Development of a core set of outcomes for foot and ankle disorders in rheumatic and musculoskeletal diseases (COMFORT)

Background: Rheumatic and musculoskeletal diseases (RMDs) frequently affect the
foot and ankle, leading to pain, disability, and a reduction in quality of life, but there is a
lack of high-quality evidence to determine the effectiveness of treatments for foot and
ankle disorders. A contributing factor is heterogeneity in the domains (outcomes)
measured across research studies in this area. This hinders the ability to compare
study findings. Additionally, the domains measured may not be meaningful or relevant
to patients.

Aim: To develop a core set of outcomes for foot and ankle disorders in rheumatic and
musculoskeletal diseases (COMFORT).

Methods: COMFORT was developed with multidisciplinary, multi-contributor groups
using a rigorous evidence-based approach, which employed a mix of methods. A
systematic review and thematic synthesis of existing qualitative studies (n=34 studies)
explored patients’ symptoms and their impact, and identified gaps in the literature.
Patients’ experiences of foot and ankle problems in under-researched areas were
further explored in a secondary analysis of focus group data (n=40 patients), and a
primary qualitative interview study in eight countries (n=56 patients). Domains of
potential importance identified in the qualitative work were presented to patients,
healthcare professionals, and researchers in a modified Delphi consensus study,
consisting of four rounds of online surveys. Participants rated the importance of each
domain on a 9-point scale.

Findings: A total of 206 participants representing 22 countries completed at least one
round of the Delphi study. Consensus was reached on the inclusion of five core
domains: pain intensity, pain when weightbearing, physical function (activities and
participation), joint movement, and treatment satisfaction. Two circumstance-specific
domains were also included: structural pathology and healthcare expenses. Finally,
four domains were considered important for future consideration: emotional wellbeing,
sleep, gait, footwear.

Conclusion: This project developed a standardised, internationally agreed set of
domains for measurement in future research. Its uptake has the potential to improve
the quality of evidence for foot and ankle RMD treatments. Future work will focus on
standardising outcome measurement instruments for the core domains. Crucially, the
involvement of patients in the design and conduct of each phase of this project ensures
that future research findings will reflect what outcomes are meaningful and relevant to
those with foot and ankle disorders in RMDs.