Feasibility, safety and acceptability of select outcome measures in a physiotherapy study protocol for boys with haemophilia

Background
There is a lack of functional performance measures for children and young people with haemophilia (CYPwH) with associated control data from typically developing boys (TDB). The literature advocates development of a core set of outcome measures for different chronic conditions. As medical treatment improves, CYPwH are experiencing better outcomes; therefore, more challenging measures are required to monitor physical performance. Such testing is not performed routinely, due to practical and safety concerns.

Aim
Evaluate the feasibility, safety and acceptability of select outcome measures as part of a study protocol testing CYPwH; including myometry, 10 metre incremental shuttle walk test (10-m ISWT), iSTEP (an incremental step test, with data from TDB), and 1 week of accelerometry-wear at home.

Methods
Sixty-six boys aged 6–15 years with mild, moderate or severe haemophilia A or B (including inhibitors) attending routine clinics at Great Ormond Street Hospital were approached to participate. Descriptive statistics and content analysis were used to assess outcomes of feasibility, safety and acceptability, which included recruitment/retention rates, protocol completion within routine appointment timeframes, performance testing without serious adverse events/reactions (SAE/SARs), and acceptability to CYPwH of high-level performance measures.

Results
Outcomes were met: 43 boys completed testing at clinic review (Jan–Nov 2018) within a 10-month timeframe, retention was 95% at completion of protocol and no SAE/SARs were reported throughout testing.

Conclusion
Feasibility, safety and acceptability of the study protocol have been established in this population. Both high-level performance tests, iSTEP and 10-m ISWT, were an acceptable addition to boys’ routine clinic appointments and could be safe, acceptable choices of outcome measure as part of a core set of tests for CYPwH. Further investigation of the psychometric properties for the iSTEP is now justified, in order for it to be used as a standardised, validated, reliable outcome measure in clinical or research settings.