Accelerometer-based gait characteristics and their discrimination of gait independence in inpatients with subacute stroke.

BACKGROUND: Gait analysis using inertial measurement devices can identify multifaceted gait disorders after a stroke. Although the usefulness of gait assessment using inertial measurement devices has been reported, its accuracy in discriminating gait independence in patients hospitalized for subacute stroke has not yet been validated. RESEARCH QUESTION: Can trunk acceleration indices discriminate between dependent and independent walking in patients with subacute stroke? METHODS: Thirty-five patients with subacute stroke (mean ± standard deviation, 75.5 ± 9.8 years, 19 males), who were able to understand instructions, had a premorbid modified Rankin scale <3, and were able to walk 16 m straight ahead under supervision were included. The stride regularity, harmonic ratio, and normalized root mean square of trunk accelerations were measured in three directions (mediolateral, vertical, and anterioposterior) during comfortable walking. The Functional Ambulation Categories were used as the dependent variable to classify the patients into two groups (dependent and independent walking groups), and each trunk acceleration index was used as the independent variable to calculate the area under the curve using receiver operating characteristic curves. RESULTS: Twelve patients were in the dependent group and 23 were in the independent group. The normalized root mean square in both the mediolateral and vertical directions were excellent discriminators of walking independence, with an area under the curve greater than 0.8. The cutoff values (sensitivity/specificity) were 2.20 m2/s2 (0.783/0.833) and 2.82 m2/s2 (0.739/0.833), respectively. SIGNIFICANCE: The magnitude of vertical and lateral acceleration during gait in patients with subacute stroke, has excellent accuracy in discriminating between dependent and independent gaits. The results of this study will be useful for inexperienced clinicians working with stroke patients presenting with gait disturbances to accurately determine gait independence based on objective data.

Clinical prediction rules for multi surfaces walking independence using the Berg Balance Scale or Mini-Balance Evaluation Systems Test in persons with stroke.

BACKGROUND: A Clinical prediction rule (CPR) for determining multi surfaces walking independence in persons with stroke has not been established. OBJECTIVES: To develop a CPR for determining multi surfaces walking independence in persons with stroke. METHODS: This was a multicenter retrospective analysis of 419 persons with stroke. We developed a Berg Balance Scale (BBS)-model CPR combining the BBS, comfortable walking speed (CWS) and cognitive impairment, and a Mini-Balance Evaluation Systems Test (Mini-BESTest)-model CPR combining the Mini-BESTest, CWS, and cognitive impairment. A logistic regression analysis was conducted with multi surfaces walking independence as the dependent variable and each factor as an independent variable. The identified factors were scored (0, 1) based on reported cutoff values. The CPR's accuracy was verified by the area under the curve (AUC). We used a bootstrap method internal validation and calculated the CPR's posttest probability. RESULTS: The logistic regression analysis showed that the BBS, CWS, and cognitive impairment were factors in the BBS model, and the Mini-BESTest was a factor in the Mini-BESTest model. The CPRs were 0-3 points for the BBS model and 0-1 points for the Mini-BESTest model. The AUCs (bootstrap mean AUC) of the CPR score were 0.89 (0.90) for the BBS model and 0.72 (0.72) for the Mini-BESTest model. The negative predictive value (negative likelihood ratio) was 97% (0.054) for CPR scores < 2 for the BBS model and 94% (0.060) for CPR scores < 1 for the Mini-BESTest model. CONCLUSIONS: The CPR developed herein is useful for determining multi surfaces walking independence.

Minimal detectable change in inertial measurement unit-based trunk acceleration indices during gait in inpatients with subacute stroke.

Gait analysis using inertial measurement units (IMU) provides a multifaceted assessment of gait characteristics, but minimal detectable changes (MDC), the true change beyond measurement error, during gait in patients hospitalized with subacute stroke has not been clarified. This study aimed to determine the MDC in IMU-based trunk acceleration indices during gait in patients hospitalized with subacute stroke. Nineteen patients with subacute stroke (mean ± SD, 75.4 ± 10.9 years; 13 males) who could understand instructions, had a pre-morbid modified Rankin Scale < 3 and could walk straight for 16 m under supervision were included. As trunk acceleration indices, Stride regularity, harmonic ratio (HR), and normalized root mean square (RMS) during gait were calculated on three axes: mediolateral (ML), vertical (VT), and anterior-posterior (AP). MDC was calculated from two measurements taken on the same day according to the following formula: MDC = standard error of measurement × 1.96 × 2. The MDCs for each trunk acceleration index were, in order of ML, VT, and AP: 0.175, 0.179, and 0.149 for stride regularity; 0.666, 0.741, and 0.864 for HR; 4.511, 2.288, and 2.680 for normalized RMS. This finding helps determine the effectiveness of rehabilitation interventions in the gait assessment of patients with stroke.

Minimal important change in the Berg Balance Scale in older women with vertebral compression fractures: A retrospective multicenter study.

BACKGROUND: Vertebral compression fractures, which are commonly associated with older age and osteoporotic fractures, have an increased risk of re-fracture. Therefore, improving balance is important to prevent falls. The minimal important change (MIC) has been recommended for interpreting clinically meaningful changes in rating scales. The MIC of the Berg Balance Scale (BBS) for use in older women with vertebral compression fractures has not been established. OBJECTIVE: To identify the MIC of the BBS that can be used in older women with vertebral compression fractures using predictive modeling methods and the receiver-operating characteristic (ROC)-based method. DESIGN: A retrospective longitudinal multicenter study. PATIENTS: Sixty older women (mean age ± standard deviation: 84.1 ± 7.0 years) with vertebral compression fractures who were unable to ambulate independently on a level surface. METHODS: A change of one point in the Functional Ambulation Category (FAC) was used as an anchor to calculate the MIC of the BBS based on the change between admission and discharge. We calculated the MIC for the women whose FAC score improved by ≥1 point. We used three anchor-based methods to examine the MIC: the ROC-based method (MICROC ), the predictive modeling method (MICpred ), and the MICpred -based method adjusted by the rate of improvement and reliability of transition (MICadj ). RESULTS: Thirty-nine women comprised the "important change" group based on their FAC score improvement. In this group, the MICROC (95% confidence interval [CI]) value of the BBS was 10.0 points (5.5-15.5), with an area under the curve of 0.71. The MICpred (95% CI) value was 9.7 (8.1-11.0), and the MICadj (95% CI) was 7.0 (5.5-8.5) points. CONCLUSION: For women with vertebral compression fractures who are unable to ambulate independently, a 7.0-point improvement in the BBS score may be a useful indicator for reducing the amount of assistance required for walking.

Predictive discriminative accuracy of walking abilities at discharge for community ambulation levels at 6 months post-discharge among inpatients with subacute stroke.

[Purpose] This study aimed to compare the predictive accuracy of walking ability at discharge among subacute stroke inpatients at 6 months post-discharge in terms of community ambulation level and establish optimal cut-off values. [Participants and Methods] This prospective observational study included 78 patients who completed follow-up assessments. Patients were classified into three groups based on the Modified Functional Walking Category (household/most limited community walkers, least limited community walkers, and unlimited community walkers) obtained by telephone survey at 6 months post-discharge. Predictive accuracy and cut-off values for discriminating among groups were calculated from 6-minute walking distance and comfortable walking speed measured at the time of discharge using receiver operating characteristic curves. [Results] Between household/most limited and least limited community walkers, 6-minute walking distance and comfortable walking speed offered similar predictive accuracy (area under the curve, 0.6-0.7), with cut-off values of 195 m and 0.56 m/s, respectively. Between least limited and unlimited community walkers, the areas under the curve were 0.896 for 6-minute walking distance and 0.844 for comfortable walking speed, with cut-off values of 299 m and 0.94 m/s, respectively. [Conclusion] Walking endurance and walking speed among inpatients with subacute stroke provided superior predictive accuracy for unlimited community walkers at 6 months post-discharge.

Relationship between gait regularity and harmony, and gait speed at discharge in inpatients with subacute stroke.

[Purpose] Accelerometry indices are a promising and simple method to quantify gait stability. However, the long-term relationship between gait stability and walking ability in patients with stroke has not been fully investigated. The purpose of this study was to longitudinally examine the relationship between gait regularity and harmony at admission and gait speed at discharge in inpatients with subacute mild stroke. [Participants and Methods] Sixteen patients with subacute stroke (median age, 69.5 years [1st-3rd interquartile range, 58.0-73.8 years]; 13 males) were enrolled in the study. A Spearman's rank correlation coefficient was calculated for step regularity, stride regularity, the harmonic ratio at admission, and the walking speed at discharge. We also calculated the partial rank order correlation, controlling for balance ability. [Results] The vertical step regularity, harmonic ratio, and anterior-posterior harmonic ratio were all positively correlated with the walking speed at discharge. Positive correlations with vertical step regularity and harmonic ratio were found in partial rank order correlations when controlled for balance ability. [Conclusion] Vertical step regularity and gait harmony had predictive validity for discharge gait speed in patients with subacute stroke.

Cut-off values and sub-items of the Berg Balance Scale for walking-aid use in hospitalized older adults with a hip fracture: a retrospective analysis.

OBJECTIVE: To identify the Berg Balance Scale (BBS) values that can be used to discriminate the use of a walking aid and the BBS sub-items that reveal the differences in the use of walking aids among hospitalized older adults with a hip fracture. METHODS: The cases of 77 older adults (age 80.8 ± 7.5 years) with a hip fracture who were able to walk independently in the hospital were retrospectively analyzed. A receiver operating characteristic curve (AUC) analysis was used to identify BBS scores that optimized the identification of subjects with different levels of aids. The BBS sub-items identifying differing among the walking aids were identified by a classification and regression tree analysis. RESULTS: The BBS scores were highest for no aid, a cane, and a walker, in that order. The ability to walk without an aid and the ability to walk without a walker showed moderate AUCs (0.824 and 0.865) with cutoff values of 51.5 and 45.5 points, respectively. The sub-items identified were Turning 360° (4 vs. < 4 points) as the best discriminator for using/not using a cane and Stool Stepping (≥ 2 vs. < 2 points) for using a cane or walker. CONCLUSION: The BBS is useful for determining whether to discontinue the use of a walker in individuals with a hip fracture.

The minimal clinically important difference of the mini-balance evaluation systems test in patients with early subacute stroke.

BACKGROUND: There is insufficient evidence regarding the minimal clinically important difference (MCID) of the Mini-Balance Evaluation Systems Test (Mini-BESTest). OBJECTIVE: To determine the MCID of the Mini-BESTest in patients with early subacute stroke. PATIENTS AND METHODS: In this prospective cohort study, the Mini-BESTest score of 50 patients with stroke was obtained within 1 week of their admission, their Mini-BESTest and Global Rating of Change Scale (GRCS) scores were obtained at discharge. The GRCS scores were reported by both the patients and their physical therapists. We evaluated the correlation between the Mini-BESTest change scores and the GRCS by determining Spearman's rank correlation coefficient. The MCID was calculated using 0.5× standard deviation (SD) for the distribution method and the change difference and receiver operating curve (ROC) for the anchor method. RESULTS: The mean (SD) number of days between evaluations was 15.4 (4.8), and the Mini-BESTest score at admission was 17.7 (5.2) and 23.1 (3.5) at discharge. The correlation between the GRCS and the change in the Mini-BESTest score was 0.28 (p = .04) for the patients and 0.54 (p < .001) for the therapists. The MCID based on the distribution method was 3 points for 0.5× SD. The MCID values based on the anchor method were 2.3 for the change difference and 0.5 for the ROC in the patient-rated GRCS, and 4.2 for the change difference and 4.5 for the ROC in the physical therapist-rated GRCS. CONCLUSIONS: The MCID based on the anchor method was 4.2-4.5 points, and the MCID based on the distribution method was 2.3 points.

Berg Balance Scale is a Valid Measure for Plan Interventions and for Assessing Changes in Postural Balance in Patients with Stroke.

OBJECTIVES: After confirming the measurement properties of the Berg Balance Scale (BBS) in patients with stroke by conducting a Rasch analysis, this study sought: (i) to generate a keyform as a tool for goal-setting and intervention-planning; and (ii) to determine the appropriate strata for separating patients' postural balance ability. DESIGN: Methodological analyses of cross-sectional study data. PATIENTS: A pooled sample of 156 patients with stroke: mean (standard deviation) age 74.4 (12.9) years. METHODS: This study evaluated the BBS's rating scale structure, unidimensionality, and measurement accuracy (0: unable to perform or requiring help, to 4: normal performance) and then generated a keyform and strata. RESULTS: The BBS rating scale fulfilled the category functioning criteria. Principal component analysis of standardized residuals confirmed the unidimensionality of the test. All items fit the Rasch analysis. Person ability-item difficulty matching was good. Person reliability was 0.96, and the patients were divided into 9 strata. The keyform for the BBS will enable clinicians and investigators to estimate patients' postural balance ability and monitor their progress. CONCLUSION: The BBS has strong measurement properties. This study generated both a keyform that can contribute to clinicians' decision-making in goalsetting and intervention-planning and strata that can facilitate understanding of patients' abilities.

Development of Cut-off Values on the Berg Balance Scale for Predicting Walking Independence in Older Adults with Hip Fracture.

Objectives: The aim of the current study was to identify a cut-off value for predicting walking independence at discharge in older adults with hip fracture based on their Berg Balance Scale (BBS) score at admission to a convalescent rehabilitation ward. Methods: This was a retrospective, multicenter, observational study of 187 older adults with hip fractures (mean age 83.7, range 66-97 years). Data was collected on the patients' age, sex, treatment, and physical function evaluation. An ordinal logistic regression analysis was used to identify predictors associated with the degree of independence in walking at discharge. Receiver operating characteristic curves were used to estimate cut-off values to predict independent and supervised walking at discharge based on the BBS score at admission. The accuracy of the classification was assessed using the area under the curve (AUC). Results: The BBS score at admission was a significant factor predicting the degree of walking independence at discharge (odds ratio = 1.09, 95%CI: 1.06-1.11). The cut-off values of the BBS score at admission for predicting independent walking and supervised walking at discharge were 28 points (AUC = 0.76, 95%CI: 0.69-0.83) and 21 points (AUC = 0.84, 95%CI: 0.77-0.91), respectively. Conclusions: The BBS scores of older adults with hip fracture on admission to a rehabilitation ward are useful for predicting the degree of independence in walking at discharge and can help to structure therapy according to the predicted degree of independence.

Item distribution of the Berg Balance Scale in older adults with Hip fracture: a Rasch analysis.

INTRODUCTION: Balance impairment occurs after a hip fracture, but the characteristics of the impairment are not clear. OBJECTIVE: To investigate the uni-dimensionality, fit statistics, and item difficulty of the Berg Balance Scale (BBS) in older adults with hip fracture by conducting a Rasch analysis. METHODS: This was an observational cross-sectional study. The 254 participants were all ≥ 65 years old and had been hospitalized for rehabilitation after a unilateral hip fracture incurred during a fall. We collected their BBS scores at the time of hospital discharge and conducted a Rasch analysis to examine the uni-dimensionality, fit statistics, and item difficulty. RESULTS: The principal component analysis (PCA) of the Rasch model demonstrated that the BBS is uni-dimensional. The information-weighted mean square (MnSq) fit statistic was within the range of fit criteria for all items. The underfit item of the outlier-sensitive MnSq fit statistics was "Standing unsupported eyes closed" with the MnSq of 2.06. The difficult items were in order of logits: "Standing on one leg" (logits = 4.01); "Step tool" (logits = 2.74); and "Turn 360°" (logits = 2.61). CONCLUSION: The BBS is uni-dimensional and conforms with the Rasch model. The BBS most difficult items for older adults with a hip fracture required one-legged support and dynamic balance.

Minimal clinically important difference of the Berg Balance Scale and comfortable walking speed in patients with acute stroke: A multicenter, prospective, longitudinal study.

OBJECTIVE: To determine the minimal clinically important difference between the Berg Balance Scale and comfortable walking speed in acute-phase stroke patients. DESIGN: Multicenter, prospective, longitudinal study. SETTING: Inpatient acute stroke rehabilitation. SUBJECTS: Seventy-five patients with acute stroke, mean (SD) age 71.7 (12.2) years. INTERVENTION: Inpatients with acute stroke were assessed with the Berg Balance Scale and comfortable walking speed before and after rehabilitation. Physiotherapy was conducted to improve balance and gait over a 2-week period: an average of 40 min/day on weekdays and 20 min/day on weekends and holidays. MAIN MEASURES: The patients' Berg Balance Scale, comfortable walking speed, Global Rating of Change scale (patient-rated and physiotherapist-rated), and motor score of the Functional Independence Measure were obtained. Minimal clinically important differences were estimated using both anchor- (receiver operating characteristic curves and change difference) and distribution-based approaches (minimal detectable change and 0.5× the change score [SD]). RESULTS: The baseline scores were 31.2 (18.9) for the Berg Balance Scale and 0.79 (0.35) m/s for comfortable walking speed. The minimal clinically important difference in the Berg Balance Scale was 6.5-12.5 points by the anchor-based approach and 2.3-4.9 points by the distribution-based approach. The minimal clinically important difference in comfortable walking speed was 0.18-0.25 m/s by the anchor-based and 0.13-0.15 m/s by the distribution-based approach. CONCLUSIONS: A change of 6.5-12.5 points in the Berg Balance Scale and 0.18-0.25 m/s in the comfortable walking speed is required in these measurements' anchor-based minimal clinically important differences to be beyond measurement error, and to be perceptible by both patients and clinicians.

Relationship of the brief-balance evaluation systems test with physical functioning and activities of daily living: A cross-sectional study among hospitalized acute stroke patients.

BACKGROUND: The Brief-Balance Evaluation Systems Test (Brief-BESTest) has the potential to be used effectively for interventions on specific balance components. However, it has not been utilized for acute stroke cases. OBJECTIVE: This study determined the characteristics of the distribution of the Brief-BESTest scores of patients who suffered acute stroke and examined its relationship with physical function and activities of daily living ability. METHODS: The Brief-BESTest, sub-items of Stroke Impairment Assessment Set (SIAS), and Functional Independence Measure (FIM) were conducted among 41 hospitalized acute stroke patients (71.3±9.5 years, 32 males). The skewness of the Brief-BESTest and Spearman's rank correlation (ρ) between Brief-BESTest, SIAS, and FIM were analyzed. RESULTS: The skewness of the total score of the Brief-BESTest was -0.038. There were no ceiling or floor effects. The total score of the Brief-BESTest had a weak positive correlation with the SIAS lower extremity motor function (ρ= 0.457) and muscle tone (ρ= 0.374), and the total score on FIM (ρ= 0.365). Each sub-item of the Brief-BESTest was associated with different physical functions. CONCLUSIONS: The Brief-BESTest was unaffected by floor and ceiling functions among hospitalized acute stroke patients, and different physical functions were associated with each balance component.

Minimal clinically important difference of the Berg Balance Scale score in older adults with hip fractures.

PURPOSE: The minimal clinically important difference (MCID) is the smallest clinically significant difference in treatment identified as crucial to the patient. There is no known MCID for the Berg Balance Scale (BBS), which measures balance function in patients with hip fractures. We aimed to calculate the MCID of the BBS in older adults with hip fractures. MATERIALS AND METHODS: This is a retrospective multicenter clinical study that included 187 older adults with hip fractures. MCID was calculated using functional ambulation categories (FACs), which were used as anchors for the change in BBS scores between admission and discharge. MCID was calculated as an improvement for more than one point and as a substantial change for improvement for more than two points in the FAC. RESULTS: MCID of the BBS was 11.5 points and that of the substantial change was 18.5 points, with an area under the curve of 0.76 and 0.81, respectively. CONCLUSIONS: MCID for the BBS was 11.5 points in older adults with hip fractures. In addition, an improvement of more than 18.5 points in BBS can be considered a substantial change. These values may be useful in determining meaningful balance function improvement.Implications for rehabilitationHip fractures are a common injury for the older adults, and improvement in gait function has a bearing on prognosis.The effectiveness of meaningful rehabilitation is possible to determine by clarifying the minimal clinically important difference in balance function, which is important for the acquisition of gait.An improvement of 11.5 points or more on the Berg Balance Scale in an older adult with a hip fracture is considered a meaningful effect.

The minimal clinically important difference in Berg Balance Scale scores among patients with early subacute stroke: a multicenter, retrospective, observational study.

BACKGROUND: Balance dysfunction is common in stroke patients. The Berg Balance Scale (BBS) is useful for evaluating the balance function of stroke patients, and it can estimate the minimal clinically important difference (MCID) in balance. BBS scores differ among stroke patients depending on whether they require walking assistance. The MCID should thus be estimated separately for patients who require assistance and those who do not. OBJECTIVES: To estimate the MCID of individuals who have had an early subacute stroke and require a walking aid and those who do not, to assist the clinical determination of the effectiveness of therapy. METHODS: This was a retrospective clinical analysis of 80 early subacute stroke patients. We estimated the MCID by using the Functional Ambulation Categories (FAC) as anchors for changes in BBS scores during a 1-month period. The MCID was estimated based on a cutoff score for separating the patients who achieved a FAC change ≥1 point on receiver operator characteristic curves. The area under the curve (AUC) was used to measure the discrimination accuracy. The MCID was estimated for the patients who needed walking assistance and those who did not. RESULTS: The estimated MCID of BBS scores in the assisted-walking group was 5 points and the AUC was 0.84 (p < .01); the corresponding values in the unassisted-walking group were 4 points and 0.62 (p = .26). CONCLUSIONS: For early subacute stroke patients who require assistance to walk, a 5-point improvement in the BBS score is a useful indicator for reducing the amount of assistance.