Responsiveness and Minimal Important Change of the Haemophilia Activities List in Patients With Inherited Bleeding Disorders

Introduction: The Haemophilia Activities List (HAL) is a disease-specific patient-reported outcome measure (PROM) that is widely used in both healthcare and research in people with inherited bleeding disorders (PWBD), but information on responsiveness and minimal important change (MIC) is lacking. Aim: The aim of this study is to determine the responsiveness and MIC of the HAL to measure self-reported limitations in activities in PWBD. Methods: PWBD on the waiting list for orthopaedic surgery were invited to participate. Participants completed the HAL, reference PROMs regarding pain, physical functioning and ADL activities at baseline, 3 months and 12 months after surgery. The general perceived effect was completed at 3 and 12 months after surgery. Results: A total of 32 surgeries performed in 28 participants were included. Three months after surgery the change of the HAL sum score showed moderate to strong correlation with the change on the physical functioning PROMs (r: 0.56) and the change on the ADL PROMs (r: 0.65) and weak correlation with pain scores. The HAL was well able to discriminate participants that improved in self-reported limitations in activities and participation from those that did not improve (AUC: 0.86 (95%CI: 0.71–1.0)). The MIC_improvement was −2.3 (95%CI: −6.0;1.4) and the MIC_{deterioriation} −4.9 (95%CI: −8.4;−2.5). Conclusion: As the MIC is smaller than the smallest detectable change (SDC) of the HAL, it can be assumed that if a person has improved or deteriorated more than the known SDC of 10.2 (previous research), they are likely to experience a meaningful change over time.