L. Jasper1, L. Beaupre1, J.C. Spence2, C.A. Jones1
1University of Alberta, Department of Physical Therapy, Edmonton, Canada, 2University of Alberta, Faculty of Kinesiology, Sport, and Recreation, Edmonton, Canada
Background: In spite of improvements in pain and function following total knee arthroplasty (TKA), older adults often do not increase their levels of physical activity post-surgery to sufficient levels to avoid the negative health effects of physical inactivity. It is necessary to have valid tools to measure physical activity in this population to address physical inactivity and maximize health.
Purpose: To examine the validity of two clinical measures – a personal activity tracker (Fitbit) and a self-report measure (CHAMPS) as compared to a reference standard accelerometer (the SenseWear armband or SWA) – to determine appropriate tools for clinical use.
Methods: At six months post-TKA, 47 older adults wore the Fitbit and SWA for five days and then completed the CHAMPS questionnaire. Physical activity data from the two clinical tools were compared to data from the SWA through statistical analyses including intraclass correlation coefficients (ICC), Pearson’s correlation coefficients, equivalence testing and Bland Altman plots.
Results: Moderate to good correlation was found between the Fitbit and SWA for steps (ICC=0.79), energy expenditures (ICC=0.78) and energy expenditures < 3 METS (ICC=0.79). Poor to moderate correlations were found when measuring time spent in specific activity intensities (ICCs=0.41 to 0.56) and between the CHAMPS and SWA in the measurement of energy expenditure (ICC=0.43).
Conclusion(s): The Fitbit may be a reasonable tool to measure steps and energy expenditure in older adults following TKA. The CHAMPS may be an appropriate self-report measure to use when high accuracy is not required.
Implications: These findings will provide guidance regarding the choice of clinical tool to measure physical activity in older adults post-TKA. Obtaining accurate information on the levels of physical activity is essential to ensure these older adults are achieving sufficient levels of physical activity to avoid the detrimental effects on health due to inactivity.
Funding, acknowledgements: This study was supported by an Innovation Grant from the Covenant Health Network of Excellence in Seniors’ Health and Wellness.
Keywords: Accelerometer, steps, energy expenditure
Topic: Health promotion & wellbeing/healthy ageing/physical activity
Did this work require ethics approval? Yes
Institution: University of Alberta
Committee: University of Alberta Research Ethics Board
Ethics number: Pro00062054
All authors, affiliations and abstracts have been published as submitted.
