Test-retest reliabilities and minimal detectable changes of 5 versions of the Alzheimer's Disease Assessment Scale-Cognitive Subscale in people with dementia.

PURPOSE: To compare the test-retest reliability and minimal detectable change (MDC) of the commonly used versions of the Alzheimer's Disease Assessment Scale-Cognitive Subscale (ADAS-Cog) (the ADAS-Cog-11 (11 items), ADAS-Cog-3 (three items), ADAS-Cog-5-Subset (five items), ADAS-Cog-6-Subset (six items), and ADAS-Rasch (11 items)) in people with dementia. MATERIALS AND METHODS: A repeated-assessments design (2 weeks apart) was used to examine the ADAS-Cog-11, ADAS-Cog-3, ADAS-Cog-5-Subset, ADAS-Cog-6-Subset, and ADAS-Rasch. Participants with dementia were recruited from one hospital, one elder care center, and two day-care centers using convenience sampling. RESULTS: Fifty-two participants finished the assessments twice in two weeks. All versions showed high intraclass correlation coefficients (ICCs) (0.82-0.96), minimal standardized response means (-0.07 to 0.08) and low to acceptable MDC% (9.2-28.6%). The ADAS-Rasch had the highest ICC (0.96) and the lowest MDC%. The ADAS-Cog-3 had an ICC lower than 0.90 (0.82) and the highest MDC% (28.6%). CONCLUSIONS: The ADAS-Rasch seems to be the most reliable version of the ADAS-Cog for group- and individual-level comparisons. The ADAS-Cog-3 may be a better choice for researchers for group-level comparisons because it requires fewer items to achieve acceptable reliability. The ADAS-Cog-11, ADAS-Cog-5-Subset, ADAS-Cog-6-Subset, and ADAS-Rasch could be considered for clinical usage for individual-level comparisons.Implications for rehabilitationThe ADAS-Rasch is the most reliable version of the ADAS-Cog for group- and individual-level comparisons due to its excellent test-retest reliability, lowest random measurement error and absence of a practice effect.The ADAS-Cog-5-Subset and ADAS-Cog-6-Subset might be good substitutes for the ADAS-Rasch in clinical settings because of their comparable reliability features and superior administration efficiency.

Comparison of responsiveness of the Barthel Index and modified Barthel Index in patients with stroke.

PURPOSE: To compare the group- and individual-level responsiveness of the Barthel Index (BI) and modified BI (MBI) in patients with early subacute stroke. MATERIALS AND METHODS: The BI and MBI scores of 63, 63, and 55 patients were retrieved at 3 time points with a 3-weeks interval. The group-level responsiveness was examined using paired t-test and standardized response mean (SRM). The individual-level responsiveness was examined by the percentage of patients who achieved significant improvement exceeding the corresponding minimal detectable change. RESULTS: At the group level, the MBI showed significantly larger SRMs than did the BI in the 1st-2nd assessment (1.10 vs. 0.81 [95% CI of mean difference = 0.05-0.38]) and the 2nd-3rd assessment (0.94 vs. 0.72 [95% CI of mean difference = 0.04-0.41]). At the individual level, the MBI detected significantly more patients with significant improvement than the BI for the 1st-2nd assessments only (34.9 vs. 25.4% [95% CI of mean differences = 3.2-17.5]). CONCLUSIONS: The MBI has better responsiveness than the BI at both the group and individual levels in the patients with early subacute stroke. The MBI is recommended for clinical and research use as an outcome measure for patients with stroke.IMPLICATIONS FOR REHABILITATIONThe MBI is recommended for clinical and research applications because of its superior ability to detect subtle changes in ADL performance in patients with subacute stroke.The MBI and the BI have equal responsiveness for patients whose magnitude of improvement of ADL is substantial.

Cross-Validation of the Factorial Validity of the Stroke Impact Scale 3.0 in Patients With Stroke.

IMPORTANCE: The Stroke Impact Scale 3.0 appears to be a promising outcome measure of health-related quality of life (HRQOL) for clients with stroke. However, because the factorial validity of the Stroke Impact Scale 3.0 remains unclear, its validity is limited. OBJECTIVE: To examine the underlying structure of the Stroke Impact Scale 3.0 by comparing the currently available eight- and four-domain structures simultaneously. DESIGN: Secondary data analysis of responses to the Stroke Impact Scale 3.0 from a previous psychometric validation study. SETTING: Five general hospitals in northern and southern Taiwan. PARTICIPANTS: Two hundred sixty-three patients with stroke from rehabilitation wards (inpatients) and neurology and rehabilitation clinics (outpatients). OUTCOMES AND MEASURES: Confirmatory factor analysis was used to examine the eight- and four-domain structures of the Stroke Impact Scale 3.0. Four fit indices were considered simultaneously to examine the model fits of both structures. RESULTS: The eight- and four-domain structures of the Stroke Impact Scale 3.0 were not supported by all four indices (χ²/df = 2.7 and 5.0, comparative fit index = .79 and .86, root mean square error of approximation = .08 and .12, standardized root mean square residual = .08 and .08, respectively). The unidimensionality of each domain in the two structures was not supported. CONCLUSIONS AND RELEVANCE: Neither the eight- nor the four-domain structure of the Stroke Impact Scale 3.0 was supported, suggesting that scores may not provide valid assessments of HRQOL in clients with stroke. Further modification and validation of the Stroke Impact Scale 3.0 are warranted. WHAT THIS ARTICLE ADDS: Our findings suggest that the eight- and four-domain scores of the Stroke Impact Scale 3.0 may not be valid. Therefore, until more supporting evidence is developed, these scores should be interpreted cautiously in regard to clients' HRQOL; alternatively, other measures could be used.

Responsiveness and predictive validity of the computerized digit vigilance test in patients with stroke.

Purpose: To investigate the responsiveness and predictive validity of the computerized digit vigilance test (C-DVT) in inpatients receiving rehabilitation following stroke. Methods: Forty-nine patients completed the C-DVT and the Barthel Index (BI) after admission to and before discharge from the rehabilitation ward. The standardized response mean (SRM) was used to examine the responsiveness of the C-DVT. We used a paired t-test to determine the statistical significance of the changes in scores on the C-DVT. We estimated the predictive validity of the C-DVT with the Pearson correlation coefficient (r) to investigate the association between the scores of the C-DVT at admission and the scores of the BI at discharge. Results: Our data showed a small SRM (-0.31) and a significant difference (paired t-test, p = 0.034) between the C-DVT scores at admission and discharge. These findings indicate that the C-DVT can appropriately detect changes in sustained attention. In addition, we found a moderate association (r = 0.48) between the scores of the C-DVT at admission and the scores of the BI at discharge, suggesting the sufficient predictive validity of the C-DVT. Conclusions: Our results showed that the C-DVT had adequate responsiveness and sufficient predictive validity in inpatients receiving rehabilitation following stroke. Implications for rehabilitation The computerized digit vigilance test (C-DVT) had adequate responsiveness to be an outcome measure for assessing the sustained attention in inpatients receiving rehabilitation after stroke. The C-DVT had sufficient predictive validity to predict daily function in inpatients receiving rehabilitation after stroke.

Minimal Detectable Change on the Lawton Instrumental Activities of Daily Living Scale in Community-Dwelling Patients With Schizophrenia.

The main purpose of this study was to estimate the minimal detectable change (MDC) on the Lawton Instrumental Activities of Daily Living (LIADL) scale in community-dwelling patients with schizophrenia. Fifty-seven patients completed the LIADL assessment twice, about 14 days apart. Two scoring methods (dichotomous and polytomous) were used to record the patients' performance on the LIADL scale. The MDCs of the LIADL scale were 1.5 (dichotomous) and 4.4 (polytomous) points. The MDC percentages were 22.0% (dichotomous) and 22.5% (polytomous), both of which are within acceptable measurement errors. The test-retest reliabilities of the LIADL scale were both acceptable with two different scoring methods (dichotomous = .75; polytomous = .76). Users can choose the scoring method according to their individual needs.

Prediction of lower extremity motor recovery in persons with severe lower extremity paresis after stroke.

OBJECTIVE: To investigate the extent of motor recovery and predict the prognosis of lower extremity (LE) recovery in patients with severe LE paresis after stroke Methods: 137 patients with severe LE paresis after stroke were recruited from a local medical centre. Voluntary LE movement was assessed with the LE subscale of the Stroke Rehabilitation Assessment of Movement (STREAM-LE). Univariate and stepwise regression analyses were used to investigate 25 clinical variables (including demographic, neuroimaging, and behavioural variables) for finding the predictors of LE recovery. RESULTS: The STREAM-LE at discharge (DCSTREAM-LE) of the participants covered a very wide range (0-19). Specifically, 5.1% of the participants were nearly completely recovered, 11.7% were moderately recovered, 36.5% were slightly recovered, and 46.7% remained severely paralysed. 'Score of STREAM-LE at admission (ADSTREAM-LE)' and 'volume of lesion and oedema') were significant predictors of LE movement at discharge, explaining 25.1% of the variance of the DCSTREAM-LE (p < 0.001). CONCLUSIONS: LE motor recovery varied widely in our participants, indicating that patients' recovery might not follow simple rules. The low predictive power (about a quarter) indicates that LE motor recovery in patients with severe LE paresis after stroke was hardly predictive.

Group- and Individual-Level Responsiveness of the 3-Point Berg Balance Scale and 3-Point Postural Assessment Scale for Stroke Patients.

OBJECTIVES: To examine both group- and individual-level responsiveness of the 3-point Berg Balance Scale (BBS-3P) and 3-point Postural Assessment Scale for Stroke Patients (PASS-3P) in patients with stroke, and to compare the responsiveness of both 3-point measures versus their original measures (Berg Balance Scale [BBS] and Postural Assessment Scale for Stroke Patients [PASS]) and their short forms (short-form Berg Balance Scale [SFBBS] and short-form Postural Assessment Scale for Stroke Patients [SFPASS]) and between the BBS-3P and PASS-3P. DESIGN: Data were retrieved from a previous study wherein 212 patients were assessed at 14 and 30 days after stroke with the BBS and PASS. SETTING: Medical center. PARTICIPANTS: Patients (N=212) with first onset of stroke within 14 days before hospitalization. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Group-level responsiveness was examined by the standardized response mean (SRM), and individual-level responsiveness was examined by the proportion of patients whose change scores exceeded the minimal detectable change of each measure. The responsiveness was compared using the bootstrap approach. RESULTS: The BBS-3P and PASS-3P had good group-level (SRM, .60 and SRM, .56, respectively) and individual-level (48.1% and 44.8% of the patients with significant improvement, respectively) responsiveness. Bootstrap analyses showed that the BBS-3P generally had superior responsiveness to the BBS and SFBBS, and the PASS-3P had similar responsiveness to the PASS and SFPASS. The BBS-3P and PASS-3P were equally responsive to both group and individual change. CONCLUSIONS: The responsiveness of the BBS-3P and PASS-3P was comparable or superior to those of the original and short-form measures. We recommend the BBS-3P and PASS-3P as responsive outcome measures of balance for individuals with stroke.

Development of a Computerized Adaptive Testing System of the Functional Assessment of Stroke.

OBJECTIVE: To develop a computerized adaptive testing system of the Functional Assessment of Stroke (CAT-FAS) to assess upper- and lower-extremity (UE/LE) motor function, postural control, and basic activities of daily living with optimal efficiency and without sacrificing psychometric properties in patients with stroke. DESIGN: Simulation study. SETTING: One rehabilitation unit in a medical center. PARTICIPANTS: Patients with subacute stroke (N=301; mean age, 67.3±10.9; intracranial infarction, 74.5%). INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: The UE and LE subscales of the Fugl-Meyer Assessment, Postural Assessment Scale for Stroke Patients, and Barthel Index. RESULTS: The CAT-FAS adopting the optimal stopping rule (limited reliability increase of <.010) had good Rasch reliability across the 4 domains (.88-.93) and needed few items for the whole administration (8.5 items on average). The concurrent validity (CAT-FAS vs original tests, Pearson r=.91-.95) and responsiveness (standardized response mean, .65-.76) of the CAT-FAS were good in patients with stroke. CONCLUSIONS: We developed the CAT-FAS, and our results support that the CAT-FAS has sufficient efficiency, reliability, concurrent validity, and responsiveness in patients with stroke. The CAT-FAS can be used to simultaneously assess patients' functions of UE, LE, postural control, and basic activities of daily living using, on average, no more than 10 items; this efficiency is useful in reducing the assessment burdens for both clinicians and patients.

Comparison of construct validity of two short forms of Stroke-Specific Quality of Life scale.

BACKGROUND: No studies have compared the 2-factor structures of Wong's and Post's versions of the short-form Stroke-Specific Quality of Life (i.e., 12-item SSQOL) scale. This study compared the construct validity of 2 short-forms of the 12-item-SSQOL (not the 12-domain-SSQOL). METHODS: Data were obtained from a previous validation study of the original 49-item SSQOL in 263 patients. Construct validity was tested by confirmatory factor analysis (CFA) to examine whether the two-factor structure, including psychosocial and physical domains, was supported in both versions. The CFA tested the data-model fit by indices: chi-square χ2/df ratio, root mean square error of approximation (RMSEA), comparative fit index (CFI), nonnormative fit index (NNFI), standard root mean square residual (SRMR), and parsimony normed fit index (PNFI). Item factor loadings (cutoffs: .50) were examined. Model fit was compared using Akaike information criterion (AIC) and consistent AIC (i.e., CAIC) values. RESULTS: All model fit indices for Post's version fell within expected ranges: χ2/df ratio = 2.02, RMSEA = 0.05, CFI = 0.97, NNFI = 0.97, SRMR = 0.06, and PNFI = 0.76. In the psychosocial domain, the item factor loadings ranged from 0.46 to 0.63. In the physical domain, all items (except the language and vision items) had acceptable factor loadings (0.68 to 0.88). However, in Wong's version, none of the model indices met the criteria for good fit. In model fit comparisons, Post's version had smaller AIC and CAIC values than did Wong's version. CONCLUSIONS: All fit indices supported Post's version, but not Wong's version. The construct validity of Post's version with a 2-factor structure was confirmed, and this version of the 12-item SSQOL is recommended.

Test-retest reliability and minimal detectable change of the Beck Depression Inventory and the Taiwan Geriatric Depression Scale in patients with Parkinson's disease.

BACKGROUND: The Beck Depression Inventory II (BDI-II) and the Taiwan Geriatric Depression Scale (TGDS) are self-report scales used for assessing depression in patients with Parkinson's disease (PD) and geriatric people. The minimal detectable change (MDC) represents the least amount of change that indicates real difference (i.e., beyond random measurement error) for a single subject. Our aim was to investigate the test-retest reliability and MDC of the BDI-II and the TGDS in people with PD. METHODS: Seventy patients were recruited from special clinics for movement disorders at a medical center. The patients' mean age was 67.7 years, and 63.0% of the patients were male. All patients were assessed with the BDI-II and the TGDS twice, 2 weeks apart. We used the intraclass correlation coefficient (ICC) to determine the reliability between test and retest. We calculated the MDC based on standard error of measurement. The MDC% was calculated (i.e., by dividing the MDC by the possible maximal score of the measure). RESULTS: The test-retest reliabilities of the BDI-II/TGDS were high (ICC = 0.86/0.89). The MDCs (MDC%s) of the BDI-II and TGDS were 8.7 (13.8%) and 5.4 points (18.0%), respectively. Both measures had acceptable to nearly excellent random measurement errors. CONCLUSIONS: The test-retest reliabilities of the BDI-II and the TGDS are high. The MDCs of both measures are acceptable to nearly excellent in people with PD. These findings imply that the BDI-II and the TGDS are suitable for use in a research context and in clinical settings to detect real change in a single subject.

Effects of Transcranial Direct Current Stimulation With Sensory Modulation on Stroke Motor Rehabilitation: A Randomized Controlled Trial.

OBJECTIVE: To test whether a multistrategy intervention enhanced recovery immediately and longitudinally in patients with severe to moderate upper extremity (UE) paresis. DESIGN: Double-blind, randomized controlled trial with placebo control. SETTING: Outpatient department of a local medical center. PARTICIPANTS: People (N=25) with chronic stroke were randomly assigned to 1 of 2 groups: a transcranial direct current stimulation with sensory modulation (tDCS-SM) group (n=14; mean age ± SD, 55.3±11.4y) or a control group (n=11; mean age ± SD, 56.9±13.5y). INTERVENTIONS: Eight-week intervention. The tDCS-SM group received bilateral tDCS, bilateral cutaneous anesthesia, and high repetitions of passive movements on the paretic hand. The control group received the same passive movements but with sham tDCS and sham anesthesia. During the experiment, all participants continued their regular rehabilitation. MAIN OUTCOME MEASURES: Voluntary UE movement, spasticity, UE function, and basic activities of daily living. Outcomes were assessed at baseline, at postintervention, and at 3- and 6-month follow-ups. RESULTS: No significant differences were found between groups. However, there was a trend that the voluntary UE movement improved more in the tDCS-SM group than in the control group, with a moderate immediate effect (partial η2 [ηp2]=.14, P=.07) and moderate long-term effects (3-mo follow-up: ηp2=.17, P=.05; 6-mo follow-up: ηp2=.12, P=.10). Compared with the control group, the tDCS-SM group had a trend of a small immediate effect (ηp2=.02-.04) on reducing spasticity, but no long-term effect. A trend of small immediate and long-term effects in favor of tDCS-SM was found on UE function and daily function recovery (ηp2=.02-.09). CONCLUSIONS: Accompanied with traditional rehabilitation, tDCS-SM had a nonsignificant trend of having immediate and longitudinal effects on voluntary UE movement recovery in patients with severe to moderate UE paresis after stroke, but its effects on spasticity reduction and functional recovery may be limited.

Minimal detectable change of the Personal and Social Performance scale in individuals with schizophrenia.

The minimal detectable change (MDC) of the Personal and Social Performance scale (PSP) has not yet been investigated, limiting its utility in data interpretation. The purpose of this study was to determine the MDCs of the PSP administered by the same rater or different raters in individuals with schizophrenia. Participants with schizophrenia were recruited from two psychiatric community rehabilitation centers to complete the PSP assessments twice, 2 weeks apart, by the same rater or 2 different raters. MDC values were calculated from the coefficients of intra- and inter-rater reliability (i.e., intraclass correlation coefficients). Forty patients (mean age 36.9 years, SD 9.7) from one center participated in the intra-rater reliability study. Another 40 patients (mean age 44.3 years, SD 11.1) from the other center participated in the inter-rater study. The MDCs (MDC%) of the PSP were 10.7 (17.1%) for the same rater and 16.2 (24.1%) for different raters. The MDCs of the PSP appeared appropriate for clinical trials aiming to determine whether a real change in social functioning has occurred in people with schizophrenia.

Intrarater and Interrater Reliability of the Hierarchical Balance Short Forms in Patients With Stroke.

OBJECTIVE: To examine the intrarater and interrater reliability of a quick balance measure, the Hierarchical Balance Short Forms (HBSF), in outpatients with stroke receiving rehabilitation. DESIGN: A repeated-assessments design (1wk apart) was used to examine the intrarater and interrater reliability of the HBSF. The HBSF was administered by a single rater in the intrarater reliability study and by 2 raters in the interrater reliability study. The raters had sufficient working experience in stroke rehabilitation. SETTING: Seven teaching hospitals. PARTICIPANTS: Two independent groups of outpatients (N=106; each group, n=53) with stroke in chronic stages and in stable medical condition were recruited. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURE: HBSF. RESULTS: For the intrarater reliability study, the values of the intraclass correlation coefficient (ICC), minimal detectable change (MDC), and percentage of minimal detectable change (MDC%) were .95, 1.02, and 16.3%, respectively, for the HBSF. The 95% limits of agreement (LOA) of the HBSF ranged from -.69 to 1.19. For the interrater reliability study, the values of the ICC, MDC, and MDC% were .91, 1.22, and 18.3%, respectively, for the HBSF. The 95% LOA of the HBSF ranged from -1.01 to 1.35. CONCLUSIONS: Our results suggest that the HBSF has satisfactory intrarater and interrater reliability for assessing balance function in outpatients with stroke. The MDC values of the HBSF are useful for both researchers and clinicians to determine whether the change in balance function of an individual patient is real when administered by an individual rater or by different raters.

Convergent validity and responsiveness of the EQ-5D utility weights for stroke survivors.

OBJECTIVE: This prospective study examined the convergent validity and responsiveness of the EuroQoL-5 Dimensions Health Questionnaire (EQ-5D) utility weights in stroke survivors at the subacute stage. METHODS: Repeated assessments were conducted in rehabilitation wards of a medical centre. A study cohort was recruited from inpatients (n = 478). A total of 342 participants (71.5%) completed 2 assessments; 1 at ward admission and 1 before hospital discharge. Outcome measures, including the Barthel Index (BI), Patient Health Questionnaire (PHQ-9) and EQ-5D, were administered at ward admission and before hospital discharge. RESULTS: The validity of the EQ-5D utility weights was assessed by comparison with the scores of the BI and PHQ-9. The absolute values of Pearson correlation coefficients ranged from 0.40 to 0.52 for the association of EQ-5D utility weights with BI scores and PHQ-9 scores at admission and before hospital discharge. The EQ-5D utility weights had a moderate effect size (0.76), moderate standardized response mean (0.74), and a significant difference (paired t-value = 13.7, p < 0.001) between baseline and follow-up in their ability to detect changes in the health status of stroke survivors staying in a rehabilitation ward. CONCLUSION: This study supports the use of the EQ-5D utility weights as a valid and responsive instrument for performing cost-utility analyses of stroke survivors, including those with higher levels of dependence, at the subacute stage.

Psychometric properties of the Five-Digit Test in patients with stroke.

PURPOSE: To examine the ecological validity, predictive validity, and responsiveness of the Five Digit Test (FDT) in patients with stroke. METHODS: We included inpatients with stroke (n = 144, 114 and 105 in the ecological validity, predictive validity, and responsiveness analysis, respectively) in the study. At admission, the FDT and Barthel Index (BI) were assessed; at discharge, the FDT, BI, Postural Assessment Scale for Stroke Patients (PASS), and Mobility Subscale of the Stroke Rehabilitation Assessment of Movement (MO-STREAM) were assessed. RESULTS: In the ecological validity analysis, the scores of the selective and alternating attention indices of the FDT were moderately correlated with those of the BI at admission and discharge (Spearman ρ = -0.38 to -0.45). In the predictive validity analysis, the scores of the two attention indices of the FDT at admission were moderately correlated with the scores of the BI, PASS, and MO-STREAM at discharge (ρ = -0.33 to -0.45). In the responsiveness analysis, the two attention indices of the FDT between admission and discharge had large differences (success rate difference = 0.56-0.67, Wilcoxon Z = -5.90 to -6.60). CONCLUSION: Our results indicate that the selective and alternating attention indices of the FDT have acceptable ecological validity, predictive validity, and good responsiveness in patients with stroke. IMPLICATIONS FOR REHABILITATION: The Five Digit Test (FDT), an efficient and culture-free assessment tool, has been used to assess selective attention and alternating attention The selective index and alternating attention index of the FDT showed acceptable ecological validity, predictive validity, and good responsiveness in patients with stroke.

Smallest real difference of 2 instrumental activities of daily living measures in patients with chronic stroke.

OBJECTIVE: To estimate the smallest real difference (SRD) values of 2 instrumental activities of daily living measures (the Nottingham Extended Activities of Daily Living [NEADL] and the Frenchay Activities Index [FAI]) in patients with chronic stroke. DESIGN: Test-retest reliability study. SETTING: Physical rehabilitation units of 5 hospitals. PARTICIPANTS: Chronic stroke patients (N=52; 37 men, 15 women) who were discharged from the hospital for more than 6 months. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Both measures were administered twice about 2 weeks apart to participants. The SRD was calculated on the basis of standard error of measurement: SRD = 1.96 × âˆš2 × Standard error of measurement. SRD% (the value of SRD divided by total score of a measure) was used to compare measurement errors across both measures. Reproducibility between successive measurements of the measures was investigated with intraclass correlation coefficients (ICCs). RESULTS: The SRD (SRD%) values of the NEADL and the FAI were 12.0 (21.1%) and 6.7 (14.9%), respectively. Test-retest reproducibility of both measures was high (ICC: NEADL=.89, FAI=.89). CONCLUSIONS: Because of substantial SRD values of the NEADL and the FAI, prospective users should be cautious in using both measures to detect real change for a single subject.

Optimal scoring methods of hand-strength tests in patients with stroke.

The purpose of this study was to determine the optimal scoring methods for measuring strength of the more-affected hand in patients with stroke by examining the effect of reducing measurement errors. Three hand-strength tests of grip, palmar pinch, and lateral pinch were administered at two sessions in 56 patients with stroke. Five scoring methods were used to present the strength scores. The smallest real difference was used to provide information on the measurement error. The smallest real difference percentage was used to compare the effect on minimizing the error. Using mean score of tests for nonspastic patients carried out at least twice was found to be advisable to minimize measurement errors in the grip, palmar pinch, and lateral pinch tests. However, the use of hand-strength tests for patients with spasticity is limited because of the relatively high measurement errors.

Minimal detectable change of the timed "up & go" test and the dynamic gait index in people with Parkinson disease.

BACKGROUND: The minimal detectable change (MDC) is the smallest amount of difference in individual scores that represents true change (beyond random measurement error). The MDCs of the Timed "Up & Go" Test (TUG) and the Dynamic Gait Index (DGI) in people with Parkinson disease (PD) are largely unknown, limiting the interpretability of the change scores of both measures. OBJECTIVE: The purpose of this study was to estimate the MDCs of the TUG and the DGI in people with PD. DESIGN: This investigation was a prospective cohort study. METHODS: Seventy-two participants were recruited from special clinics for movement disorders at a university hospital. Their mean age was 67.5 years, and 61% were men. All participants completed the TUG and the DGI assessments twice, about 14 days apart. The MDC was calculated from the standard error of measurement. The percentage MDC (MDC%) was calculated as the MDC divided by the mean of all scores for the sample. Furthermore, the intraclass correlation coefficient was used to examine the reproducibility between testing sessions (test-retest reliability). RESULTS: The respective MDC and MDC% of the TUG were 3.5 seconds and 29.8, and those of the DGI were 2.9 points and 13.3. The test-retest reliability values for the TUG and the DGI were high; the intraclass correlation coefficients were .80 and .84, respectively. LIMITATIONS: The study sample was a convenience sample, and the participants had mild to moderately severe PD. CONCLUSIONS: The results showed that the TUG and the DGI have generally acceptable random measurement error and test-retest reliability. These findings should help clinicians and researchers determine whether a change in an individual patient with PD is a true change.

Cross-cultural adaptation and validation of the Quebec User Evaluation of Satisfaction with Assistive Technology (QUEST 2.0): the development of the Taiwanese version.

OBJECTIVE: To develop and validate a cross-cultural version of the Quebec User Evaluation of Satisfaction with Assistive Technology (QUEST 2.0) for users of assistive technology devices in Taiwan. DESIGN: A cross-sectional survey. PROCEDURES: The standard cultural adaptation procedure was used for questionnaire translation and cultural item design. A field test was then conducted for item selection and psychometric properties testing. SUBJECTS: One hundred and five volunteer assistive device users in community. MAIN OUTCOME MEASURES: A questionnaire comprising 12 items of the QUEST 2.0 and 16 culture-specific items. RESULTS: One culture-specific item, 'Cost', was selected based on eight criteria and added to the QUEST 2.0 (12 items) to formulate the Taiwanese version of QUEST 2.0 (T-QUEST). The T-QUEST consisted of 13 items which were classified into two domains: device (8 items) and service (5 items). The internal consistencies of the device, service and total T-QUEST scores were 0.87, 0.84 and 0.90, respectively. The device, services and total T-QUEST scores achieved good test-retest stability (intraclass correlation coefficient (ICC) 0.90, 0.97, 0.95). Exploratory factor analysis revealed that T-QUEST had a two-factor structure for device and service in the construct of user satisfaction (53.42% of the variance explained). CONCLUSIONS: Users of assistive device in different culture may have different concerns regarding satisfaction. T-QUEST is the first published version of QUEST with culture-specific items added to the original translated items of QUEST 2.0. T-QUEST was a valid and reliable tool for measuring user satisfaction among Mandarin-speaking individuals using various kinds of assistive devices.