Dataset Information

Minimal important difference and responsiveness of 2-minute walk test performance in people with COPD undergoing pulmonary rehabilitation.

ABSTRACT: BACKGROUND AND OBJECTIVES:Field exercise tests (eg, 6-minute walk test [6MWT]) are important measures of functional exercise capacity in people with COPD. Shorter tests such as the 2-minute walk test (2MWT) may offer advantages in some populations but lack information about responsiveness to change. This study examined responsiveness, minimal important difference (MID), test-retest reliability, and construct validity of the 2MWT in people with stable COPD attending outpatient pulmonary rehabilitation (PR). METHODS:At pre-PR assessment, study participants completed a 2MWT twice in addition to usual measures (6MWT and Chronic Respiratory Questionnaire). At post-PR assessment following a standard PR program, measures were repeated and global rating of change scores obtained (patient and therapist). Pre-post program change scores were examined for correlations with change in 2-minute walk distance (2MWD) and used (where r?0.3) to estimate the MID through anchor-based methods. Distribution-based estimates based on standard error of measurement were examined. Test-retest reliability (intraclass correlation coefficient [ICC] and Bland-Altman agreement) and validity (Pearson correlation with 6-minute walk distance [6MWD]) were reported. RESULTS:Fifty-nine people (28 men) with stable COPD, mean age 68 years (SD 10 years), and percentage predicted forced expiratory volume in 1 second 48% (SD 20%) attended pre-PR assessment. Test-retest ICC for same-session 2MWD was 0.985. A mean difference of 2.4 m (95% confidence interval [CI] 0.7-4.0 m, P=0.006) occurred between the first and second trials. 2MWD and 6MWD were highly correlated (r=0.87, P<0.001). Forty-one participants completed PR and were included in responsiveness and MID analysis. Mean 2MWD improved significantly post-PR (8.8 m, 95% CI 3.6-14 m, P=0.001). The MID in 2MWD, anchored against clinically meaningful change in 6MWD, was 5.5 m (area under curve =0.81, P=0.001). Distribution-based methods estimated an MID of 4 m. CONCLUSION:Change in 2MWD of at least 5.5 m following a PR program corresponded to a clinically meaningful change. A practice test is recommended due to learning effects.

SUBMITTER: Johnston KN

PROVIDER: S-EPMC5640407 | biostudies-literature | 2017

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Minimal important difference and responsiveness of 2-minute walk test performance in people with COPD undergoing pulmonary rehabilitation.

Johnston Kylie Nicole KN Potter Adrian James AJ Phillips Anna Caroline AC

International journal of chronic obstructive pulmonary disease 20171009

<h4>Background and objectives</h4>Field exercise tests (eg, 6-minute walk test [6MWT]) are important measures of functional exercise capacity in people with COPD. Shorter tests such as the 2-minute walk test (2MWT) may offer advantages in some populations but lack information about responsiveness to change. This study examined responsiveness, minimal important difference (MID), test-retest reliability, and construct validity of the 2MWT in people with stable COPD attending outpatient pulmonary r ...[more]

PMID: 29070945

Similar Datasets

Project description:Morquio A syndrome is an ultra-rare, inherited lysosomal storage disorder associated with progressive, multi-systemic clinical impairments, causing gradual loss of functional capacity and endurance, impaired quality of life, and early mortality. Studies in Morquio A patients have used the 6-min walk test (6MWT) to assess functionality and endurance and to evaluate disease progression or efficacy of treatment. The objective of the present study was to review minimal clinically important differences (MCIDs) for the 6MWT reported for disease states that widely use the 6MWT to evaluate clinical benefit and to discuss the results in view of the challenges in estimating MCID for ultra-rare diseases, using the case of elosulfase alfa in Morquio A patients. A systematic literature search was performed using Embase and Medline to identify studies specifically estimating the MCID using either anchor-based or distribution-based methods. A total of 19 publications on 17 studies were identified; none of these included patients with Morquio A syndrome or the wider disease category of lysosomal storage disorders. Therefore, the MCIDs determined by studies in patients with respiratory, cardiovascular, or musculoskeletal disease were compared to changes in the 6MWT seen in Morquio A patients in the pivotal phase 3 clinical trial of elosulfase alfa enzyme replacement therapy. The literature review showed a mean MCID for the 6MWT of 7% change (range 3-15%) in studies using anchor-based methods and a 9% change (range 4-16%) using distribution-based methods. Results of the elosulfase alfa clinical trial and its extension showed a placebo-adjusted 14.9% improvement in the 6MWT from baseline at week 24, which was greater than the mean MCID based on the results of the systematic literature review. After 2 years, 6MWT distance increased by a mean of 20.7% from baseline in a modified per-protocol population, versus a reduction of 6.9% in comparable untreated patients from the MorCAP natural history study over the same period. Although further research is required to establish the MCID of the 6MWT in Morquio A patients, the presented data provide further evidence for the positive effect of elosulfase alfa in this patient population.

Project description:BackgroundThe Multiple Sclerosis Questionnaire for Physical Therapists (MSQPT) is a patient-rated outcome questionnaire for evaluating the rehabilitation of persons with multiple sclerosis (MS). Responsiveness was evaluated, and minimal important difference (MID) estimates were calculated to provide thresholds for clinical change for four items, three sections and the total score of the MSQPT.MethodsThis multicentre study used a combined distribution- and anchor-based approach with multiple anchors and multiple rating of change questions. Responsiveness was evaluated using effect size, standardized response mean (SRM), modified SRM and relative efficiency. For distribution-based MID estimates, 0.2 and 0.33 standard deviations (SD), standard error of measurement (SEM) and minimal detectable change were used. Triangulation of anchor- and distribution-based MID estimates provided a range of MID values for each of the four items, the three sections and the total score of the MSQPT. The MID values were tested for their sensitivity and specificity for amelioration and deterioration for each of the four items, the three sections and the total score of the MSQPT. The MID values of each item and section and of the total score with the best sensitivity and specificity were selected as thresholds for clinical change. The outcome measures were the MSQPT, Hamburg Quality of Life Questionnaire for Multiple Sclerosis (HAQUAMS), rating of change questionnaires, Expanded Disability Status Scale, 6-metre timed walking test, Berg Balance Scale and 6-minute walking test.ResultsThe effect size ranged from 0.46 to 1.49. The SRM data showed comparable results. The modified SRM ranged from 0.00 to 0.60. Anchor-based MID estimates were very low and were comparable with SD- and SEM-based estimates. The MSQPT was more responsive than the HAQUAMS in detecting improvement but less responsive in finding deterioration. The best MID estimates of the items, sections and total score, expressed in percentage of their maximum score, were between 5.4% (activity) and 22% (item 10) change for improvement and between 5.7% (total score) and 22% (item 10) change for deterioration.ConclusionsThe MSQPT is a responsive questionnaire with an adequate MID that may be used as threshold for change during rehabilitation of MS patients.Trial registrationThis trial was retrospectively (01/24/2015) registered in ClinicalTrials.gov as NCT02346279.

Project description:BackgroundThe 6-minute walk test (6MWT) is a commonly used metric for measuring change in mobility after knee arthroplasty, however, what is considered an improvement after surgery has not been defined. The determination of important change in an outcome assessment tool is controversial and may require more than one approach. This study, nested within a combined randomised and observational trial, aimed to define a minimal important improvement threshold for the 6MWT in a knee arthroplasty cohort through a triangulation of methods including patient-perceived anchor-based thresholds and distribution-based thresholds.MethodsIndividuals with osteoarthritis performed a 6MWT pre-arthroplasty then at 10 and 26 weeks post-surgery. Each rated their perceived improvement in mobility post-surgery on a 7-point transition scale anchored from "much better" to "much worse". Based on these responses the cohort was dichotomised into 'improved' and 'not improved'. The thresholds for patient-perceived improvements were then identified using two receiver operating curve methods producing sensitivity and specificity indices. Distribution-based change thresholds were determined using two methods utilising effect size (ES). Agreement between the anchor- and distribution-based methods was assessed using kappa.ResultsOne hundred fifty-eight from 166 participants in the randomised cohort and 222 from 243 in the combined randomised and observational cohort were included at 10 and 26 weeks, respectively. The slightly or more patient-perceived improvement threshold at 26 weeks (an absolute improvement of 26 m) was the only one to demonstrate sensitivity and specificity results both better than chance. At 10- and 26-weeks, the ES based on the mean change score divided by the baseline standard deviation (SD), was an absolute change of 24.5 and 37.9 m, respectively. The threshold based on a moderate ES (a 0.5 SD of the baseline score) was a change of 55.0 and 55.4 m at 10- and 26-weeks, respectively. The level of agreement between the 26-week anchor-based and distribution-based minimal absolute changes was very good (k = 0.88 (95 % CI 0.81 0.95)).ConclusionA valid threshold of improvement for the 6MWT can only be proposed for changes identified from baseline to 26 weeks post-surgery. The level of agreement between anchor- and distribution-based methods indicates that a true minimal or more threshold of meaningful improvement following surgery is likely within the ranges proposed by the triangulation of all four methods, that is, 26 to 55 m.

Dataset Information

Minimal important difference and responsiveness of 2-minute walk test performance in people with COPD undergoing pulmonary rehabilitation.

Publications

Minimal important difference and responsiveness of 2-minute walk test performance in people with COPD undergoing pulmonary rehabilitation.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets