Identifying performance-based outcome measures of physical function in people with haemophilia (IPOP)

Introduction: Recent recommendations of core outcome sets for haemophilia highlight the need for including measures of performance-based physical health and physical function sustainability. To date, there is no consensus on what outcomes might be of value to clinicians and patients. Aim: To identify instruments of performance-based physical function to monitor musculoskeletal health in people with haemophilia that are practical in the clinical setting. Methods: Utilising components from the Activities and Participation Category of the WHO International Classification of Functioning (WHO-ICF), a consensus-based, decision analysis approach was used to: identify activities people with haemophilia have most difficulty performing; identify quantitative performance-based measures of identified activities via a scoping review; and obtain views on acceptability of the tests utilising a DELPHI approach. Results: Eleven activities were identified: maintaining a standing position, walking long distances, walking up and down stairs, walking on different surfaces, running, hopping, jumping, squatting, kneeling, undertaking a complex lower limb task, undertaking a complex upper limb task. Following a 2-round DELPHI survey of international physiotherapists, the 6-min walk test, timed up and down stairs, 30-s sit to stand, single leg stance, tandem stance, single hop for distance (children only) and timed up and go (adults only) reached consensus. Conclusion: This study is the first step in defining a core set of performance-based instruments to monitor physical health and sustainability of physical function outcomes in people with haemophilia. Establishing the psychometric properties of the instruments and whether they are meaningful to people with haemophilia is essential.