title: Study to determine the criterion validity of the SenseWear Armband as a measure of physical activity in people with rheumatoid arthritis.
abstract: OBJECTIVE
  Measuring physical activity in people with rheumatoid arthritis (RA) is of great importance in light of the increased mortality in this population due to cardiovascular disease. Validation of activity monitors in specific populations is recommended to ensure the accuracy of physical activity measurement. Thus, the purpose of this study was to determine the validity of the SenseWear Pro3 Armband (SWA) as a measure of physical activity during activities of daily living (ADL) in people with RA.
  
  
  METHODS
  Fourteen subjects (8 men and 6 women) with a diagnosis of RA were recruited from rheumatology clinics at the Mid-Western Regional Hospitals, Limerick, Ireland. Participants undertook a series of ADL of varying intensities. The SWA was compared to the criterion measures of the Oxycon Mobile indirect calorimetry system (energy expenditure in kJ) and of manual video observation (step count). Bland and Altman, intraclass correlation coefficient (ICC), and correlation analyses were done using SPSS, version 19.0.
  
  
  RESULTS
  The SWA showed substantial agreement (ICC 0.717, P < 0.001) and a strong relationship (Pearson's correlation coefficient = 0.852) compared with the criterion measure when estimating energy expenditure during ADL. However, it was found that the SWA overestimated energy expenditure, particularly at higher intensity levels. The ability of the SWA to estimate step counts during ADL was poor (ICC 0.304, P = 0.038).
  
  
  CONCLUSIONS
  The SWA can be considered a valid tool to estimate energy expenditure during ADL in the RA population; however, attention should be paid to its tendency to overestimate energy expenditure.
authors.affiliation: Department of Clinical Therapies, University of Limerick, Limerick, Ireland. marie.tierney@ul.ie
authors.forename: Marie
authors.initials: M
authors.lastname: Tierney
authors.forename: Alexander
authors.initials: A
authors.lastname: Fraser
authors.forename: Helen
authors.initials: H
authors.lastname: Purtill
authors.forename: Norelee
authors.initials: N
authors.lastname: Kennedy
mesh_terms: D000203:Activities of Daily Living; D000368:Aged; D001172:Arthritis, Rheumatoid / Q000503:physiopathology*; D002153:Calorimetry, Indirect; D004734:Energy Metabolism / Q000502:physiology; D005260:Female; D006801:Humans; D007494:Ireland; D008297:Male; D008875:Middle Aged; D008991:Monitoring, Physiologic / Q000295:instrumentation*; D009043:Motor Activity / Q000502:physiology*; D015203:Reproducibility of Results