Intrarater and Interrater Reliability and Concurrent Validity of the 3-Meter Backward Walk Test in Non-frail, Pre-frail, and Frail Older Adults in Residential Care Homes

Abstract

Importance Assessing backward walking ability in older adults is crucial due to its strong association with balance, mobility, and fall risk. The 3-meter backward walk test (3MBWT) provides a quick and valid tool for this purpose. Objective The objective of this study was to assess the reliability and validity of the 3MBWT and to determine its effectiveness in differentiating between different levels of frailty. Design This study used a cross-section design. Setting The study was carried out in residential care homes for older adults. Participants Participants were able to walk with or without assistance and were excluded if they had a Mini-Mental State Examination score ≤ 17. Interventions Participants underwent the 3MBWT and the 10-meter walk test (10MWT). In addition, the Short Physical Performance Battery (SPPB) was administered. Main Outcome(s) and Measure(s) Frailty was assessed using the SHARE-FI instrument, with participants classified as non-frail, pre-frail, or frail. Reliability of the 3MBWT was assessed using intraclass correlation coefficient (ICC [3,1]), and concurrent validity was assessed using the 10MWT and SPPB. Fall history over the past year was obtained from medical records and participant interviews. Results Participants (n = 217) were categorized as non-frail (27%), pre-frail (31%), or frail (42%). The average 3MBWT times were 5.0, 5.9, and 11.8 seconds for participants who were non-frail, pre-frail, and frail, respectively. The 3MBWT showed good to excellent intrarater reliability (ICC = 0.89-0.93) and excellent interrater reliability (ICC = 0.90-0.99). It showed strong correlations with the 10MWT (r = 0.91) and SPPB walking speed (r = 0.94), and a negative correlation with the SPPB total score (r =-0.86). Moderate correlations were found with the Falls Efficacy Scale International (r = 0.71) and Multidimensional Fatigue Inventory (r = 0.61), and a high correlation with falls in the last 12 months (r = 0.74). Conclusions The 3MBWT is a reliable tool for assessing physical performance and differentiating levels of frailty in older adults, with a strong association with fall history. Relevance The 3MBWT offers clinicians a quick, simple, and valid tool for assessing older adults in residential care.