Self-reported Sitting Time is Associated With Decreased Mobility in Older Adults.

BACKGROUND AND PURPOSE: Prolonged sitting is associated with increased risk of sarcopenia in community-dwelling older adults and can lead to poor muscle function, limited balance and transfer abilities, and mobility limitations. Sitting time can be a modifiable factor in preserving independent mobility in older adults. Assessing sitting time is an important measure for preventive medicine in older populations. The purposes of this study were to examine the test-retest reliability of older adults' reported (using a recall strategy) sitting time and to determine its association with mobility limitation.

METHODS: In this cross-sectional study, 140 older adults aged 65 years or more from community centers were assessed for their sitting time and mobility limitation. A week later, 86 participants returned for the retest of sitting time. The test-retest reliability of the reported (recall strategy) measure of sitting time was examined by intraclass correlation coefficient (ICC), and its association with mobility limitation was examined by logistic regression analysis adjusted for age.

RESULTS: The reported measure (recall strategy) of sitting time showed good test-retest reliability (ICC = 0.85). The results of logistic regression analysis indicated that sitting time was associated with mobility limitation, adjusted for age.

DISCUSSION: Older adults' reported (recall strategy) sitting time had good test-retest reliability (ICC(2,1) = 0.85). The reported measure (recall strategy) seems to have yielded consistent reporting. The association of prolonged sitting time with mobility limitation needs to be substantiated in a future longitudinal study to determine whether a causality relationship exists.

CONCLUSIONS: Sitting time in older adults can be reliably measured with a reported measure (a recall strategy) over a 1-week interval. Older adults who spend more time sitting are more likely to experience mobility limitation.