Research Study Abstract

Agreement of classification of COPD patients’ physical activity with two activity monitors

  • Presented on Sept. 8, 2013

Rationale It is unclear whether different activity monitors provide similar classification of physical activity (PA) in patients with COPD.

Aim To test whether similar PA classification of patients would be obtained when using 2 valid activity monitors.

Methods We 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.

Results ACT 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  0.76 95%CI 0.75-0.77]. For VMU these values were 76% [weighted  0.69 95%CI 0.68-0.70].. Changes from week 1 to 4 were also tracked similarly by both monitors.

Conclusions The 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.


  • Heleen Demeyer 1
  • Roberto Rabinovich 2
  • Susan Loh 2
  • Yogini Raste 3
  • Nick Hopkinson 3
  • Zafi ris Louvaris 4
  • Iannis Vogiatzis 4
  • Corina De Jong 5
  • Tys Van der Molen 6
  • Elena Gimeno-Santos 7
  • Solange Rohou 8
  • Damijan Erzen 10
  • Karoly Kulich 9
  • Niklas Karlsson 8
  • Thierry Troosters 1
  • Judith Garcia Aymerich 7


  • 1

    Department of Rehabilitation Sciences, KULeuven, Leuven, Belgium

  • 2

    ELEGI/Colt Laboratory, UoE/MRC Centre for Infl ammation Research, The University of Edinburgh, Edinburgh, Scotland, United Kingdom

  • 3

    NIHR Respiratory Biomedical Research Unit of the Royal Brompton and Harefield NHS Lung Institute, Imperial College London, London, United Kingdom

  • 4

    Department of Critical Care Medicine, Pulmonary Rehabilitation Centre, Evangelismos Hospital, National Kapodistrian University of Athens, M’ Simou and GP Livanos Laboratories, Thorax Foundation, Athens, Greece

  • 5

    Department of General Practice, University Medical Center Groningen, Groningen, Netherlands

  • 6

    Department of Primary Care, University of Groningen, UMCG, Groningen, Netherlands

  • 7

    Centre for Research in Environmental Epidemiology, CREAL, Barcelona, Spain

  • 8

    R&D, Astra Zeneca, Mölndal, Sweden

  • 9

    Respiratory, Novartis, Basel, Switzerland

  • 10

    10Respiratory Diseases Research, Boehringer-Ingelheim, Ingelheim, Germany

Presented at

ERS Annual Congress 2013


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