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

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

3. 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

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

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

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

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

8. 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

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

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

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

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

13. 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:

14. 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

15. 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:

16. 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:
Schiemanck, S. K. et al. Stroke 2006;37:
Copyright ©2006 American Heart Association

17. 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:

18. 78
Internal validity
Statistical validity
13 (8)
external validity

19. 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

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

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

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

23. Mean recovery pattern of Barthel Index
prediction
outcome

24. 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

25. 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 = (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)

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

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

28. 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:

29. 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:
-1.4
feeding
easy
Van Hartingsveld et al, Stroke. 2006;37:
Copyright ©2006 American Heart Association

30. 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.

31. Mijn dank voor uw aandacht!

32. 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.

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

34. 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?

35. Rehabilitation centre
Hospital
Rehabilitation centre
Home/ Nursing house
% herstel

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

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

38. 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

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

40. CONSENSUS Clinimetrics objectivity communication reliability validity
responsiveness
hierarchy

41. 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).

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

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

44. Samenvattingskaart

45. 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: