Klinimetrie bij het stellen van de functionele prognose na een CVA: hulp of last? Dr. G. Kwakkel

Identify patient’s problem Define a meaningful question Determine the prognosis Select most appropriate therapy Evaluate efficacy

Doel van het (klinisch) meten om te onderscheiden (diagnostiseren en/of klassificeren) om te voorspellen om (verandering) te evalueren Kirshner & Guyatt, J. Chron. Dis 1985; 38: 27

clinical decision making outcome of ADL ? home at 6 months ? clinical decision making needs further help ? patients future

hypothetico-deductive reasoning? pattern recognition hypothetico-deductive reasoning? problem solving ? intuition ? outcome of ADL ? home at 6 months? needs further help? patients future

(1) Prediction of what? Outcome of what? determinant

Interaction of Concepts ICF 2001 Health Condition (disorder/disease) Body function&structure (Impairment) Activities (Limitation) Participation (Restriction) ? ? Environmental Factors Personal Factors

Which construct (at level of activity) do we exactly like to predict? Neuro-psychology Clinical neurology Functional outcome (e.g., dexterity, walking ability, (I)ADL-independency determinant Neuro-physiology Neuroradiology Demographic factors

Functional Ambulation Categories Barthel Index ARAT Arm-handvaardigheid Basic ADL ? Loopvaardigheid Functional Ambulation Categories

Construct validity of BI (N=89) Correlation coefficient (rs) weeks

Construct validity of BI (N=89) Correlation coefficient (rs) weeks

(2) Which determinants are valid? Neuro-psychology Clinical neurology Functional outcome of basic ADLs determinant Neuro-physiology Neuroradiology Demographic factors

I . Key methodological criteria for prognostic research internal validity reliable and valid measurements inception cohort appropriate end-points of observation control of patient drop-out statistical validity control for statistical significance adequate estimation of sample-size control for multicollinearity Kwakkel et al, Age & Ageing 1996;25:479-489

r y.x1 r x1.x2 r y.x2 Factor x1 Outcome Y Factor x2 (explained variance) r x1.x2 r y.x2 Factor x2

Predictive value of volume of stroke according to MRI scan for outcome of ADL-independency at 6 months post stroke Schiemanck et al, Stroke. 2006;37:1050-1054

Model 1 (AUC=0.83) = age and IBI Receiver operating curves of model 1 (clinical) and model 2 (clinical imaging) (N=75) Model 1 (AUC=0.83) = age and IBI Model 2 (AUC =0.87) = Model 1 + volume MRI Schiemanck et al, Stroke. 2006;37:1050-1054. Schiemanck, S. K. et al. Stroke 2006;37:1050-1054 Copyright ©2006 American Heart Association

II. Key methodological criteria for prognostic research external validity specification of inclusion and exclusion criteria description of additional treatment effects during period of observation cross-validation of the prediction model Kwakkel et al, Age & Ageing 1996;25:479-489

78 Internal validity Statistical validity 13 (8) external validity

Valid predictors for ADL (and walking ability) admission ADL (i.e., assessment specific) urinary (in)continence age* previous stroke (and other disabling co-morbidity) consciousness at onset severity of paresis sitting balance orientation in time and place level of social support inattention depression

Possible negative predictors for ADL homonymous hemianopia conjugate deviation of the eyes fatigue dyspraxia dysphasia ??

Variables not related to outcome of ADL gender ethnic origin side of stroke Kwakkel et al., Age & Ageing, 1996: 25:479-489

Individual recovery patterns of Barthel Index (n=13) BI-score weeks weeks

Mean recovery pattern of Barthel Index prediction outcome

Regression model statistics for outcome of BI Intercept Initial BI Sitting balance Soc. Support age * Model Nh Pooled Eigenvalue 4.291 0.363 0.226 0.110 0.023 0.106 0.120 CI 1.0 3.44 4.36 6.24 13.66 5.71 5.34 R-square 0.51 0.61 0.64 0.67 0.52 0.57

BI = 42.29 + (0.51 * IBI) + (20.93 * SB) + (10.35 * SS) Final regression model for outcome of Barthel Index at 6 months post stroke BI = 42.29 + (0.51 * IBI) + (20.93 * SB) + (10.35 * SS) BI= (Initial) Barthel Index (ranging from 0-100) SB=initial sitting balance (yes/no on the TCT) SS= Social Support (yes/no: having a partner able to support)

Increment in explained variance for outcome of BI score (N=102) model retesting

Effects of initial BI on outcome at 6 months post stroke (N=89) Adjusted R2=0.50 (Initial BI)

Coefficient of Scalability: 0.72 (week 26) < CS <0.85 (week3) Barthel Index bowel grooming bladder feeding transfer toilet use mobility bathing dressing stairs Rest. Neurology & Neuroscience 2004;22: 281-299

Logit item step difficulties (I) of the Rasch homogeneous 8-item Barthel scale (N=559). Logit item step difficulties ({beta}I) of the Rasch homogeneous 8-item Barthel scale difficult 1.4 1.2 stairs 1.0 0.8 bathing 0.6 dress step 2 0.4 mobility step 2 0.2 toilet -0.2 dress step 1 -0.4 groom -0.6 -0.8 -1.0 transfer step 1 -1.2 van Hartingsveld, F. et al. Stroke 2006;37:162-166 -1.4 feeding easy Van Hartingsveld et al, Stroke. 2006;37:162-166. Copyright ©2006 American Heart Association

Take home message: Barthel Index gemeten in de eerste 2 weken na een CVA is een robuuste determinant voor het uiteindelijk te verwachten herstel op de BI na 6 maanden. Een klinimetrische testuitslag krijgt pas een prognostische (meer)waarde wanneer men deze relateert aan het moment waarop het CVA heeft plaatsgevonden. Functionele prognostiek is pas mogelijk wanneer men eveneens kennis heeft over de psychometrische eigenschappen van gebruikte meetinstrumenten.

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Advantage of clinimetrics (2): Clinical assessments increase the transparency in making client-related decisions within a team of professionals working together as a stroke team.

Increment in explained variance for outcome of BI, FAC and ARA score (N=102)

Steps to follow for getting relation coordination consensus in clinimetrics: What do we measure systematically? How do we measure systematically? Who is measuring what? When do we measure the stroke patient?

Rehabilitation centre Hospital Rehabilitation centre Home/ Nursing house % herstel

Rehabilitation centre Hospital Rehabilitation centre Home/ Nursing house % herstel ?

Rehabilitation centre ‘learning from making functional prognosis’ Hospital Rehabilitation centre Home/ Nursing house ? % herstel ‘learning from making functional prognosis’

Clinimetrics (ICF 2001) activities participation pathology impairment disability handicap MI-score FM-motor score Ashworth Scale Thumb-Finding Test Letter cancellation task, line-bisection task MMSE Scan. Stroke Scale Trunk Control Test Berg-Balance Scale Timed-Balance test Timed-Get-up & Go-Test FAC, 10-meter walking test ARA, Frenchay Arm Barthel Index FAI, EADL OCSP Stroke type Number of strokes Epilepsy HSP, GHS SHS SIP-68 NHP-part 1 Post-stroke Depression Carer Strain Index Satisfaction Questionnaires

Construct validiteit van de BI (N=89) Pearson correlation coefficients with Barthel Index weeks

CONSENSUS Clinimetrics objectivity communication reliability validity responsiveness hierarchy

Advantage of clinimetrics: From perspective of a health care professional: Assessment contribute to set realistic and therapeutically attainable treatment goals (i.e., improves objectivity). From perspective of a (stroke) team: Clinical assessments increase the transparency in making client-related decisions within a team of professionals working together as a stroke team (i.e., improves communication).

Stroke Guidelines Multidisciplinary guidelines for stroke financed by the Dutch Heart Foundation

http://www.kngf.nl/ Praktijkrichtlijn Samenvattingskaart Deskundigheidsbevorderingspakket Verantwoording en toelichting

Samenvattingskaart

Conclusion Not only differences in heterogeneity in stroke patients are responsible for lack of accuracy in predicting functional outcome, but also the methodological shortcomings in published prognostic research Kwakkel et al., Age & Ageing, 1996: 25:479-489