Neurorehabilitation and Neural
Repair
http://nnr.sagepub.com/
Assessing the Streamlined Wolf Motor Function Test as an Outcome Measure for Stroke Rehabilitation
Ching-yi Wu, Tiffany Fu, Keh-chung Lin, Chi-tzu Feng, Kuang-ping Hsieh, Hung-wen Yu, Chia-huang Lin, Ching-ju Hsieh
and Hisaaki Ota
Neurorehabil Neural Repair published online 14 October 2010
DOI: 10.1177/1545968310381249
The online version of this article can be found at:
http://nnr.sagepub.com/content/early/2010/10/14/1545968310381249
Published by:
http://www.sagepublications.com
On behalf of:
American Society of Neurorehabilitation
Additional services and information for Neurorehabilitation and Neural Repair can be found at:
Email Alerts: http://nnr.sagepub.com/cgi/alerts
Subscriptions: http://nnr.sagepub.com/subscriptions
Reprints: http://www.sagepub.com/journalsReprints.nav
Permissions: http://www.sagepub.com/journalsPermissions.nav
Downloaded from nnr.sagepub.com at UNIV OF DELAWARE LIB on November 10, 2010
Assessing the Streamlined Wolf Motor
Function Test as an Outcome Measure
for Stroke Rehabilitation
Neurorehabilitation and
Neural Repair
XX(X) 1­–6
© The Author(s) 2010
Reprints and permission: http://www.
sagepub.com/journalsPermissions.nav
DOI: 10.1177/1545968310381249
http://nnr.sagepub.com
Ching-yi Wu, ScD1,Tiffany Fu, PhD2, Keh-chung Lin, ScD2,3,
Chi-tzu Feng4, Kuang-ping Hsieh5, Hung-wen Yu6,
Chia-huang Lin7, Ching-ju Hsieh, MD8, and Hisaaki Ota, PhD9
Abstract
Objective. This study investigates the clinimetric properties of the streamlined Wolf Motor Function Test (WMFT), a 6-item
version of the performance time scale of the WMFT. Methods. The streamlined WMFT, along with 2 criterion measures, the
Fugl-Meyer Assessment (FMA) and the Stroke Impact Scale (SIS), were administered to 64 stroke patients before and after
a 3-week intervention. Responsiveness was examined using the Wilcoxon signed rank test and standardized response mean
(SRM). Criterion-related validity was investigated using the Spearman correlation coefficient (ρ). Results. The mean score on
the baseline FMA upper extremity of the patients was 44.84 (standard deviation = 12.77). The streamlined WMFT and the
original performance time scale showed comparable responsiveness (SRM = 0.29 and 0.37, respectively). The concurrent
validity of the streamlined WMFT was good (ρ = 0.57-0.69). For predictive validity, the streamlined WMFT showed slightly
better association with the criterion measures (ρ = 0.60-0.68) than did the original scale (ρ = 0.56-0.64). Conclusions.
Compared with the original scale, the streamlined WMFT showed improved clinical utility.
Keywords
cerebrovascular accident, rehabilitation, outcome measures, clinimetrics, Wolf Motor Function Test, streamlining
Introduction
The 21-item Wolf Motor Function Test (WMFT) was
originally developed to assess the effects of constraintinduced movement therapy on the return of upper
extremity (UE) movement ability in stroke survivors.1 It
was subsequently modified and contains 17 tasks, including
2 strength-based tasks and 15 function-based tasks, divided
into 2 scales: performance time and functional ability.2
The reliability and validity of the WMFT have been well
established in previous studies. The WMFT had good
test-retest reliability2,3 and criterion validity3,4 for performance time and functional ability. In addition, interrater
reliability of the WMFT was high (range, 0.97-0.99).5
This test has been widely used as an outcome measure in
stroke motor rehabilitation trials.6-10
Owing to lengthy administration times, the WMFT was
further shortened to 6 tasks in a recent study.11 Although the
6 tasks of the streamlined WMFT had a significant relationship with overall improvement in the Extremity Constraint
Induced Therapy Evaluation (EXCITE) trial,11 no study to
date has reported the sensitivity of change of this shortened
version. To be of practical use in rehabilitation trials, the
short form of an outcome measure should not only show
reliability and validity but also be sensitive in measuring
change within persons over time.12 That is, the demonstration
of sound clinimetric properties of an outcome measure is a
priority before its application in clinical trials or in the evaluation of the effects of rehabilitation therapies.13,14
Because the streamlined WMFT has not been sufficiently validated, the responsiveness and criterion validity
of the short form of the WMFT remain unknown. To address
the gap, we evaluated the clinimetric properties of the
streamlined WMFT in a stroke cohort other than the sample
1
Chang Gung University, Taoyuan, Taiwan
National Taiwan University, Taipei, Taiwan
3
National Taiwan University Hospital, Taipei, Taiwan
4
Buddhist Tzu Chi General Hospital, Taipei Branch, Taipei, Taiwan
5
Cheng Hsin General Hospital, Taipei, Taiwan
6
Mackay Memorial Hospital, Taipei, Taiwan
7
Taipei Medical University–Shuang Ho Hospital, Taipei, Taiwan
8
Taipei City Hospital-Heping Branch, Taipei, Taiwan
9
Sapporo Medical University Hospital, Sapporo, Japan
2
Corresponding Author:
Keh-chung Lin, School of Occupational Therapy, College of Medicine,
National Taiwan University and Division of Occupational Therapy,
Department of Physical Medicine and Rehabilitation, National Taiwan
University Hospital, 17, F4, Xu Zhou Road, Taipei, Taiwan
Email: kehchunglin@ntu.edu.tw
Downloaded from nnr.sagepub.com at UNIV OF DELAWARE LIB on November 10, 2010
2
Neurorehabilitation and Neural Repair XX(X)
studied in the EXCITE trial. Responsiveness indicates an
instrument’s ability to detect the smallest change in score.15
Furthermore, responsiveness is neither a constant statistic
nor a context-free attribute.16 In other words, responsiveness of an instrument should be described in relation to a
particular group of people under certain conditions. Lin et al3
studied the responsiveness of the WMFT during the recovery
course of the first 6 months after stroke, but no rehabilitation therapy was specified for the change in WMFT. This
study evaluated the responsiveness of the streamlined
WMFT in patients with subacute stroke, defined as 3 to 9
months poststroke in the Bogard et al study,11 who had
undergone rehabilitation therapies.
As suggested by Bogard et al,11 this study also examined
the criterion validity of the streamlined WMFT. Criterion
validity includes concurrent validity and predictive validity,
which considers the degree of consistency of an instrument
with the criterion measures and the ability of an instrument
to predict future events.17 The examination of the concurrent validity of the streamlined WMFT enables researchers
to determine if this streamlined version measures the same
construct as is assessed by the 17-item WMFT. The streamlined WMFT may be taken as an important tool for guiding
clinical decision making for rehabilitation goal planning if
it shows a level of predictive validity similar to that of the
17-item WMFT.
The purpose of the present study was therefore to examine the clinimetric domains of the streamlined WMFT,
including the responsiveness and validity (concurrent and
predictive validity) in a cohort of subacute stroke patients.
Because Bogard et al11 suggested that the tasks selected
for streamlined WMFT depend on the time poststroke
(subacute vs chronic), we used the streamlined WMFT with
6 tasks appropriate for subacute patients.
Methods
Participants
The study participants were obtained primarily from those
enrolled in one of our previous studies.18 An additional 10
participants were recruited from the departments of rehabilitation at 3 medical centers. The inclusion criteria were:
(1) a first-ever stroke with onset of more than 3 months and
less than 10 months; (2) demonstration of Brunnstrom
stage III or higher for the proximal part of the affected
upper limb19; (3) no serious cognitive deficits, as defined
by a score of more than 24 on the Mini Mental-State
Exam20; and (4) no excessive spasticity at any joint of the
upper limb, as defined by a score of 2 or less on the Modified Ashworth Scale.21 To eliminate the potential effects of
comorbid medical conditions on the study results, we
excluded participants with physician-determined major
medical problems, such as severe aphasia or a vision
problem or those in poor physical condition. Patients were
able to understand the meaning of the study and provided
written informed consent approved by the ethics committees of the participating sites.
Intervention and Procedure
Patients were randomized to receive 1 of the following
2-hour therapies every weekday for 3 weeks: distributed
constraint-induced therapy (CIT),22 bilateral arm training
(BAT),23 or conventional rehabilitation.24 The distributed
CIT group focused on restriction of movement of the unaffected limb and intensive training of the affected limb. The
BAT group concentrated on moving the affected and the
unaffected upper limbs simultaneously with functional symmetric tasks. The conventional rehabilitation group focused
on neurodevelopment techniques with an emphasis on functional task practice, when possible. The interventions were
provided at the participating hospitals under the supervision
of 3 certificated occupational therapists. The patients were
evaluated at baseline and immediately after 3 weeks of therapy by 3 raters blinded to the participant group. The raters
were trained to administer the WMFT.
Measures
The 15 function-based tasks of the WMFT are divided into
the performance time scale and the functional ability
scale.25 Because the streamlined WMFT includes 6 timed
tasks,11 only the performance time scale of the WMFT was
used to assess UE movement ability in this study. The 6
tasks included hand to table, hand to box, reach and
retrieve, lift can, lift pencil, and fold towel. The UE subscale of the Fugl-Meyer Assessment (FMA)26 is a valid
and reliable index measuring motor impairment in stroke
patients.27,28 The Stroke Impact Scale version 3 (SIS 3.0)29
consists of 59 items measuring the 8 domains of strength,
hand function, activities of daily living (ADL)/instrumental
ADL (IADL), mobility, communication, emotion, memory/
thinking, and participation, with established reliability
and validity.30-32
Data Analysis
Responsiveness. The responsiveness of the streamlined WMFT
compared with the WMFT was examined according to
changes from pretreatment to posttreatment. Because of
the skewed distribution of the original data, a logarithmic
transformation was used.33 The Wilcoxon signed rank
test was performed to determine if statistically significant
differences in mean change score (MCS) occurred. The
standardized response mean (SRM)34 was estimated as the
Downloaded from nnr.sagepub.com at UNIV OF DELAWARE LIB on November 10, 2010
3
Wu et al
ratio of the MCS to the standard deviation of the MCS.35
To classify the values of SRM as nonresponsive (<0.2),
small (0.2-0.5), medium (0.5-0.8), and large (>0.8) using
the Cohen criteria for effect size d, SRM was adjusted
using the formula: Effect size d = SRM × √2.36 The bootstrap
resampling procedure was used to estimate the 95% confidence intervals (CIs) for the SRMs and to examine the
level of significance of the SRM differences between the
streamlined WMFT and the WMFT.37 A significant SRM
difference between the 2 tests was determined if the value
0 was not included between the 25th and the 975th observations taken from the 1000 paired bootstrap samples of
the 2 measures.38
Validity. Concurrent validity was examined by correlating
the average score of the timed tasks of the WMFT with the
scores of the FMA and those of the SIS hand function subscale by using Spearman rank correlation coefficients (ρ) at
baseline and at follow-up. The FMA and SIS hand function
were chosen because they and the WMFT measure similar
constructs. Predictive validity between the WMFT scores at
baseline and the scores on the criterion measures at followup was assessed by examining the association with Spearman
ρ correlation coefficients. The strengths of the relationship
were classified as excellent (ρ > 0.75), good (ρ = 0.5-0.75),
fair (ρ = 0.25-0.5), and low (ρ ≤ 0.25).15
Results
The demographic and clinical characteristics of the participants (50 men, 14 women; mean age, 53.01 years) are
summarized in Table 1. The mean scores of the performance
time scale at baseline were 7.45 s for the streamlined WMFT
and 9.44 s for the WMFT. Results of the clinimetric study of
the streamlined WMFT and the WMFT are presented in
Tables 2, 3, and 4 to facilitate the comparison and discussion
of the measurement properties between the 2 scales.
Responsiveness
The responsiveness indices of the streamlined WMFT
and WMFT are listed in Table 2. The pretreatment to posttreatment changes assessed by both tests were significant
(P < .01). The responsiveness of both tests was small to
moderate (adjusted SRM: effect size d = 0.41-0.52), and the
responsiveness of the WMFT and the streamlined WMFT
was not significantly different (SRM difference = 0.08;
95% CI = −0.17 to 0.27).
Concurrent Validity
Table 3 shows that the interrelationships of data obtained
with the streamlined WMFT, WMFT, FMA, and SIS hand
function were ρ ≥ 0.51 (P < .01). These results indicated
Table 1. Baseline Characteristics of the Participants (N = 64)
Characteristic
Value
Gender, n
Male
Female
Age, mean (SD) years
Side of stroke, n
Right
Left
Months after stroke, mean (SD)
Brunnstrom stage of proximal part of UE,
median (range)
Fugl-Meyer baseline UE scores, mean (SD)
Mini Mental-State Exam scores, mean (SD)
S-WMFT, mean (SD)
WMFT, mean (SD)
50
14
53.01 (12.75)
33
31
7.88 (1.69)
4 (3-6)
44.84 (12.77)
7.72 (2.31)
7.45 (10.40)
9.44 (10.19)
Abbreviations: SD, standard deviation; UE, upper extremity;
S-WMFT, streamlined Wolf Motor Function Test; WMFT, Wolf Motor
Function Test.
Table 2. Responsiveness of the S-WMFT and WMFT
Test
Wilcoxon Z
Log S-WMFT time
Log WMFT time
a
2.82
4.42a
SRM
Effect Size d
0.29
0.37
0.41
0.52
Abbreviations: S-WMFT, streamlined Wolf Motor Function Test; WMFT,
Wolf Motor Function Test; SRM, standardized response mean; S-WMFT
time, performance time of the streamlined Wolf Motor Function Test;
WMFT time, performance time of the Wolf Motor Function Test.
a
P < .01.
Table 3. Concurrent Validity of the S-WMFT and WMFT
Baseline Scores
Posttreatment Scores
Criterion
Measure
S-WMFT
WMFT
S-WMFT
WMFT
FMA
SIS hand
0.69a
0.59a
0.64a
0.51a
0.58a
0.57a
0.64a
0.54a
Abbreviations: S-WMFT, streamlined Wolf Motor Function Test; WMFT,
Wolf Motor Function Test; FMA, Fugl-Meyer Assessment; SIS hand, SIS
hand function subscale.
a
P < .01.
that the streamlined WMFT demonstrated good concurrent
validity, as was shown by the WMFT.
Predictive Validity
The scores of the streamlined WMFT and WMFT significantly correlated with the scores of FMA and SIS hand
function (ρ ≥ 0.56, P < .01; Table 4). The predictive validity
of data obtained with the streamlined WMFT was similar to
that of data obtained with the original version.
Downloaded from nnr.sagepub.com at UNIV OF DELAWARE LIB on November 10, 2010
4
Neurorehabilitation and Neural Repair XX(X)
Table 4. Predictive Validity of the S-WMFT and WMFT
Scores at Baseline
Criterion Measure
FMA
SIS hand
S-WMFT
a
0.68
0.60a
WMFT
0.64a
0.56a
Abbreviations: S-WMFT, streamlined Wolf Motor Function Test; WMFT,
Wolf Motor Function Test; FMA, Fugl-Meyer Assessment; SIS hand, SIS
hand function subscale.
a
P < .01.
Discussion
The present study is the first to systematically assess the clinimetric properties of the streamlined WMFT in participants
with subacute stroke. This research extended what Bogard
et al11 reported by showing that the sensitivity to change after
rehabilitation therapies for the streamlined WMFT was not
significantly different from that for the original version. Furthermore, the criterion validity of the streamlined WMFT
was essentially identical to that of the original performance
time scale of the WMFT.
Responsiveness is an important quality for any instrument used to evaluate change over time.15 Responsiveness
involves at least 2 aspects: the improvement over time
and the magnitude of the change in scores.39 The time
score of the streamlined WMFT improved after rehabilitation (Wilcoxon Z = 2.82), as did the WMFT (Wilcoxon
Z = 4.42). No significant differences in the magnitude of
change between the 2 tests were found, although the SRM
of the WMFT was slightly larger than that of the streamlined WMFT. These findings indicate that the streamlined
WMFT might be acceptable, instead of the original version, as an outcome measure for detecting changes after
rehabilitation. The slight differences in responsiveness
observed between the 2 tests may be explained by the
number of tasks.40 Although the streamlined WMFT comprises only 6 tasks, the original scale includes 15. Because
the inclusion of a greater number of tasks may reduce error
variance, the sensitivity of the original performance time
scale may be increased.
The findings on responsiveness of WMFT and streamlined WMFT extend the results of the Bogard et al11 study
on the streamlined WMFT and the Lin et al3 study on the
WMFT in rehabilitation therapy and sample characteristics.
Specifically, the participants in the present study received a
3-week therapy of distributed CIT, BAT, or the conventional rehabilitation, whereas those in the EXCITE trial11
attended a 2-week therapy of standard CIT and those in the
Lin et al3 study might not have attended specific intervention programs. The WMFT and streamlined WMFT tasks
that change in response to CIT may also respond to other
types of UE training approaches, such as distributed CIT
and BAT in our present study. In addition, the participants
in this study were different from those in the EXCITE study
by Bogard et al,11 which may increase the applicability and
value of the streamlined WMFT.
The validity of an instrument informs researchers about
whether the tool evaluates what it is intended to measure.15
In the present study, the associations between the streamlined WMFT and the FMA as well as the SIS hand function
subscale (ρ = 0.57-0.69) were similar to those of the original scale (ρ = 0.51-0.64). These findings lent strong support
for the concurrent validity of the streamlined WMFT for
assessing UE movement ability in stroke survivors. For predictive validity, our results showed that the correlations
between the streamlined WMFT and the criterion measures
(ρ = 0.60-0.68) were slightly higher than those of the original scale (ρ = 0.56-0.64), which provides strong evidence to
suggest that the streamlined WMFT score is a good predictor of return of UE function after stroke rehabilitation.
Taken together, the findings of our study confirm the criterion validity of the streamlined WMFT as an outcome
measure for patients with subacute stroke.
The results of the present study need to be considered in
light of some limitations. First, only patients with subacute
stroke were included, and the results may not be generalizable to other patient populations. Future research needs to
address the issue of applicability of the streamlined WMFT
in patients with characteristics different from those enrolled
in this study and those studied by Bogard et al11 in order to
promote the clinical utility of this assessment tool. Second,
because the current findings were derived from a small
sample size, more research with larger sample sizes will be
required to further examine the clinimetric properties of the
streamlined WMFT. Such research may help improve outcome evaluations in stroke patients. Third, because the
scores on the streamlined WMFT were extracted from the
original scale, further study needs to validate the current
clinimetric findings by directly administering the 6-item
version of the WMFT to the participants.
Conclusion
The streamlined WMFT demonstrated good criterion validity
in patients with subacute stroke. Although the streamlined
WMFT was slightly less sensitive than the original performance time scale of the WMFT, no significant difference
in sensitivity between the 2 versions was found. Taken
together, because the values of the responsiveness of the
2 scales are modest, and the streamlined WMFT has similar concurrent validity and slightly better predictive validity
when compared with the original scale, we consider that
this 6-item version of the WMFT showed improved clinical utility.
Downloaded from nnr.sagepub.com at UNIV OF DELAWARE LIB on November 10, 2010
5
Wu et al
Declaration of Conflicting Interests
The author(s) declared the following potential conflicts of interest
with respect to the authorship and/or publication of this article.
Funding
The author(s) received no financial support for the research and/or
authorship of this article.
This project was supported in part by the National Science Council (NSC-97-2314-B-182-004-MY3, NSC-97-2811-B-002-101,
and NSC-98-2811-B-002-073) and the National Health Research
Institutes (NHRI-EX99-9742PI and NHRI-EX99-9920PI) in Taiwan.
References
1. Wolf SL, Lecraw DE, Barton LA, Jann BB. Forced use of
hemiplegic upper extremities to reverse the effect of learned
nonuse among chronic stroke and head-injured patients. Exp
Neurol. 1989;104:125-132.
2. Morris DM, Uswatte G, Crago JE, Cook EW 3rd, Taub E.
The reliability of the Wolf Motor Function Test for assessing
upper extremity function after stroke. Arch Phys Med Rehabil.
2001;82:750-755.
3. Lin JH, Hsu MJ, Sheu CF, et al. Psychometric comparisons of
4 measures for assessing upper-extremity function in people
with stroke. Phys Ther. 2009;89:840-850.
4. Whitall J, Savin DN Jr, Harris-Love M, Waller SM. Psychometric properties of a modified Wolf Motor Function Test for
people with mild and moderate upper-extremity hemiparesis.
Arch Phys Med Rehabil. 2006;87:656-660.
5. Wolf SL, Catlin PA, Ellis M, Archer AL, Morgan B,
Piacentino A. Assessing Wolf Motor Function Test as outcome
measure for research in patients after stroke. Stroke. 2001;
32:1635-1639.
6. Caimmi M, Carda S, Giovanzana C, et al. Using kinematic
analysis to evaluate constraint-induced movement therapy
in chronic stroke patients. Neurorehabil Neural Repair.
2008;22:31-39.
7. Taub E, Miller NE, Novack TA, et al. Technique to improve
chronic motor deficit after stroke. Arch Phys Med Rehabil.
1993;74:347-354.
8. Park SW, Wolf SL, Blanton S, Winstein C, Nichols-Larsen DS.
The EXCITE trial: predicting a clinically meaningful motor
activity log outcome. Neurorehabil Neural Repair. 2008;22:
486-493.
9. Bonifer NM, Anderson KM, Arciniegas DB. Constraintinduced therapy for moderate chronic upper extremity impairment after stroke. Brain Inj. 2005;19:323-330.
10. Rijntjes M, Hobbeling V, Hamzei F, et al. Individual factors
in constraint-induced movement therapy after stroke. Neurorehabil Neural Repair. 2005;19:238-249.
11. Bogard K, Wolf SL, Zhang Q, Thompson P, Morris DM,
Nichols-Larsen D. Can the Wolf Motor Function Test be
streamlined? Neurorehabil Neural Repair. 2009;23:422-428.
12. Kanwal F, Spiegel BM, Hays RD, et al. Prospective validation
of the short form liver disease quality of life instrument. Aliment Pharmacol Ther. 2008;28:1088-1101.
13. Barker AL, Nitz JC, Choy NLL, Haines T. Measuring fall risk
and predicting who will fall: clinimetric properties of four fall
risk assessment tools for residential aged care. J Gerontol.
2009;64A:916-924.
14. Hsieh YW, Wu CY, Lin KC, Chang YF, Chen CL, Liu JS.
Responsiveness and validity of three outcome measures of
motor function after stroke rehabilitation. Stroke. 2009;40:
1386-1391.
15. Portney LG, Watkins MP. Foundations of Clinical Research:
Applications to Practice. 3rd ed. Upper Saddle River, NJ:
Pearson/Prentice Hall; 2009.
16. McMillan CR, Binhammer PA. Which outcome measure is
the best? Evaluating responsiveness of the Disabilities of the
Arm, Shoulder, and Hand Questionnaire, the Michigan Hand
Questionnaire and the Patient-Specific Functional Scale following hand and wrist surgery. Hand (N Y). 2009;4:311-318.
17. Fayers PM, Machin D. Quality of Life—The Assessment,
Analysis and Interpretation of Patient-Reported Outcomes.
New York, NY: John Wiley; 2007.
18. Lin KC, Fu T, Wu CY, et al. Minimal detectable change and
clinically important difference of the Stroke Impact Scale
in stroke patients. Neurorehabil Neural Repair. 2010;24:
486-492.
19. Brunnstrom S. Movement Therapy in Hemiplegia. New York,
NY: Harper & Row; 1970.
20. Folstein MF, Folstein SE, McHugh PR. “Mini-mental State”:
a practical method for grading the cognitive state of patients
for the clinician. J Psychiatr Res. 1975;12:189-198.
21. Bohannon R, Smith M. Interrater reliability of a modified
Ashworth scale of muscle spasticity. Phys Ther. 1987;67:
206-207.
22. Taub E, Uswatte G, Pidikiti R. Constraint-induced movement
therapy: a new family of techniques with broad application to
physical rehabilitation—a clinical review. J Rehabil Res Dev.
1999;36:237-251.
23. Stoykov M, Lewis G, Corcos D. Comparison of bilateral and
unilateral training for upper extremity hemiparesis in stroke.
Neurorehabil Neural Repair. 2009;23:945-953.
24. Lin KC, Chang YF, Wu CY, Chen YA. Effects of constraintinduced therapy versus bilateral arm training on motor performance, daily functions and quality of life in stroke survivors.
Neurorehabil Neural Repair. 2009;23:441-448.
25. Winstein CJ, Miller JP, Blanton S, et al. Methods for a multisite randomized trial to investigate the effect of constraintinduced movement therapy in improving upper extremity
function among adults recovering from a cerebrovascular
stroke. Neurorehabil Neural Repair. 2003;17:137-152.
26. Fugl-Meyer AR, Jaasko L, Leyman I, et al. The post-stroke
hemiplegic patient. 1: A method for evaluation of physical
performance. Scand J Rehabil Med. 1975;7:13-31.
Downloaded from nnr.sagepub.com at UNIV OF DELAWARE LIB on November 10, 2010
6
Neurorehabilitation and Neural Repair XX(X)
27. Gladstone DJ, Danells CJ, Black SE. The Fugl-Meyer Assessment
of motor recovery after stroke: a critical review of its measurement properties. Neurorehabil Neural Repair. 2002;16:232-240.
28. Platz T, Pinkowski C, van Wijck F, Kim IH, di Bella P, Johnson G. Reliability and validity of arm function assessment
with standardized guidelines for the Fugl-Meyer Test, Action
Research Arm Test and Box and Block Test: a multicentre
study. Clin Rehabil. 2005;19:404-411.
29. Duncan PW, Bode RK, Lai SM, Perera S. Rasch analysis of a
new stroke-specific outcome scale: the Stroke Impact Scale.
Arch Phys Med Rehabil. 2003;84:950-963.
30. Huang YH, Wu CY, Hsieh YW, Lin KC. Predictors of change
in quality of life after distributed constraint-induced therapy
in patients with chronic stroke. Neurorehabil Neural Repair.
2010;24:559-566.
31. Duncan P, Reker D, Kwon S, et al. Measuring stroke impact
with the Stroke Impact Scale: telephone versus mail administration in veterans with stroke. Med Care. 2005;43:507-515.
32. Kwon S, Duncan P, Studenski S, Perera S, Lai SM, Reker D.
Measuring stroke impact with SIS: construct validity of SIS
telephone administration. Qual Life Res. 2006;15:367-376.
33. Wolf SL, Winstein CJ, Miller JP, et al. Effect of constraintinduced movement therapy on upper extremity function 3 to
9 months after stroke: the EXCITE randomized clinical trial.
JAMA. 2006;296;2095-3104.
34. Hays RD, Anderson R, Revicki D. Assessing reliability and
validity of measurement in clinical trials. In: Staquet MJ,
Hays RD, Fayers PM, eds. Quality of Life Assessments in
Clinical Trials. New York, NY: Oxford University Press;
1998:169-182.
35. Kotsis SV, Chung KC, Arbor A. Responsiveness of the
Michigan Hand Outcomes Questionnaire and the Disabilities
of the Arm, Shoulder and Hand Questionnaire in carpal tunnel
surgery. J Hand Surg Am. 2005;30A:81-86.
36. Cohen JW. Statistical Power Analysis for the Behavior Sciences. 2nd ed. Hillsdale, NJ: Lawrence Erlbaum; 1988.
37. Yeo D, Mantel H, Liu TP. Bootstrap Variance Estimation for
the National Population Health Survey. Proceedings of the
Survey Research Methods Section. Baltimore, MD: American
Statistical Association; 1999.
38. Stratford PW, Kennedy DM. Does parallel item content on
WOMAC’s pain and function subscales limit its ability to
detect change in functional status? BMC Musculoskelet Disord.
2004;5:17.
39. Kolobe TH, Palisano RJ, Straford PW. Comparison of two
outcome measures for infants with cerebral palsy and infants
with motor delays. Phys Ther. 1998;78:1062-1072.
40. Georgoudis G, Oldham JA, Watson PJ. Reliability and sensitivity measures of the Greek version of the short form of the
McGill Pain Questionnaire. Eur J Pain. 2001;5:109-118.
Downloaded from nnr.sagepub.com at UNIV OF DELAWARE LIB on November 10, 2010