ICON 2020—International Scientific Tendinopathy Symposium Consensus: A Systematic Review of Outcome Measures Reported in Clinical Trials of Achilles Tendinopathy

Background: Nine core domains for tendinopathy have been identified. For Achilles tendinopathy there is large variation in outcome measures used, and how these fit into the core domains has not been investigated. Objective: To identify all available outcome measures outcome measures used to assess the clinical phenotype of Achilles tendinopathy in prospective studies and to map the outcomes measures into predefined health-related core domains. Design: Systematic review. Data Sources: Embase, MEDLINE (Ovid), Web of Science, CINAHL, The Cochrane Library, SPORTDiscus and Google Scholar. Eligibility Criteria for Selecting Studies: Clinical diagnosis of Achilles tendinopathy, sample size ≥ ten participants, age ≥ 16 years, and the study design was a randomized or non-randomized clinical trial, observational cohort, single-arm intervention, or case series. Results: 9376 studies were initially screened and 307 studies were finally included, totaling 13,248 participants. There were 233 (177 core domain) different outcome measures identified across all domains. For each core domain outcome measures were identified, with a range between 8 and 35 unique outcome measures utilized for each domain. The proportion of studies that included outcomes for predefined core domains ranged from 4% for the psychological factors domain to 72% for the disability domain. Conclusion: 233 unique outcome measures for Achilles tendinopathy were identified. Most frequently, outcome measures were used within the disability domain. Outcome measures assessing psychological factors were scarcely used. The next step in developing a core outcome set for Achilles tendinopathy is to engage patients, clinicians and researchers to reach consensus on key outcomes measures. Prospero Registration: CRD42020156763.