Content Relevance of the Foot and Ankle Ability Measure in Patients With Achilles Tendon Diseases

Background. The Foot and Ankle Ability Measure (FAAM) is among the most widely utilized and best psychometrically supported lower extremity–specific patient-reported outcome measures. However, its content relevance has never been directly subjected to patient assessment. Methods. This was an institutional review board–approved, prospective, cross-sectional study of 75 patients with Achilles tendon diseases who ranked the relevance of the FAAM’s items and subscales as 1 = Not relevant, 2 = Somewhat relevant, or 3 = Very relevant. Substantial content relevance was indicated by a minimum mean item or subscale score of 2.0. Nonsurgical and surgical subgroups were compared. Results. At the whole group level, the mean score was above 2.0 for each individual item and subscale. Subgroup analysis revealed that the mean relevance was above 2.0 for each of the items and subscales with the exception of the “Personal Care” item, which nonsurgical patients ranked significantly lower than did surgical patients (mean = 1.74 vs 2.23, P =.02). Additionally, this was part of a general trend across items with more 95% confidence intervals crossing below 2.0 in the nonsurgical data set (15 items, 52%) than the surgical data set (1 item, 3%). Conclusion. These data confirm that the FAAM has substantial content relevance to patients with Achilles tendon diseases. However, it is unclear why the surgical subgroup consistently ranked items higher than did the nonsurgical subgroup. Future work should address how a patient’s content relevance perception is influenced by the relative effects of their Achilles disease type and their perceived level of disease-related functional impairment. Levels of Evidence: Diagnostic, Level III.