Development of a core outcome set for lateral elbow tendinopathy (COS-LET) using best available evidence and an international consensus process

Objectives To develop a core outcome set for lateral elbow tendinopathy (COS-LET) and to provide guidance for outcome evaluation in future studies.

Methods We implemented a multi-stage mixed-methods design combining two systematic reviews, domain mapping of outcome measurement instruments to the core domains of tendinopathy, psychometric analysis of instruments, two patient focus groups and a Delphi study incorporating two surveys and an international consensus meeting. Following the OMERACT guidelines, we used a 70% threshold for consensus.

Results 38 clinicians/researchers and 9 patients participated. 60 instruments were assessed for inclusion. The only instrument that was recommended for the COS-LET was Patient Rated Tennis Elbow Evaluation (PRTEE) for the disability domain. Interim recommendations were made to use: the PRTEE function subscale for the function domain; PRTEE pain subscale items 1, 4 and 5 for the pain over a specified time domain; pain-free grip strength for the physical function capacity domain; a Numerical Rating Scale measuring pain on gripping for the pain on activity/loading domain; and time off work for the participation in life activities domain. No recommendations could be made for the quality-of-life, patient rating of condition and psychological factors domains.

Conclusions The COS-LET comprises the PRTEE for the disability domain. Interim-use recommendations included PRTEE subscales, time off work, pain-free grip strength and a Numerical Rating Scale measuring pain on gripping. Further work is required to validate these interim measures and develop suitable measures to capture the other domains.


Marcus Bateman, Jonathan P Evans, Viana Vuvan, Val Jones, Adam C Watts, Joideep Phadnis, Leanne M Bisset, Bill Vicenzino, COS-LET Authorship Group


Journal: British Journal of Sports Medicine
Pages: -
Year: 2022
DOI: 10.1136/bjsports-2021-105044

Further Study Information

Current Stage: Completed
Date: November 2019 - 2021
Funding source(s): None

Health Area

Disease Category: Orthopaedics & trauma

Disease Name: Lateral elbow tendinopathy (Tennis elbow)

Target Population

Age Range: 18 - 100

Sex: Either

Nature of Intervention: Any

Stakeholders Involved

- Clinical experts
- Consumers (patients)
- Researchers

Study Type

- COS for clinical trials or clinical research
- Recommendations for outcome measures (measurement/how)


- Consensus meeting
- Delphi process
- Survey
- Systematic review

Stage 1: A systematic review and standardised comparison of English language clinical rating systems used in LET has already been completed with searches up to 2017 (Evans et al, 2019). In the original search only measures of function and disability were included. The searches will be re-run up to 2020 and all outcome measurement instruments will be extracted.
Stage 2: The Steering Group will apply the OMERACT truth and feasibility filters to map the instruments to the nine core tendinopathy domains (Vicenzino et al, 2019) and instruments failing to meet the green or amber thresholds will be excluded.

Stage 3: A two-round online Delphi survey will be conducted followed by a third-round final consensus meeting. International clinical and research experts in the field of LET will be invited to participate along with patient representatives who have experienced the condition. The Delphi Study will apply the OMERACT Truth, Feasibility and Discrimination filters to each of the instruments selected in Stage 2 resulting in an overall rating of individual instrument properties. Consensus will be determined by a 70% threshold. If agreement is <30% the instrument will be excluded. Any instruments with a 30-69% consensus will be discussed and voted on again.

Stage 4: The steering committee will prepare the final report containing the recommended minimum Core Outcome Set for Lateral Elbow Tendinopathy based upon the nine core tendinopathy domains. This will be disseminated in a high quality peer-reviewed journal and presented at international conferences.

Ethical approval has been granted by the University of Queensland, Australia (reference 2020001340).