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Psychometric Properties of the Walking Impact Scale (Walk-12) in Persons with Late Effects of Polio

Brogårdh, Christina LU ; Lexell, Jan LU and Westergren, Albert LU (2021) In PM and R 13(3). p.297-306
Abstract

Background: Many persons with late effects of polio (LEoP) perceive walking limitations in everyday life. A common rating scale to assess walking limitations is the Walking Impact Scale (Walk-12). However, there is limited knowledge about its psychometric properties. Objective: To investigate the psychometric properties of Walk-12 in persons with LEoP. Design: Rasch model analysis of cross-sectional data. Setting: University hospital. Participants: A total of 325 persons with LEoP (175 women; mean age 70 ± 10 years). Main Outcome Measurement: The Walk-12, comprising 12 items with five response categories ranging from 1 (not at all) to 5 (extremely). Methods: Data of Walk-12 were collected by a postal survey. The Rasch model analysis was... (More)

Background: Many persons with late effects of polio (LEoP) perceive walking limitations in everyday life. A common rating scale to assess walking limitations is the Walking Impact Scale (Walk-12). However, there is limited knowledge about its psychometric properties. Objective: To investigate the psychometric properties of Walk-12 in persons with LEoP. Design: Rasch model analysis of cross-sectional data. Setting: University hospital. Participants: A total of 325 persons with LEoP (175 women; mean age 70 ± 10 years). Main Outcome Measurement: The Walk-12, comprising 12 items with five response categories ranging from 1 (not at all) to 5 (extremely). Methods: Data of Walk-12 were collected by a postal survey. The Rasch model analysis was used to analyze unidimensionality of the scale, local dependency, targeting, hierarchical order of items, Differential Item Functioning (DIF), response category functioning, and reliability (Person Separation Index, PSI). Raw score transformation to interval measurements was also performed. Results: The analysis revealed that Walk-12 was multidimensional and suffered from some local dependency. Targeting was compromised among persons with less and more walking limitations. Hierarchically, the most difficult item to perform was “running” and the easiest was “walking indoors with support”. There was a minor DIF for gender in one item (“support when walking outdoors”). Reliability was high (PSI = 0.94). Disordered response category thresholds were found for three items; when merging the middle response categories for these items model fit slightly improved and unidimensionality was achieved. Conclusions: The Walk-12, in its current version, does not fully meet the rigorous psychometric Rasch measurement standards in persons with LEoP. Further development of the scale is warranted, including merging response categories and complementing Walk-12 with objective measures of gait in order to improve targeting. As these limitations can be considered minor, the current version of Walk-12 can still be useful for research and clinical practice.

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author
; and
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
PM and R
volume
13
issue
3
pages
10 pages
publisher
Wiley-Blackwell
external identifiers
  • scopus:85102325026
  • pmid:32410316
ISSN
1934-1482
DOI
10.1002/pmrj.12403
language
English
LU publication?
yes
id
3c0626b5-86e3-4cb5-80dd-7a49d1110bb5
date added to LUP
2021-03-24 14:16:47
date last changed
2024-04-06 01:02:25
@article{3c0626b5-86e3-4cb5-80dd-7a49d1110bb5,
  abstract     = {{<p>Background: Many persons with late effects of polio (LEoP) perceive walking limitations in everyday life. A common rating scale to assess walking limitations is the Walking Impact Scale (Walk-12). However, there is limited knowledge about its psychometric properties. Objective: To investigate the psychometric properties of Walk-12 in persons with LEoP. Design: Rasch model analysis of cross-sectional data. Setting: University hospital. Participants: A total of 325 persons with LEoP (175 women; mean age 70 ± 10 years). Main Outcome Measurement: The Walk-12, comprising 12 items with five response categories ranging from 1 (not at all) to 5 (extremely). Methods: Data of Walk-12 were collected by a postal survey. The Rasch model analysis was used to analyze unidimensionality of the scale, local dependency, targeting, hierarchical order of items, Differential Item Functioning (DIF), response category functioning, and reliability (Person Separation Index, PSI). Raw score transformation to interval measurements was also performed. Results: The analysis revealed that Walk-12 was multidimensional and suffered from some local dependency. Targeting was compromised among persons with less and more walking limitations. Hierarchically, the most difficult item to perform was “running” and the easiest was “walking indoors with support”. There was a minor DIF for gender in one item (“support when walking outdoors”). Reliability was high (PSI = 0.94). Disordered response category thresholds were found for three items; when merging the middle response categories for these items model fit slightly improved and unidimensionality was achieved. Conclusions: The Walk-12, in its current version, does not fully meet the rigorous psychometric Rasch measurement standards in persons with LEoP. Further development of the scale is warranted, including merging response categories and complementing Walk-12 with objective measures of gait in order to improve targeting. As these limitations can be considered minor, the current version of Walk-12 can still be useful for research and clinical practice.</p>}},
  author       = {{Brogårdh, Christina and Lexell, Jan and Westergren, Albert}},
  issn         = {{1934-1482}},
  language     = {{eng}},
  number       = {{3}},
  pages        = {{297--306}},
  publisher    = {{Wiley-Blackwell}},
  series       = {{PM and R}},
  title        = {{Psychometric Properties of the Walking Impact Scale (Walk-12) in Persons with Late Effects of Polio}},
  url          = {{http://dx.doi.org/10.1002/pmrj.12403}},
  doi          = {{10.1002/pmrj.12403}},
  volume       = {{13}},
  year         = {{2021}},
}