RT Journal Article SR Electronic T1 Minimal clinically important difference for daily pedometer step count in COPD JF ERJ Open Research JO erjor FD European Respiratory Society SP 00823-2020 DO 10.1183/23120541.00823-2020 VO 7 IS 1 A1 Oliver Polgar A1 Suhani Patel A1 Jessica A. Walsh A1 Ruth E. Barker A1 Stuart F. Clarke A1 William D-C. Man A1 Claire M. Nolan YR 2021 UL http://openres.ersjournals.com/content/7/1/00823-2020.abstract AB