Sheau-Ling Huang

Test-Retest Reproducibility and Smallest Real Difference of 5 Hand Function Tests in Patients With Stroke

Objective. To investigate the test-retest reproducibility and smallest real difference (SRD) of 3 hand strength tests (grip, palmar pinch, and lateral pinch) and 2 dexterity tests (the Box and Block test [BBT] and the Nine Hole Peg test [NHPT]) in patients with stroke. Methods. The 5 tests were administered on 62 stroke patients in 2 sessions, 3 to 7 days apart. The intraclass correlation coefficient (ICC) was used to determine the level of reproducibility between measurements on 2 sessions. The SRD was used to determine the extent of measurement error because of chance variation in individual patients. SRD percentage (SRD relative to mean score) was used to compare test-retest reliability across tests. We analyzed the group as a whole, then in 2 subgroups (hand spasticity vs none). Results. The test-retest reproducibility of all 5 tests was high for all the patients, with ICCs ranging from 0.85 to 0.98. The SRDs for the more/less affected hand were: 2.9/4.7 kg for the grip test; 1.2/1.3 kg for the palmar pinch test; 1.4/1.0 kg for the lateral pinch test; 5.5/7.8 blocks/minute for the BBT; and 32.8/6.2 seconds for the NHPT. Unacceptably high SRD percentages (>30%) were found for the affected hand using the NHPT (54%), palmar pinch (35%), and lateral pinch (34%). When comparing these indices for participants with spasticity versus none for all 5 tests, the ICCs were lower and the SRD and SRD percentage were higher for the spasticity group. Conclusions. All 5 tests demonstrated satisfactory test-retest reproducibility for a diverse group of patients with stroke. However, all tests showed higher levels of measurement error when performed with the more affected hand and in patients with hypertonicity of that hand. Thus, baseline and postrehabilitation change scores using these common tests of strength and dexterity must be interpreted with some caution, especially in poorly controlled clinical trials. Repeated measures ought to be incorporated to examine reliability within a trial that includes participants with a hypertonic hand.

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.

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 × √2 × 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.

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.

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

Abstract 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.

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.

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.

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.

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.