Between-day repeatability of sensor-based in-home gait assessment among older adults: assessing the effect of frailty

Danya Pradeep Kumar, Christopher Wendel, Jane Mohler, Kaveh Laksari, Nima Toosizadeh

Research output: Contribution to journalArticlepeer-review

3 Scopus citations


Background: While sensor-based daily physical activity (DPA) gait assessment has been demonstrated to be an effective measure of physical frailty and fall-risk, the repeatability of DPA gait parameters between different days of measurement is not clear. Aims: To evaluate test–retest reliability (repeatability) of DPA gait performance parameters, representing the quality of walking, and quantitative gait measures (e.g. number of steps) between two separate days of assessment among older adults. Methods: DPA was acquired for 48-h from older adults (age ≥ 65 years) using a tri-axial accelerometer. Continuous walking bouts (≥ 60 s) were identified from acceleration data and used to extract gait performance parameters, including time- and frequency-domain gait parameters, representing walking speed, variability, and irregularity. To assess repeatability, intraclass correlation coefficient (ICC) was calculated using two-way mixed effects F-test models for day-1 vs. day-2 as the independent random effect. Repeatability tests were performed for all participants and also within frailty groups (non-frail and pre-frail/frail identified using Fried phenotype). Results: Data was analyzed from 63 older adults (29 non-frail and 34 pre-frail/frail). Most of the time- and frequency-domain gait performance parameters showed good to excellent repeatability (ICC ≥ 0.70), while quantitative parameters, including number of steps and walking duration showed poor repeatability (ICC < 0.30). Among majority of the gait performance parameters, we observed higher repeatability among the pre-frail/frail group (ICC > 0.78) compared to non-frail individuals (0.39 < ICC < 0.55). Conclusion: Gait performance parameters, showed higher repeatability compared to quantitative measures. Higher repeatability among pre-frail/frail individuals may be attributed to a reduced functional capacity for performing more intense and variable physical tasks. Trial registration: The clinical trial was retrospectively registered on June 18th, 2013 with, identifier NCT01880229.

Original languageEnglish (US)
Pages (from-to)1529-1537
Number of pages9
JournalAging Clinical and Experimental Research
Issue number6
StatePublished - Jun 2021


  • Continuous walking
  • Daily physical activity
  • Frailty
  • Gait performance parameters
  • Repeatability

ASJC Scopus subject areas

  • Aging
  • Geriatrics and Gerontology


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