Article

Few instruments that measure physical activity (PA) can accurately
quantify PA performed at light and moderate intensities, which is particularly
relevant in older adults.
The evidence of their reliability in free-living
conditions is limited. OBJECTIVE: The study objectives were:
(1) to determine the
test-retest reliability of the Actigraph (ACT), SenseWear Armband (SWA), and
Community Healthy Activities Model Program for Seniors (CHAMPS) questionnaire in
assessing free-living PA at light and moderate intensities in people after total
knee arthroplasty; (2) to compare the reliability of the 3 instruments relative
to each other; and (3) to determine the reliability of commonly used monitoring
time frames (24 hours, waking hours, and 10 hours from awakening). DESIGN: A
one-group, repeated-measures design was used. METHODS: Participants wore the
activity monitors for 2 weeks, and the CHAMPS questionnaire was completed at the
end of each week. Test-retest reliability was determined by using the intraclass
correlation coefficient (ICC [2,k]) to compare PA measures from one week with
those from the other week. RESULTS: Data from 28 participants who reported
similar PA during the 2 weeks were included in the analysis. The mean age of
these participants was 69 years (SD=8), and 75% of them were women. Reliability
ranged from moderate to excellent for the ACT (ICC=.75-.86) and was excellent for
the SWA (ICC=.93-.95) and the CHAMPS questionnaire (ICC=.86-.92). The 95%
confidence intervals (95% CI) of the ICCs from the SWA were the only ones within
the excellent reliability range (.85-.98). The CHAMPS questionnaire showed
systematic bias, with less PA being reported in week 2. The reliability of PA
measures in the waking-hour time frame was comparable to that in the 24-hour time
frame and reflected most PA performed during this period. LIMITATIONS:
Reliability may be lower for time intervals longer than 1 week. CONCLUSIONS: All
PA measures showed good reliability. The reliability of the ACT was lower than
those of the SWA and the CHAMPS questionnaire. The SWA provided more precise
reliability estimates. Wearing PA monitors during waking hours provided
sufficiently reliable measures and can reduce the burden on people wearing them.
CI - (c) 2016 American Physical Therapy Association.

Langue : ANGLAIS