Study design: Cohort study of subjects with insertional Achilles tendinopathy (IAT).
Objectives: The purpose of this study was to establish the minimum clinically important difference (MCID) on the Victorian Institute of Sport Assessment - Achilles Questionnaire (VISA-A) and the Lower Extremity Functional Scale (LEFS) for patients with IAT.
Background: The VISA-A and LEFS are two measures commonly utilized for patients with IAT. Previous authors have estimated the MCID for the VISA-A, but a MCID has not been formally established. The MCID for the LEFS has been established for patients with lower extremity conditions in general, but it is not clear if this MCID is applicable to patients with IAT.
Methods: Fifteen subjects participating in a randomized controlled trial studying the effectiveness of intervention for IAT over a 12-week period were included in this study. Subjects completed the VISA-A and LEFS forms at baseline and 12 weeks after the initiation of treatment. All subjects also completed a 15-point global rating of change (GROC) questionnaire at 12 weeks after the initiation of treatment. Subjects were classified as improved or stable based on their GROC scores.
Results: The area under the curve (AUC) for the VISA-A was 0.97 and a MCID of 6.5 points was identified. The AUC for the LEFS was 0.97 and a MCID of 12 points was identified.
Conclusion: The VISA-A and LEFS are both useful outcome measures to assess response in patients with IAT.
Level of evidence: 3.
Keywords: Achilles tendinopathy; LEFS; MCID; VISA‐A.