Development of a Core Outcome Set for Children's Elective Lower Limb Orthopaedic Surgery (CELLOS Study)

Background In the financial year 2018/2019, over 70,000 children's elective lower limb orthopaedic surgeries (CELLOS) were performed in England.

This incorporates surgeries for a range of conditions including cerebral palsy, metabolic bone disease, and congenital deformities, all of which can cause long-term disability.

There are often different surgical options, therefore having access to high-quality research that compares different surgeries is required to guide evidence-based care.

However, paediatric orthopaedic research is often not high-quality; identified methodological issues include inconsistent outcome selection, and inappropriate use of outcome measurements.

Improving outcome and outcome measurement selection for CELLOS can be achieved through the development of a core outcome set (COS).

A COS is a standardised collection of outcomes which have been identified through a consensus process involving all relevant stakeholders as the most important for the patient group.

Research Aim To establish the most important outcomes for CELLOS for all relevant stakeholders, and how and when should these be measured.

Methods This project will follow recommended methods for developing a COS from the Core Outcome Measures in Effectiveness Trials (COMET) handbook. The protocol will be published in advance following protocol reporting guidelines.

Study 1: A scoping review of CELLOS will be conducted to list outcomes measured in clinical trials and identified in qualitative research in the past five years.

Study 2: Semi-structured interviews will be conducted to identify further outcomes important to relevant UK-based stakeholders.

Stakeholders will include: patients currently aged 8-25 who had orthopaedic surgery aged 0-18, their parents and caregivers, and orthopaedic surgeons. Interviews with allied health professionals (AHPs) have been conducted prior.

Study 3: An international Delphi survey will be conducted using all identified outcomes in Studies 1&2 to establish a short list of the most important outcomes. This will involve the same stakeholder groups plus paediatric orthopaedic researchers and AHPs.

Study 4: Three international consensus meetings will be held with a maximum variation sample of stakeholders: Meeting One: Will seek consensus on the most important outcomes. A review of previously used relevant outcome measurement tools will be conducted between meetings.

Meeting Two: The participants will be informed of the review results, and consensus on outcome measures for each outcome will be sought. Meeting Three: Will seek a consensus on when outcomes should be measured.

Anticipated Impact and Dissemination The development of a COS will improve evidence for CELLOS, and delivery of children's orthopaedic services, through: Stakeholder involvement in the selection of outcomes and outcome measurement tools for clinical trials, quality improvement projects and clinical audits.

Reducing reporting bias as minimum outcomes to be reported are established. Improving the strength of evidence from systematic reviews as more results can be synthesised. Reducing research and clinical resource waste through repeatedly establishing important outcomes for CELLOS.

I will publicise findings to achieve this impact through presentations at three international conferences, four open access publications in peer-reviewed journals, dissemination materials including an animated video distributed through social media, lay publications in charity magazines, and public involvement activities in schools and local science fairs.