Abstract
Objective
To assess construct validity of the Prosthetic Limb Users Survey of Mobility (PLUS-M),
a self-report mobility measure for people with lower limb amputation (LLA).
Design
Cross-sectional study.
Setting
Private prosthetic clinics (n=37).
Participants
Current lower limb prosthesis users (N=199; mean age ± SD, 55.4±14.3y; 71.4% men)
were assessed before receiving a replacement prosthesis, prosthetic socket, and/or
prosthetic knee.
Interventions
Not applicable.
Main Outcome Measures
Convergent construct validity was examined using correlations between participants'
PLUS-M T-scores and measures of physical function, mobility, and balance, including
the Amputee Mobility Predictor (AMP), timed Up and Go (TUG), Patient-Reported Outcomes
Measurement Information System–Physical Function (PROMIS-PF), Prosthesis Evaluation
Questionnaire–Mobility Subscale (PEQ-MS), and Activities-specific Balance Confidence
(ABC) Scale. Known-groups construct validity was evaluated by comparing differences
in PLUS-M T-scores among participants grouped by Medicare Functional Classification
Level (MFCL).
Results
PLUS-M T-scores demonstrated a moderate positive relationship with AMP scores (ρ=.54,
P<.001) and a moderate negative relationship with TUG times (ρ=−.56, P<.001). The PLUS-M also showed a strong positive relationship with PEQ-MS scores (ρ=.78,
P<.001), ABC Scale scores (ρ=.81, P<.001), and PROMIS-PF T-scores (ρ=.81, P<.001). Significant differences (P<.05) in PLUS-M T-scores were found among groups of people classified by different
MFCLs.
Conclusions
Study results support the validity of the PLUS-M as a self-report measure of prosthetic
mobility. Correlations between PLUS-M and measures of physical function, mobility,
and balance indicate convergent construct validity. Similarly, significant differences
in PLUS-M T-scores across MFCL groups provide evidence of known-groups construct validity.
In summary, evidence indicates that PLUS-M has good construct validity among people
with LLA.
Keywords
List of abbreviations:
ABC (Activities-specific Balance Confidence), AMP (Amputee Mobility Predictor), LLA (lower limb amputation), MFCL (Medicare Functional Classification Level), PEQ-MS (Prosthesis Evaluation Questionnaire–Mobility Subscale), PLUS-M (Prosthetic Limb Users Survey of Mobility), PROMIS (Patient-Reported Outcomes Measurement Information System), PROMIS-PF (Patient-Reported Outcomes Measurement Information System–Physical Function), TUG (timed Up and Go)To read this article in full you will need to make a payment
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Article info
Publication history
Published online: August 30, 2016
Footnotes
Supported by the Eunice Kennedy Shriver National Institute of Child Health and Human Development of the National Institutes of Health (award no. R01HD065340). The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health.
Clinical Trial Registration No.: NCT01750372.
Disclosures: none.
Identification
Copyright
© 2016 by the American Congress of Rehabilitation Medicine
