Mélany Hars1, François R Herrmann, Andrea Trombetti. 1. Division of Bone Diseases, Geneva University Hospitals and Faculty of Medicine, Geneva, Switzerland. Electronic address: melany.hars@hcuge.ch.
Abstract
PURPOSE: Gait variables may constitute surrogate outcomes for fall risk. Their reliability in a specific population of older fallers has not been fully established, which limits their research and clinical applications. This study aimed to determine test-retest reliability and minimal detectable change (MDC) values for selected fall-related gait variables in older adults with a recent fall history. METHODS: Community-dwelling (n=30) and hospitalized (n=30) fallers aged≥65 years were assessed twice using an instrumented pressure-sensitive walkway, under single- and dual-task gait conditions. Intraclass correlation coefficient (ICC(2,1)), standard error of measurement (SEM; SEM%) and MDC at 95% confidence level (MDC95; MDC95%), were used as reliability estimates. RESULTS: The ICC(2,1) for gait velocity was greater than 0.84 across all gait conditions and groups; SEM% and MDC95% did not exceed 6.5% and 18.1%, respectively. Gait variability measures returned lower ICC(2,1) (range 0.18-0.79), and markedly higher SEM% (16.3-31.9%) and MDC95% (45.3-88.3%). Overall, hospitalized fallers exhibited larger SEM and MDC95 values for variability measures compared to community-dwellers in all gait conditions, while larger values were found for all variables while dual-tasking compared to single-tasking in both groups. CONCLUSIONS: Gait velocity was found to be highly reliable and likely to be sensitive to change over repeated sessions in community-dwelling and hospitalized older fallers, both under single- and dual-task conditions. Gait variability measures showed lower reliability, irrespective of gait condition or group, displaying consistently larger measurement error, particularly under dual-task conditions. Clinicians should consider MDC95 values before using gait variability variables as evaluative outcome measures at patient level.
PURPOSE: Gait variables may constitute surrogate outcomes for fall risk. Their reliability in a specific population of older fallers has not been fully established, which limits their research and clinical applications. This study aimed to determine test-retest reliability and minimal detectable change (MDC) values for selected fall-related gait variables in older adults with a recent fall history. METHODS: Community-dwelling (n=30) and hospitalized (n=30) fallers aged≥65 years were assessed twice using an instrumented pressure-sensitive walkway, under single- and dual-task gait conditions. Intraclass correlation coefficient (ICC(2,1)), standard error of measurement (SEM; SEM%) and MDC at 95% confidence level (MDC95; MDC95%), were used as reliability estimates. RESULTS: The ICC(2,1) for gait velocity was greater than 0.84 across all gait conditions and groups; SEM% and MDC95% did not exceed 6.5% and 18.1%, respectively. Gait variability measures returned lower ICC(2,1) (range 0.18-0.79), and markedly higher SEM% (16.3-31.9%) and MDC95% (45.3-88.3%). Overall, hospitalized fallers exhibited larger SEM and MDC95 values for variability measures compared to community-dwellers in all gait conditions, while larger values were found for all variables while dual-tasking compared to single-tasking in both groups. CONCLUSIONS: Gait velocity was found to be highly reliable and likely to be sensitive to change over repeated sessions in community-dwelling and hospitalized older fallers, both under single- and dual-task conditions. Gait variability measures showed lower reliability, irrespective of gait condition or group, displaying consistently larger measurement error, particularly under dual-task conditions. Clinicians should consider MDC95 values before using gait variability variables as evaluative outcome measures at patient level.
Authors: Mélany Hars; François R Herrmann; Roger A Fielding; Kieran F Reid; René Rizzoli; Andrea Trombetti Journal: Calcif Tissue Int Date: 2014-08-23 Impact factor: 4.333
Authors: Maha Almarwani; Subashan Perera; Jessie M VanSwearingen; Patrick J Sparto; Jennifer S Brach Journal: Gait Posture Date: 2015-11-30 Impact factor: 2.840