,respectively.ontheotherhand,thesubscale HealthProblemswasidentifiedasaweakscale(H s=0.35). 2 Table3ScalingcoefficientsfromMokkenscaleanalysesforitemsoftheGFIsubscales(n=1508). Item DailyActivities (item14) HealthProblems (item510) Hi(95%CI)* Hi(95%CI) Hi(95%CI) PsychosocialFunctioning (item1115) ( ) 0.40( ) 0.57( ) ( ) 0.34( ) 0.56( ) ( ) 0.28( ) 0.58( ) ( ) 0.30( ) 0.51( ) ( ) 0.47( ) ( ) Hs 0.84( ) 0.35( ) 0.54( ) Hi,=scalingcoefficientofitem;Hs=scalingcoefficientoftotalsubscale; GFI=GroningenFrailtyIndicator;CI=confidenceinterval. *InterpretationLoevinger sscalingcoefficients:hsof indicatesaweakscale;hsof indicatesamoderatescale;hs>0.50indicatesastrongscale. CriterionvalidityofGFIsubscales WeassessedthecriterionvalidityofGFIsubscalesbycalculatingcorrelationcoefficients among the subscales and four related scales (Jong Gierveld Loneliness Scale, HADS, physicalfunctioningsubscaleoftherand36,hads,andperceivedgeneralhealthitemof theeuroqol5d)(seetable4).thesubscaledailyactivitieswasstronglycorrelatedwith therand36physicalfunctioningscale(r=0.62).thesubscalepsychosocialfunctioning wasstronglycorrelatedwiththehads(r=0.67)andthejonggierveldlonelinessscale(r= 0.67).ThesubscaleHealthProblemswasmoderatelycorrelatedwiththegeneralhealth rating of the EuroQol5D (r = 0.48). Furthermore, moderate correlations were found betweenthehealthproblemssubscaleandtherand36physicalfunctioning(r=0.53), thehads(r=0.36),andthejonggierveldlonelinessscale(r=0.37).theratingofgeneral 29

11 Chapter2 2 Table4PearsoncorrelationsbetweentheGFIsubscalesandrelatedscales(n=119). RAND36Physical Functioning Perceivedgeneral health(euroqol5d) HADS DeJongGierveld Lonelinessscale GFIsubscale: r(95%ci) r(95%ci) r(95%ci) r(95%ci) DailyActivities HealthProblems Psychosocial Functioning 0.617* ( ) ( ) ( ) ( ) 0.480* ( ) ( ) ( ) ( ) ( ) ( ) 0.668* 0.671* ( ) ( ) GFI=GroningenFrailtyIndicator;HADS=HospitalAnxietyandDepressionScale;CI =confidenceinterval. *Boldloadingsrepresentrelatedscales. PerceivedgeneralhealthitemoftheEuroQol5Dquestionnaire. health was moderately correlated with all three GFI subscales Daily Activities, Health Problems,PsychosocialFunctioning(r=0.31,r=0.48,r=0.44,respectively). CompositionofGFIscoreforfrailsubjects Figure1givesaVenndiagramrepresentationofthedistributionofthesubscalescoresfor all subjects with a total GFI score of4 (N = 540). For about one quarter of the frail subjects(26.9%),thegfiscorewasexclusivelycomposedofperceivedproblemsinone domain.injustalimitednumberofsubjects,thegfiscorewasexclusivelycomposedof perceivedproblemsinthedailyactivitiesdomain(0.9%)orthehealthproblemsdomain (4.1%).For21.9%ofthefrailsubjects,thePsychosocialFunctioningdomaincontributed exclusivelytothegfiscores. DailyActivities =1of4items GFI>=4 N= % N=5 3.0% N=16 5.5% N= % N= % N=118 Figure1VenndiagramofthefrequencydistributionofsubscalescoresforpersonswithatotalGFI score4(n=540). 35.7% N=193 Psychosocial Functioning =2of5items 4.1% N=22 HealthProblems =2of6items 30

12 PsychometricpropertiesoftheGroningenFrailtyIndicator For almost half of the frail subjects (44.3%), the GFI score was composed of perceived problems in two domains. In only a limited number of subjects, the GFI score was composedofproblemsinboththedailyactivitiesandpsychosocialfunctioningdomains (3.0%),orcomposedofboththeDailyActivitiesandHealthProblemsdomains(5.5%).For 35.7%ofthesubjects,boththeGeneralHealthandthePsychosocialFunctioningdomain contributedtothegfiscores.intotal,28.9%ofthesubjectsexperiencedproblemsinall threedomainsoffrailty. TheVenndiagramrevealedthreegroups:personswithproblemsinonesubscale (N=145),thosewithproblemsintwosubscales(N=239),andthosewithproblemsinall three subscales (N = 156). Table 5 shows the characteristics of these subjects. Subjects thathadproblemsinmultiplesubscalesweresignificantlyolder,onaverage(p<0.001), and had attained a significantly lower educational level (p = 0.004) than those with problemsinonlyonesubscale.gender,livingsituation,andfinancialstatusdidnotdiffer betweenanyofthethreegroups(p>0.05). Table5Percentagesoffrailpersons(GFI4)whoexperienceproblemsinone,two,orthreeGFI domains(n=540)*. OneDomain (n=145) TwoDomains (n=239) ThreeDomains (n=156) F(df) or Chi 2 (df) Meanage(y)SD 73.54± ± ± (2) <0.001 Agegroups 65 69y (8) < y y y >84y Gender Male (2) Female Educationallevel Low (4) Middle High Livingsituation Livingtogether (2) Singleliving Financialstatus Nofinancialproblems (2) Financialproblems GFI=GroningenFrailtyIndicator. *Valuesarepercentagesunlessindicatedotherwise. OnewayANOVAtestresults. Chi 2 testresults. p<0.05. p 2 31

13 Chapter2 2 Among frail subjects, the Chi 2 test revealed dependency between age and the domains DailyActivities(Chi 2 =45.72;df=4;p<0.001)andHealthProblems(Chi 2 =38.69;df=4;p < 0.001). The data provided no support for an increase of psychosocial problems with increasingage(chi 2 =5.04;df=4;p=0.284).ANOVArevealedinteractionsbetweenage and Health Problems (p < 0.001), and age and Daily Activities (p < 0.001). Age did not interactwithpsychosocialfunctioning(p=0.433). DISCUSSION In this study, we examined the structural validity and criterion validity of the GFI questionnaireinolderadults.inaddition,weevaluatedthecompositionofgfiscoresfor frailolderadults.ourfindingssupportathreedimensionalfactorstructureofthegfi,in termsofthesubscalesdailyactivities(items14),psychosocialfunctioning(items1115), andhealthproblems(items510).thismodelexplains50.6%oftheoverallvariance.the internalconsistency,scalability,andcriterionvalidityofthegfisubscalesdailyactivities (Cronbach s=.81,h s=.84,r=.62)andpsychosocialfunctioning(cronbach s=.80,h s =.54,r=.67)aregood.Consequently,bothsubscalesidentifyproblemsinthese frailty domains in a reliable and valid way. The internal consistency, scalability, and criterion validityofthegfisubscalehealthproblemsislessstrong(cronbach s=.57,h s=.35,r=.48). We surmise that the poor reliability and weak scalability of the Health Problems subscale is due to the heterogeneity of items pertaining physical health problems perceivedbyolderadults.thevenndiagramshowingthedistributionofallsubjectswitha totalgfiscoreof4revealedthat27%ofolderadultshadproblemsinonlyonedomain, 44%hadproblemsintwodomains,and29%hadproblemsinallthreedomains(seeFigure 1). Furthermore, the present data suggest that 90% of the frail older adults experience problemsinthepsychosocialfunctioningdomain. Intheliterature,frailtyishypothesizedtoarisefrommultiplecausesandtoaffect multiple domains of physical and cognitive functioning [9,42,43]. In different models of frailty, like the Functional Domains model (the accumulation of deficits), the Burden model (the index of health burden) and the Biologic Syndrome model (frailty as a biologicalsyndrome)multidimensionalscreeninginstrumentsareconsideredtobemost appropriate in screening frailty [44]. Although the conceptualization of the multiple domainsoffrailtyisgenerallyused,thereisnoagreementabouttheincludeddimensions infrailtyinstruments[11,15,45]. Intheassessmentoffrailty,screeninginstrumentsaremostlyemployedinaone dimensionalway.originally,thegfiappliedacutoffpointofasumscoreof4pointsor higher,regardlessofthenumberofdomainsinwhichanolderadultfacedproblems.in addition,otherscreeninginstrumentsthatdistinguishdifferentdomains,likethetilburg 32

14 PsychometricpropertiesoftheGroningenFrailtyIndicator FrailtyIndicatorandtheEdmuntonFrailScale,alsousetotalsumscorestoidentifyfrail olderadults[11,46]. Wesuggesttheresultsofourstudymayimprovetheadequacyofscreeningon frailtyandwillofferspecificindicationsforinterveningintheearlyonsetoffrailty.inthis study,threeseparatedimensionsofthegfiwereestablished.theseresultslendsupport totheuseofthegfiscreeninginstrumentasamultidimensionaltoolfortheanalysisof frailty. When we compare our multidimensional analysis with the originally used one dimensionalapproach,asweshowedinthevenndiagram,wenowgetaclearerpictureof theunderlyingproblemsinthefrailtysumscores.therefore,wequestiontheuseofan overallcutoffpointtoidentifyfrailolderadults.itisclinicallyrelevanttousethegfiasa multidimensional scale consisting of three subscales in order to direct the most appropriatecareandtoprovidefocusedsupporttoolderadultsfacingproblemsinthe differentdimensionsoffrailty.besidesprovidingsupportfortheuseofthegfiscreening instrumentinamultidimensionalway,thepresentstudypromptsafundamentalquestion aboutusinganoverallscorewithoutdelineatingspecificfrailtyproblems.thequestionis: Which combinations of preconditions are in fact essential for a valid assessment of frailty? The lack of a conceptual model in which frailty is specified results in overestimation and inconsistent identification of frailty in older adults. We propose exploringthepossibilityofusingaconditionalcutoffscore,onebasedonboththesum score and the subscale scores. We believe this is necessary for establishing a more convergentdiagnosis. WesuggestemployingamultidimensionalassessmentoffrailtywiththeGFI,one that uses a conditional cutoff point to establish a more convergent diagnosis of frailty. Because frailty is characterized by a decline in reserve capacity in different domains of functioning,wemayconsiderapersontobefrailifheorsheobtainsagfisumscoreofat least4pointsandreportsproblemsinatleasttwodomainsoffrailty. Anumberofrelevantmethodologicalissuesshouldbeconsideredininterpreting theresultsofthisstudy.first,thedesignwascrosssectional.thus,wedidnotevaluate screening results of the GFI over time. Since frailty is a dynamic process that may be reversible,itisrelevanttoestablishthesensitivityofthegfiasascreeninginstrument [47,48]. So far, the GFI is not been used as an evaluative measurement instrument. LongitudinalstudiesshouldclarifythepotentialoftheGFIasanevaluativemeasurement instrumenttoassessthechangesinfrailtystatusovertime. Second, item 5 of the GFI ( How do you rate your physical fitness? ) did not discriminate well among the factors. This finding may be explained by the fact that physical fitness is a multidimensional construct including multiple subcomponents. Furthermore,item5isaselfreportedmeasureofphysicalfitness.Itisknownthatlevels ofselfreportedfunctioningmaybeinfluencedbyaffectivefunctioningofanolderadult [49].Therefore,thecontentofitem5seemstobecoveredbestbythesubscaleHealth 2 33

15 Chapter2 2 Problems, and reliability analysis supports its assignment (higher Cronbach s) to this subscale. Third,anumberofrelevantpersonalcharacteristicswerenottakenintoaccount intheanalysesofourpsychometricstudy.sinceourdataoriginatedfromepidemiological datacollectedbylocalhealthauthorities,itcontainedalimitednumberofbiographicand behavioral data. Therefore, in this study, we could not assess the impact of chronic diseases that may have been present, daily physical activity, physical fitness, and pharmaceutical consumption. It is likely relevant to control for these characteristics to gainmoreinsightintoapplyingthegfi. CONCLUSIONS TheuseofGFIsubscalescoresisdirectlyrelevanttothecareofolderadults.Inourstudy, weidentifiedthreegfisubscalesforassessingfrailtymorespecifically.thesegfisubscale scores produce a richer assessment of frailty than with the overall sum GFI score, and likelytheirusewillcontributetomoredirectedandcustomizedcareforolderadults. 34

16 PsychometricpropertiesoftheGroningenFrailtyIndicator REFERENCES 1. FriedLP,TangenCM,WalstonJ,NewmanAB,HirschC,GottdienerJ,etal.Frailtyinolderadults:Evidencefor aphenotype.jgerontolabiolscimedsci.2001;56: FriedLP,FerrucciL,DarerJ,WilliamsonJD,AndersonG.Untanglingtheconceptsofdisability,frailty,and comorbidity:implicationsforimprovedtargetingandcare.jgerontolabiolscimedsci.2004;59: AhmedN,MandelR,FainMJ.Frailty:anemerginggeriatricsyndrome.AmJMed.2007;120: EtmanA,BurdorfA,VanderCammenTJM,MackenbachJP,VanLentheFJ.Sociodemographicdeterminants of worsening in frailty among communitydwelling older people in 11 European countries. J Epidemiol CommunityHealth.2012;66: PetersonMJ,GiulianiC,MoreyMC,PieperCF,EvensonKR,MercerV,etal.Physicalactivityasapreventative factorforfrailty:thehealth,aging,andbodycompositionstudy.jgerontolabiolscimedsci.2009;64: Chin A Paw M, van Uffelen JG, Riphagen I, van Mechelen W. The functional effects of physical exercise traininginfrailolderpeople:asystematicreview.sportsmed.2008;38: Theou O, Stathokostas L, Roland KP, Jakobi JM, Patterson C, Vandervoort AA, et al. The effectiveness of exerciseinterventionsforthemanagementoffrailty:asystematicreview.jagingres.2011;2011: Eklund K, Wilhelmson K. Outcomes of coordinated and integrated interventions targeting frail elderly people:asystematicreviewofrandomisedcontrolledtrials.healthsoccarecommunity.2009;17: De Vries N, Staal J, van Ravensberg C, Hobbelen J, Olde Rikkert M, Nijhuisvan der Sanden M. Outcome instrumentstomeasurefrailty:asystematicreview.ageingresrev.2011;10: Carrière I, Colvez A, Favier F, Jeandel C, Blain H. Hierarchical components of physical frailty predicted incidenceofdependencyinacohortofelderlywomen.jclinepidemiol.2005;58: GobbensRJJ,vanAssenMALM,LuijkxKG,WijnenSponseleeMT,ScholsJMGA.TheTilburgFrailtyIndicator: psychometricproperties.jammeddirassoc.2010;11: Guilley E, Ghisletta P, Armi F, Berchtold A, d'epinay CL, Michel JP, et al. Dynamics of frailty and ADL dependenceinafiveyearlongitudinalstudyofoctogenarians.resaging.2008;30: JonesDM,SongX,RockwoodK.Operationalizingafrailtyindexfromastandardizedcomprehensivegeriatric assessment.jamgeriatrsoc.2004;52: Kiely DK, Cupples LA, Lipsitz LA. Validation and comparison of two frailty indexes: The MOBILIZE Boston Study.JAmGeriatrSoc.2009;57: Mitnitski AB, Mogilner AJ, Rockwood K. Accumulation of deficits as a proxy measure of aging. ScientificWorldJournal.2001;1: PutsMTE,LipsP,DeegDJH.Sexdifferencesintheriskoffrailtyformortalityindependentofdisabilityand chronicdiseases.jamgeriatrsoc.2004;53: RavagliaG,FortiP,LucicesareA,PisacaneN,RiettiE,PattersonC.Developmentofaneasyprognosticscore forfrailtyoutcomesintheaged.ageageing.2008;37: RolfsonDB,MajumdarSR,TsuyukiRT,TahirA,RockwoodK.ValidityandreliabilityoftheEdmontonFrail Scale.AgeAgeing.2006;35: RothmanMD,LeoSummersL,GillTM.Prognosticsignificanceofpotentialfrailtycriteria.JAmGeriatrSoc. 2008;56: SalibaD,ElliottM,RubensteinLZ,SolomonDH,YoungRT,KambergCJ,etal.TheVulnerableEldersSurvey:a toolforidentifyingvulnerableolderpeopleinthecommunity.jamgeriatrsoc.2001;49: ScarcellaP,LiottaG,MarazziM,CarbiniR,PalombiL.Analysisofsurvivalinasampleofelderlypatientsfrom Ragusa, Italy on the basis of a primary care level multidimensional evaluation. Arch Gerontol Geriatr. 2005;40: SteverinkN,SlaetsJ,SchuurmansH,VanLisM.Measuringfrailty:developingandtestingoftheGroningen FrailtyIndicator(GFI).Gerontologist.2001;41:

17 Chapter StudenskiS,HayesRP,LeibowitzRQ,BodeR,LaveryL,WalstonJ,etal.ClinicalGlobalImpressionofChange inphysicalfrailty:developmentofameasurebasedonclinicaljudgment.jamgeriatrsoc.2004;52: FrieswijkN,BuunkBP,SteverinkN,SlaetsJPJ.Theinterpretationofsocialcomparisonanditsrelationtolife satisfactionamongelderlypeople:doesfrailtymakeadifference?jgerontolbpsychscisocsci.2004;59: Metzelthin S, Daniëls R, Van Rossum E, De Witte L, van den Heuvel W, Kempen G. The psychometric properties of three selfreport screening instruments for identifying frail older people in the community. BMCPublicHealth.2010;10: Peters LL, Boter H, Buskens E, Slaets JPJ. Measurement Properties of the Groningen Frailty Indicator in HomeDwellingandInstitutionalizedElderlyPeople.JAmMedDirAssoc.2012;13: SchuurmansH,SteverinkN,LindenbergS,FrieswijkN,SlaetsJPJ.Oldorfrail:Whattellsusmore?JGerontol ABiolSciMedSci.2004;59: DeJongGierveldJ,vanTilburgT,editors.ManualoftheLonelinessScale.1999.(updatedversion ) ed.amsterdam:vuuniversityamsterdam,departmentofsocialresearchmethodology; Spinhoven P, Ormel J, Sloekers P, Kempen G, Speckens A, Hemert AM. A validation study of the Hospital AnxietyandDepressionScale(HADS)indifferentgroupsofDutchsubjects.PsycholMed.1997;27: VanderZeeK,SandermanR.RAND36.Groningen:NorthernCentreforHealthCareResearch,Universityof Groningen,theNetherlands; The EuroQol Group. EuroQola new facility for the measurement of healthrelated quality of life. Health Policy.1990;16: de Jong Gierveld J, Van Tilburg T. A shortened scale for overall, emotional and social loneliness. Tijdschr GerontolGeriatr.2008;39: MoorerP, Suurmeijer TPBM, Foets M, Molenaar I. Psychometric properties of the RAND36 among three chronicdisease(multiplesclerosis,rheumaticdiseasesandcopd)inthenetherlands.qualliferes.2001;10: Mokkink LB, Terwee CB, Patrick DL, Alonso J, Stratford PW, Knol DL, et al. The COSMIN study reached internationalconsensusontaxonomy,terminology,anddefinitionsofmeasurementpropertiesforhealth relatedpatientreportedoutcomes.jclinepidemiol.2010;63: NunnallyJ.Psychometricmethods.NewYork,NY:McGrawHill; GeorgeD,MalleryM.UsingSPSSforWindowsstepbystep:asimpleguideandreference.Boston,MA:Allyn &Bacon; MokkenRJ,LewisC.Anonparametricapproachtotheanalysisofdichotomousitemresponses.ApplPsychol Meas.1982;6: HemkerBT,SijtsmaK,MolenaarIW.SelectionofUnidimensionalScalesFromaMultidimensionalItemBank inthepolytomousmokkenirtmodel.applpsycholmeas.1995;19: MokkenRJ.Nonparametricmodelsfordichotomousresponses.NewYork:Springer;1997: CohenJ.Statisticalpoweranalysisforthebehavioralsciences.2nded.ed.Hillsdale,NJ:LawrenceErlbaum Associates; BuurenS,GroothuisOudshoornK.MICE:multivariateimputationbychainedequationsinR.JStatSoftw. 2011;45: PialouxT,GoyardJ,LesourdB.Screeningtoolsforfrailtyinprimaryhealthcare:Asystematicreview.Geriatr GerontolInt.2012;12: MarkleReidM,BrowneG.Conceptualizationsoffrailtyinrelationtoolderadults.JAdvNurs.2003;44: CigolleCT,OfstedalMB,TianZ,BlaumCS.Comparingmodelsoffrailty:theHealthandRetirementStudy.J AmGeriatrSoc.2009;57: WalstonJ,HadleyEC,FerrucciL,GuralnikJM,NewmanAB,StudenskiSA,etal.Researchagendaforfrailtyin older adults: toward a better understanding of physiology and etiology: summary from the American 36

18 PsychometricpropertiesoftheGroningenFrailtyIndicator GeriatricsSociety/NationalInstituteonAgingResearchConferenceonFrailtyinOlderAdults.JAmGeriatr Soc.2006;54: Hábert R, Bravo G, KornerBitensky N, Voyer L. Predictive validity of a postal questionnaire for screening communitydwellingelderlyindividualsatriskoffunctionaldecline.ageageing.1996;25: WilsonJF.Frailtyanditsdangerouseffectsmightbepreventable.AnnInternMed.2004;141: Puts MTE, Shekary N, Widdershoven G, Heldens J, Lips P, Deeg D. Frailty: biological risk factors, negative consequencesandqualityoflife,vuuniversityamsterdam; KempenGIJM,VanHeuvelenMJG,VandenBrinkRHS,KooijmanAC,KleinM,HouxPJ,etal.Factorsaffecting Contrasting Results between Selfreported and Performancebased Levels of Physical Limitations. Age Ageing.1996;25:

19 Chapter2 APPENDIX1 TheGroningenFrailtyIndicator(GFI) 2 DailyActivities Areyouabletocarryoutthesetasksindependentlywithoutanyhelp?Theuseofresourcessuchas walkingstick,walkingframe,wheelchair,isconsideredindependent. 1. Shopping 2. Walkingaroundoutside(aroundthehouseortotheneighbors) 3. Dressingandundressing 4. Goingtothetoilet HealthProblems 5. Howdoyourateyourphysicalfitness?(scale0to10) 6. Doyouexperienceproblemsindailylifeduetopoorvision? 7. Doyouexperienceproblemsindailylifeduetobeinghardofhearing? 8. Duringthelast6months,didyoulostalotofweightunwillingly?(3kgin1monthor6kgin2 months) 9. Doyoutake4ormoredifferenttypesofmedicine? 10. Doyouhaveanycomplaintsaboutyourmemory? PsychosocialFunctioning 11. Doyousometimesexperienceanemptinessaroundyou? 12. Doyousometimesmisspeoplearoundyou? 13. Doyousometimesfeelabandoned? 14. Didyoufeltdownheartedorsadrecently? 15. Didyoufeltnervousoranxiousrecently? Scoring: Questions1 4:Yes=0;No=1 Question5:0 6=1;7 10=0 Questions6 9:Yes=1;No=0 Question10:Yes=1;Sometimes=0;No=0 Question11 15:Yes=1;Sometimes=1;No=0 38

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