%0 Journal Article %A Heleen Demeyer %A Roberto Rabinovich %A Susan Loh %A Yogini Raste %A Nick Hopkinson %A Zafiris Louvaris %A Iannis Vogiatzis %A Corina De Jong %A Tys Van der Molen %A Elena Gimeno-Santos %A Solange Rohou %A Damijan Erzen %A Karoly Kulich %A Niklas Karlsson %A Thierry Troosters %A Judith Garcia Aymerich %T Agreement of classification of COPD patients' physical activity with two activity monitors %D 2013 %J European Respiratory Journal %P 1478 %V 42 %N Suppl 57 %X RationaleIt is unclear whether different activity monitors provide similar classification of physical activity (PA) in patients with COPD.AimTo test whether similar PA classification of patients would be obtained when using 2 valid activity monitors.MethodsWe assessed PA for 4 weeks with Actigraph [(ACT: Steps and vector magnitude units (VMU)] and Dynaport [DAM: Steps, Movement intensity (MI), VMU] activity monitor in 236 COPD patients (FEV1 57±20%pred; 6MWD 430±125m) from 5 European centers resulting in 6776 patient-days.ResultsACT and DAM had respectively 11% and 6% missing patient-days and 11% and 12% patient-days had less than 8h of assessment. Steps per day recorded on ACT (mean±SD: 4248±2740) were lower than DAM (4767±2859, p<0.001). Similar concepts from DAM and ACT correlated very highly (R=0.91 VMU to 0.93 Steps). PA levels were converted to deciles in order to verify whether patients would also be classified in similar activity deciles with both monitors. For steps, 85% of patient-days were classified within 1 decile difference with both monitors [weighted κ 0.76 95%CI 0.75-0.77]. For VMU these values were 76% [weighted κ 0.69 95%CI 0.68-0.70]. Changes from week 1 to 4 were also tracked similarly by both monitors.ConclusionsThe PA values recorded on both monitors differed by a small, but statistically significant amount. Classification of patients in deciles renders very similar results with both ACT and DAM. %U https://erj.ersjournals.com/content/erj/42/Suppl_57/1478.full.pdf