Evaluating the discriminatory power of the velocity field diagram and timed-up-and-go test in determining the fall status of community-dwelling older adults: a cross-sectional observational study

• Published in: BMC geriatrics 2022-08, Vol.22 (1), p.658-19, Article 658
• Main Authors: Ibeneme, Sam Chidi, Eze, Joy Chinyere, Okonkwo, Uchenna Prosper, Ibeneme, Georgian Chiaka, Fortwengel, Gerhard
• Format: Article
• Language: English
• Subjects: Ability tests; Accidental Falls - prevention & control; Activities of daily living; Aged; Arthritis; Balance; Biomechanics; Classification; Community-dwelling older adults; Cross-Sectional Studies; Diabetes; Discriminatory power; Falls; Gait; Geriatric Assessment - methods; Geriatrics; Health facilities; Humans; Independent Living; Injuries; Observational studies; Older people; Postural Balance; Prevention; Reproducibility of Results; Time and Motion Studies; Timed-up-and-go test; Validity; Velocity; Velocity field diagram; Walking
• ISSN: 1471-2318; 1471-2318
• DOI: 10.1186/s12877-022-03282-2

Systematic reviews demonstrated that gait variables are the most reliable predictors of future falls, yet are rarely included in fall screening tools. Thus, most tools have higher specificity than sensitivity, hence may be misleading/detrimental to care. Therefore, this study aimed to determine the validity, and reliability of the velocity field diagram (VFD -a gait analytical tool), and the Timed-up-and-go test (TUG)-commonly used in Nigeria as fall screening tools, compared to a gold standard (known fallers) among community-dwelling older adults. This is a cross-sectional observational study of 500 older adults (280 fallers and 220 non-fallers), recruited by convenience sampling technique at community health fora on fall prevention. Participants completed a 7-m distance with the number of steps and time it took determined and used to compute the stride length, stride frequency, and velocity, which regression lines formed the VFD. TUG test was simultaneously conducted to discriminate fallers from non-fallers. The cut-off points for falls were: TUG times ≥ 13.5 s; VFD's intersection point of the stride frequency, and velocity regression lines (E ) ≥ 3.5velots. The receiver operating characteristic (ROC) area under the curves (AUC) was used to explore the ability of the E  ≥ 3.5velots to discriminate between fallers and non-fallers. The VFD's and TUG's sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) were determined. Alpha was set at p