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The Swedish version of OMAS is a reliable and valid outcome measure for patients with ankle fractures

Nilsson, Gertrud LU ; Eneroth, Magnus LU and Ekdahl, Charlotte LU (2013) In BMC Musculoskeletal Disorders 14.
Abstract
Background: The aim of this study was to evaluate the test-retest reliability and the validity of the self-reported questionnaire Olerud-Molander Ankle Score (OMAS) in subjects after an ankle fracture. Methods: When evaluating the test-retest reliability of the OMAS, 42 subjects surgically treated due to an ankle fracture participated 12 months after injury. OMAS was completed by the patients on two occasions at one to two weeks' interval. Concurrent criterion validity was evaluated using the five subscales of the Foot and Ankle Outcome Score (FAOS) and global self-rating function (GSRF), which is a five-grade Likert scale with the alternatives: "very good", "good", "fair", "poor", "very poor". Forty-six patients participated in the... (More)
Background: The aim of this study was to evaluate the test-retest reliability and the validity of the self-reported questionnaire Olerud-Molander Ankle Score (OMAS) in subjects after an ankle fracture. Methods: When evaluating the test-retest reliability of the OMAS, 42 subjects surgically treated due to an ankle fracture participated 12 months after injury. OMAS was completed by the patients on two occasions at one to two weeks' interval. Concurrent criterion validity was evaluated using the five subscales of the Foot and Ankle Outcome Score (FAOS) and global self-rating function (GSRF), which is a five-grade Likert scale with the alternatives: "very good", "good", "fair", "poor", "very poor". Forty-six patients participated in the validation against FAOS, and for GSRF 105 patients participated at 6 months and 99 at 12 months. Uni-, bi- and trimalleolar fractures were all included and both non-rigid and rigid surgical techniques were used. All fractures healed without complications. Before analysis of the results the five groups according to GSRF were reduced to three: "good", "fair" and "poor". Test-retest reliability was assessed using Spearman's rank correlation, the intraclass correlation coefficient (ICC), the standard error of measurement (SEM and SEM%) and the smallest real difference (SRD and SRD%). The Cronbach's alpha score and validity versus FAOS was assessed using Spearman's rank correlation and validity versus GSRF using the Kruskal-Wallis Test and the Mann-Whitney U-Test as ad hoc analyses. Results: The test-retest reliability correlation coefficient obtained was rho = 0.95 and ICC = 0.94. The SEM was 4.4 points and SEM% 5.8% and should be interpreted as the smallest change that indicates a real change of clinical interest for a group of subjects. The SRD was 12 points and SRD% 15.8% and should be interpreted as the smallest change that indicates a real change of clinical interest for a single subject. The correlation coefficients versus the five subscales of FAOS ranged from rho = 0.80 to 0.86. There were significant differences between GSRF groups "good", "fair" and "poor" (p < 0.001) at both the six-month and the 12-month follow-up. The internal consistency for the OMAS was 0.76. The effect size between results from 6-month and 12-month follow-up turned out be 0.44 and should be considered as medium. Conclusion: The results showed that the test-retest reliability of the Swedish version of OMAS was very high in subjects after an ankle fracture and the standard error of measurement was low. Furthermore the OMAS was found to be valid using both the five subscales of FAOS and the GSRF. The OMAS can thus be used as an outcome measure after an ankle fracture. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
Ankle fracture, OMAS, Reliability, Validity
in
BMC Musculoskeletal Disorders
volume
14
publisher
BioMed Central
external identifiers
  • wos:000316848500001
  • scopus:84875329036
ISSN
1471-2474
DOI
10.1186/1471-2474-14-109
language
English
LU publication?
yes
id
10ade015-39b3-4e4d-aa32-bf53ead3b0b8 (old id 3749118)
date added to LUP
2013-06-03 08:37:53
date last changed
2019-02-20 04:58:44
@article{10ade015-39b3-4e4d-aa32-bf53ead3b0b8,
  abstract     = {Background: The aim of this study was to evaluate the test-retest reliability and the validity of the self-reported questionnaire Olerud-Molander Ankle Score (OMAS) in subjects after an ankle fracture. Methods: When evaluating the test-retest reliability of the OMAS, 42 subjects surgically treated due to an ankle fracture participated 12 months after injury. OMAS was completed by the patients on two occasions at one to two weeks' interval. Concurrent criterion validity was evaluated using the five subscales of the Foot and Ankle Outcome Score (FAOS) and global self-rating function (GSRF), which is a five-grade Likert scale with the alternatives: "very good", "good", "fair", "poor", "very poor". Forty-six patients participated in the validation against FAOS, and for GSRF 105 patients participated at 6 months and 99 at 12 months. Uni-, bi- and trimalleolar fractures were all included and both non-rigid and rigid surgical techniques were used. All fractures healed without complications. Before analysis of the results the five groups according to GSRF were reduced to three: "good", "fair" and "poor". Test-retest reliability was assessed using Spearman's rank correlation, the intraclass correlation coefficient (ICC), the standard error of measurement (SEM and SEM%) and the smallest real difference (SRD and SRD%). The Cronbach's alpha score and validity versus FAOS was assessed using Spearman's rank correlation and validity versus GSRF using the Kruskal-Wallis Test and the Mann-Whitney U-Test as ad hoc analyses. Results: The test-retest reliability correlation coefficient obtained was rho = 0.95 and ICC = 0.94. The SEM was 4.4 points and SEM% 5.8% and should be interpreted as the smallest change that indicates a real change of clinical interest for a group of subjects. The SRD was 12 points and SRD% 15.8% and should be interpreted as the smallest change that indicates a real change of clinical interest for a single subject. The correlation coefficients versus the five subscales of FAOS ranged from rho = 0.80 to 0.86. There were significant differences between GSRF groups "good", "fair" and "poor" (p &lt; 0.001) at both the six-month and the 12-month follow-up. The internal consistency for the OMAS was 0.76. The effect size between results from 6-month and 12-month follow-up turned out be 0.44 and should be considered as medium. Conclusion: The results showed that the test-retest reliability of the Swedish version of OMAS was very high in subjects after an ankle fracture and the standard error of measurement was low. Furthermore the OMAS was found to be valid using both the five subscales of FAOS and the GSRF. The OMAS can thus be used as an outcome measure after an ankle fracture.},
  articleno    = {109},
  author       = {Nilsson, Gertrud and Eneroth, Magnus and Ekdahl, Charlotte},
  issn         = {1471-2474},
  keyword      = {Ankle fracture,OMAS,Reliability,Validity},
  language     = {eng},
  publisher    = {BioMed Central},
  series       = {BMC Musculoskeletal Disorders},
  title        = {The Swedish version of OMAS is a reliable and valid outcome measure for patients with ankle fractures},
  url          = {http://dx.doi.org/10.1186/1471-2474-14-109},
  volume       = {14},
  year         = {2013},
}