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

Abstract

BackgroundThe 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.MethodsWhen 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.ResultsThe 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.ConclusionThe 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.

Translation, cross-cultural adaptation, reliability and validity of the Turkish version of the Olerud-Molander Ankle Score (OMAS)

“…In this version, the test-retest reliability was calculated using both the Spearman rank correlation coefficient and ICC. 17 The authors reported excellent values of rho = 0.95 and ICC = 0.94, which are similar to our results. The first assessment of the OMAS-TR was completed at the clinic and the second assessment via phone interview with a total of 100 patients.…”

“…These are not major or relevant complaints of patients with ankle fractures. On the other hand, Nilsson et al 17 reported that the correlation between the Swedish version OMAS and FAOS-ADL and FAOS-S subscales were 0.80 and 0.85, respectively, which is very similar to our validation results with the OMAS-TR and FAAM subscales. In addition, to determine convergent and divergent validity, we determined the level of associations between the scores on the OMAS-TR and the two summary scores for the SF-12.…”

“… 16 The English version of the OMAS has only been translated into Swedish. 17 The Turkish version of the OMAS would potentially be a PRO measure that would be useful in the clinical management of Turkish-speaking patients with various ankle fractures.…”

Weight-Bearing and Mobilization in the Postoperative Care of Ankle Fractures: A Systematic Review and Meta-Analysis of Randomized Controlled Trials and Cohort Studies

“…Nilsson et al suggested that a difference of 4.4 points in the Olerud Molander score is of clinical interest for a group of patients [ 52 ]. This meta-analysis shows an even greater difference in the Olerud Molander score of 6.88 points on short-term in favour of active mobilization and 8.00 points on long-term in favour of early weight-bearing.…”

The Ankle Injury Management (AIM) trial: a pragmatic, multicentre, equivalence randomised controlled trial and economic evaluation comparing close contact casting with open surgical reduction and internal fixation in the treatment of unstable ankle fractures in patients aged over 60 years

“…112 More recently, additional evidence supporting the validity and reliability of the OMAS has been published. 113 In the context of the AIM trial, the conclusions drawn from the OMASs are supported by the high precision of estimates and the consistency with the secondary outcomes [SF-12 (mental and physical), EQ-5D and EQ-5D VAS, timed up and go test, ankle range of motion and pain].…”