TY - JOUR T1 - Minimal clinically important difference for daily pedometer step count in COPD JF - ERJ Open Research JO - erjor DO - 10.1183/23120541.00823-2020 VL - 7 IS - 1 SP - 00823-2020 AU - Oliver Polgar AU - Suhani Patel AU - Jessica A. Walsh AU - Ruth E. Barker AU - Stuart F. Clarke AU - William D-C. Man AU - Claire M. Nolan Y1 - 2021/01/01 UR - http://openres.ersjournals.com/content/7/1/00823-2020.abstract N2 - Assessment of physical activity is an important part of COPD management, because physical inactivity is associated with mortality and morbidity in this disease group [1]. The most commonly used physical activity outcome is daily step count, typically measured using an accelerometer or pedometer [2]. Outside the research arena, pedometers are used more commonly than accelerometers due to lower cost, simplicity and acceptability to patients. Although previous studies have described the minimal clinically important difference (MCID) in accelerometer daily step count, these estimates are not appropriate for the interpretation of meaningful changes in pedometer step count, as pedometers are less reliable in capturing daily step count [3]. The MCID for improvement in daily pedometer step count in patients with COPD undergoing pulmonary rehabilitation is not known, and there are limited data on MCID for deterioration in pedometer step count. The aim of our study was to provide an estimate of the MCID for daily pedometer step count in patients with COPD, using response to pulmonary rehabilitation as a model of improvement and longitudinal decline following pulmonary rehabilitation as a model of deterioration.Pedometer step count improves with pulmonary rehabilitation and deteriorates with time. The MCID for improvement and deterioration is 427 and −456 steps, respectively, but there is uncertainty about the reliability of these estimates. https://bit.ly/3ci97JhWe would like to express our gratitude to the patients for participating in this study. We would also like to thank the staff of the Harefield Pulmonary Rehabilitation Unit for their help with data collection. ER -