LAUSR

Background: Previous research has calculated the minimal important difference (MID) for the 1-minute sit-to-stand test (1-STST) in patients with COPD to be three repetitions and stated that the 1-STST could be an alternative to the traditional 6-minute walk test (6MWT) to measure exercise performance. Objective: The aim of our study was to prospectively estimate the MID for the 1-STST in response to a 3-week inpatient pulmonary rehabilitation program (PR) in patients with advanced COPD. Methods: 95 patients with COPD (66±8years; FEV1: 37±12%/pred.;1-STST: 19.3±6.9reps) were included in this observational study (NCT02708719). At PR-start and PR-end patients performed a 1-STST on a force platform. Patients also performed two 6MWTs and filled out the chronic respiratory questionnaire (CRQ) for performing an anchor based method. Additionally, difference distribution based methods were used to estimate the MID. Results: An anchor based method could not be used due to the lack of properly associated anchors. Neither the change in 6MWD, nor the changes in the CRQ scores correlated well with the change in 1-STST (all r Conclusion: Results from this study estimated the MID for the 1-STST after PR to be between 2.03 and 3.45 repetitions in this specific population. However, since the change in 1-STST only correlated weakly with the change in 6MWD (r=0.21) it can be assumed that the 1-STST and the 6MWT may measure different qualities of exercise performance.