Leah Nof

Test-Retest Reliability and Minimal Detectable Change Scores for the Timed “Up & Go” Test, the Six-Minute Walk Test, and Gait Speed in People With Alzheimer Disease

Background: With the increasing incidence of Alzheimer disease (AD), determining the validity and reliability of outcome measures for people with this disease is necessary. Objective: The goals of this study were to assess test-retest reliability of data for the Timed “Up & Go” Test (TUG), the Six-Minute Walk Test (6MWT), and gait speed and to calculate minimal detectable change (MDC) scores for each outcome measure. Performance differences between groups with mild to moderate AD and moderately severe to severe AD (as determined by the Functional Assessment Staging [FAST] scale) were studied. Design: This was a prospective, nonexperimental, descriptive methodological study. Methods: Background data collected for 51 people with AD included: use of an assistive device, Mini-Mental Status Examination scores, and FAST scale scores. Each participant engaged in 2 test sessions, separated by a 30- to 60-minute rest period, which included 2 TUG trials, 1 6MWT trial, and 2 gait speed trials using a computerized gait assessment system. A specific cuing protocol was followed to achieve optimal performance during test sessions. Results: Test-retest reliability values for the TUG, the 6MWT, and gait speed were high for all participants together and for the mild to moderate AD and moderately severe to severe AD groups separately (intraclass correlation coefficients ≥.973); however, individual variability of performance also was high. Calculated MDC scores at the 90% confidence interval were: TUG=4.09 seconds, 6MWT=33.5 m (110 ft), and gait speed=9.4 cm/s. The 2 groups were significantly different in performance of clinical tests, with the participants who were more cognitively impaired being more physically and functionally impaired. Limitations: A single researcher for data collection limited sample numbers and prohibited blinding to dementia level. Conclusions: The TUG, the 6MWT, and gait speed are reliable outcome measures for use with people with AD, recognizing that individual variability of performance is high. Minimal detectable change scores at the 90% confidence interval can be used to assess change in performance over time and the impact of treatment.

Clinometric properties of the six-minute walk test in individuals undergoing rehabilitation poststroke

The 6-minute walk test (6MWT) is commonly used to measure walking ability. The purpose of this study was to determine the test-retest reliability and concurrent and construct validity of the 6MWT in patients who were actively undergoing inpatient rehabilitation poststroke. Thirty-seven patients undergoing inpatient rehabilitation after a stroke participated; mean age was 66.3 years and mean time since stroke was 33.7 days. Patients underwent two 6MWT trials with 1–3 days between trials. Additional outcome measures taken were gait speed and the Functional Independence MeasureTM (FIMTM). The 6MWT exhibited high test-retest reliability; ICC2,1 0.973 (95% CI=0.925–0.988) and a minimal detectable change (MDC90) of 54.1 m. The 6MWT was strongly to moderately correlated with gait speed (r=0.89), locomotion (walk) FIMTM (r=0.69), and motor FIMTM (r=0.52). The 6MWT is a clinically useful measure of walking ability poststroke. It is reliable and is related to other measures of walking ability and function that are commonly used during rehabilitation after stroke.

Test-Retest Reliability and Construct Validity of the Tinetti Performance-Oriented Mobility Assessment in People With Stroke.

Background and Purpose: The Tinetti Performance-Oriented Mobility Assessment (POMA) is commonly used to measure balance ability in older adults. The purpose of this study was to determine the test-retest reliability and minimal detectable change (MDC) of the POMA and explore its cross-sectional and longitudinal construct validity for use in people early after stroke. Methods: Participants were recruited if they had a first documented stroke and were receiving physical therapy during inpatient rehabilitation. The POMA, gait speed, and motor Functional Independence Measure (FIM) scores were collected at admission and at discharge from inpatient rehabilitation. A second trial of the POMA was conducted 1 day after the first trial for reliability analysis. Correlations (Spearman &rgr;) between raw scores of admission and discharge outcome measures, as well as change in scores between admission and discharge, were used to explore the construct validity of the POMA. Results: Fifty-five people, with average age of 75 ± 11 years, who had experienced first documented stroke participated in the study and began inpatient physical therapy at a mean of 8 ± 5 days poststroke. Test-retest reliability intraclass correlation coefficient (ICC2,1) was 0.84 and MDC was 6 points. The POMA scores were moderately correlated to motor FIM and gait speed scores at admission (rs = 0.55 and 0.70) and discharge (rs = 0.55 and 0.82.) Change scores of all 3 measures had a fair correlation (rs = 0.28–0.51). Discussion and Conclusions: Test-retest reliability and MDC of the POMA in people with stroke is similar to previous research in older adult long-term care residents. Results support cross-sectional and longitudinal construct validity of the POMA in persons early after stroke and demonstrate validity and reliability to measure balance ability in this population. Video Abstract available (see Video, Supplemental Digital Content 1, http://links.lww.com/JNPT/A39) for more insights from the authors.

The gross motor function classification system for cerebral palsy and single-event multilevel surgery: is there a relationship between level of function and intervention over time?

Background The purpose of this study was to determine what effect, if any, an intervention such as Single-event multilevel orthopaedic surgery (SEMLS) might have on the relative stability of the gross motor function classification system (GMFCS) for cerebral palsy over a 5-year time period. Methods Eighty-four children with spastic cerebral palsy who underwent SEMLS were included. The patients had an average of 5.45 procedures during surgery. Mean age at the time of surgery was 6 years. Two blinded physical therapists applied the GMFCS to functional descriptions extracted from outpatient clinical records. The patients were rated preoperatively, 1, 2, and 5 years postoperatively. Results Interrater reliability was high, Kw=0.90. Friedmans nonparametric repeated measures analysis of variance was conducted comparing the GMFCS classification levels of the patients preoperatively and 1, 2, and 5 years after SEMLS. The patients as a group showed a significant change to a lower GMFCS classification postsurgery (P<0.001). Children classified at levels I and V of the GMFCS preoperatively showed lesser likelihood of changing functional levels postsurgery. Conclusions The results of this investigation support the concept that interventions, especifically SEMLS, can affect the stability of the GMFCS classification. The majority of children in this study showed changes in gross motor function classification as reflected by lower GMFCS scores after SEMLS intervention. We also found that changes were maintained over a period of 5 years. The results of this study suggest that certain interventions, such as SEMLS, might have an effect on the stability of the GMFCS and that effect may be level-dependent. Level of Evidence Retrospective Study by Review of Medical Records. Level III in the Therapeutic Study investigating results of treatment category.