A new valid Walking Aid Scale better predicts distance walked by prosthesis users than Prosthetic Mobility Questionnaire 2.0 and Activities-Specific Balance Confidence Scale

Abstract

The availability of psychometrically-sound and parsimonious outcome measures is key for optimizing decision-making about prosthetic fitting and rehabilitation in lower limb prosthesis users. Despite the increasing clinical use of observational and self-reported scales for assessing mobility and balance, there is currently no scale that accounts for the use of assistive devices while walking under conditions of increasing difficulty. Therefore, the purpose of this study was to develop and validate a Walking Aid Scale (WAS) in a cross-sectional sample of 144 prosthesis users. Specifically, we examined internal consistency and concurrent validity of WAS against two commonly used self-report measures of prosthetic mobility and balance confidence – the Prosthetic Mobility Questionnaire 2.0 (PMQ 2.0) and Activities-Specific Balance Confidence Scale (ABC-5). The predictive value of WAS, in comparison to PMQ 2.0 and ABC-5, was assessed using a 6-Minute Walk Test (6MWT) and participants’ characteristics. The WAS showed significant moderate-to-good correlations with PMQ 2.0 and ABC-5, and all scales correlated well with age and 6MWT. Participants who relied less on walking aids reported higher mobility levels, greater balance confidence, and walked longer distances. Age was associated with greater use of walking aids and lower mobility and balance confidence. In the stepwise linear regression analysis, age, amputation level, time since amputation, and WAS predicted about two-thirds of the variability in 6MWT with no significant contribution of PMQ 2.0 and ABC-5. These findings indicate that WAS is a valid instrument and a better predictor of walking distance than PMQ 2.0 and ABC-5 in the lower limb prosthesis users.

Head-to-head Rasch comparison of the Prosthesis Evaluation Questionnaire-Mobility Section and the Prosthetic Mobility Questionnaire 2.0 in Italian lower-limb prosthesis users

“…In summary, this Rasch study demonstrated the good measurement quality of the PMQ 2.0, in line with other studies performed using Italian, 8 Slovene, 9-11 and German 12 versions. It also confirmed acceptable psychometric properties of the PEQ-MS, 5,22 despite some weakness in its item selection.…”

“…Nevertheless, our findings related to the psychometric characteristics of the investigated tools are in line with other studies using the same instruments, but performed in different contexts. 5,9,10,12 In summary, this Rasch study demonstrated the good measurement quality of the PMQ 2.0, in line with other studies performed using Italian, 8 Slovene, [9][10][11] and German 12 versions. It also confirmed acceptable psychometric properties of the PEQ-MS, 5,22 despite some weakness in its item selection.…”

“…This new version—PMQ 2.0 9 —confirmed its construct validity through convergence with other relevant outcome measures. 10,11 A German team performed a head-to-head Rasch validation of the PMQ 2.0 and the Locomotor Capabilities Index-5 in PwLLA, confirming the good measurement quality of the PMQ 2.0 (for unidimensionality, rating scale functioning, item fit, and reliability indices) and showing that its operational range is more suitable than the Locomotor Capabilities Index-5 for assessing people with advanced locomotor abilities. 12…”

“…Nevertheless, our findings related to the psychometric characteristics of the investigated tools are in line with other studies using the same instruments, but performed in different contexts. 5,9,10,12…”

Rasch validation and comparison of the German versions of the Locomotor Capabilities Index-5 and Prosthetic Mobility Questionnaire 2.0 in lower-limb prosthesis users

“…Two validated PROMs for measuring mobility with the prosthesis in people with LLA are the Locomotor Capabilities Index (LCI-5) [10,11] and the Prosthetic Mobility Questionnaire (PMQ 2.0) [12–14], which are available also in German versions: the former already published [15], while the latter submitted for publication (Ranker et al ., 2021, unpublished material). They are both promising tools but, so far, no head-to-head comparison of them has been performed.…”