Validity of six activity monitors in chronic obstructive pulmonary disease: a comparison with indirect calorimetry

Hans Van Remoortel, Yogini Raste, Zafeiris Louvaris, Santiago Giavedoni, Chris Burtin, Daniel Langer, Frederick Wilson, Roberto Rabinovich, I Vogiatzis, Nicholas S. Hopkinson, Thierry Troosters

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183 Citations (Scopus)

Abstract

Reduced physical activity is an important feature of Chronic Obstructive Pulmonary Disease (COPD). Various activity monitors are available but their validity is poorly established. The aim was to evaluate the validity of six monitors in patients with COPD. We hypothesized triaxial monitors to be more valid compared to uniaxial monitors. Thirty-nine patients (age 68 +/- 7years, FEV1 54 +/- 18%predicted) performed a one-hour standardized activity protocol. Patients wore 6 monitors (Kenz Lifecorder (Kenz), Actiwatch, RT3, Actigraph GT3X (Actigraph), Dynaport MiniMod (MiniMod), and SenseWear Armband (SenseWear)) as well as a portable metabolic system (Oxycon Mobile). Validity was evaluated by correlation analysis between indirect calorimetry (VO2) and the monitor outputs: Metabolic Equivalent of Task [METs] (SenseWear, MiniMod), activity counts (Actiwatch), vector magnitude units (Actigraph, RT3) and arbitrary units (Kenz) over the whole protocol and slow versus fast walking. Minute-by-minute correlations were highest for the MiniMod (r = 0.82), Actigraph (r = 0.79), SenseWear (r = 0.73) and RT3 (r = 0.73). Over the whole protocol, the mean correlations were best for the SenseWear (r = 0.76), Kenz (r = 0.52), Actigraph (r = 0.49) and MiniMod (r = 0.45). The MiniMod (r = 0.94) and Actigraph (r = 0.88) performed better in detecting different walking speeds. The Dynaport MiniMod, Actigraph GT3X and SenseWear Armband (all triaxial monitors) are the most valid monitors during standardized physical activities. The Dynaport MiniMod and Actigraph GT3X discriminate best between different walking speeds.
Original languageEnglish
Article number0039198
JournalPLoS ONE
Volume7
Issue number6
DOIs
Publication statusPublished - 20 Jun 2012
Externally publishedYes

Cite this

Van Remoortel, H., Raste, Y., Louvaris, Z., Giavedoni, S., Burtin, C., Langer, D., Wilson, F., Rabinovich, R., Vogiatzis, I., Hopkinson, N. S., & Troosters, T. (2012). Validity of six activity monitors in chronic obstructive pulmonary disease: a comparison with indirect calorimetry. PLoS ONE, 7(6), [0039198]. https://doi.org/10.1371/journal.pone.0039198