Patient reported outcome measures for ankle instability. An analysis of 17 existing questionnaires.

BACKGROUND: Patient reported outcome measures (PROMs) are essential for evaluating treatment of ankle instability (AI). The aim was to assess the content validity and the measurement properties of all relevant PROMs for AI. METHODS: Relevant PROMs were identified from PubMed and SCOPUS. The development and validation quality of the PROMs was assessed according to established scientific standards. RESULTS: Seventeen PROMs and 56 validation studies were analyzed. Content validity, which ensures the PROM measures what is relevant, is obtained by involving target patients in the development process. Only three PROMs identified had some degree of patient involvement (Cumberland Ankle Instability Tool (CAIT), Lower Extremity Function Scale (LEFS), and the Foot and Ankle Ability Measure (FAAM)). Of these, only FAAM was somewhat rigorously validated using modern psychometric validation methods, and exhibited superior measurement properties (construct validity). CONCLUSION: No existing PROM is completely adequate to evaluate AI. However, FAAM is the best choice.

Dual-panel translation to Danish and Rasch validation of the Foot and Ankle Ability Measure (FAAM-DK).

BACKGROUND: The Foot and Ankle Ability Measure (FAAM) was developed by involvement of patients with chronic ankle instability (CAI) and has acceptable measurement properties, but is not available in Danish. METHODS: FAAM was translated and culturally adapted into Danish, and its measurement properties were assessed using Rasch analyses. RESULTS: A Danish version was produced with small adaptations, and content relevance was confirmed by Danish patients. The 21-item ADL domain showed misfit to the Rasch model, but after removing six items, the resulting 15-item scale displayed adequate fit. The Sports domain also exhibited misfit, but after removing one item and adjusting due to differential item functioning related to age for another item, a 7-item scale showed good fit. This resulted in a 22-item 2-dimensional Danish version of FAAM. CONCLUSION: The 22-item Danish FAAM exhibits robust measurement properties for patients with various conditions of the lower leg, ankle, and foot, including CAI.