Multidimensional Assessment of Chronic Pain in Severe Haemophilia A

Multidimensional Assessment of Chronic Pain in Severe Haemophilia A Treated With Monoclonal Antibodies: an Observational Study; an Ambispective Cohort Study

Introduction: Haemophilia is a congenital coagulopathy characterised by haemarthrosis, mainly in the knees, ankles and elbows. Prophylactic treatment is the most effective therapeutic option for preventing or minimising these bleeds. Bispecific monoclonal antibodies have been shown to be effective in reducing bleeding in patients with haemophilia.

Objectives: To investigate the associations between chronic residual pain and pain catastrophising, perceived self-efficacy regarding the disease and treatment, and body image and perception of visible disability.

Methods. Multicentre cross-sectional cohort studies. 109 patients with severe haemophilia A from different regions of Spain will be included in the study. The primary variable will be chronic residual pain and its functional interference (Brief Pain Inventory-Short Form). Secondary variables will be pain catastrophising (Pain Catastrophising Scale), perceived self-efficacy regarding the disease and treatment (Pain Self-Efficacy Questionnaire), and body image and perception of visible disability (Body Image Scale). Potential confounding variables will include sociodemographic variables (age and educational level), clinical variables (time on monoclonal antibody treatment and number of previous bleeds in the last 12 months) and anthropometric variables (body mass index).

Expected results: It is expected that residual chronic pain will persist in patients with severe haemophilia A treated with monoclonal antibodies and that it will be associated with greater catastrophising, lower self-efficacy and poorer body image, modulating the experience of pain beyond bleeding control.

Inclusion Criteria:

• Patients over 18 years of age.
• With a medical diagnosis of severe haemophilia A (FVIII < 1%).
• No inhibitors to FVIII concentrates at the time of the study.
• At least 3 months of treatment with bispecific monoclonal antibodies.
• Medical diagnosis of haemophilic arthropathy in at least two lower limb joints and ≥5 points on the Haemophilia Joint Health Score.
• Ability to understand and respond to self-administered questionnaires.

Exclusion Criteria:

• Patients diagnosed with severe musculoskeletal or neurological comorbidities causing chronic pain.
• Individuals with neurological or cognitive impairments that prevent them from understanding the questionnaires.
• Patients who have participated in an interventional clinical study in the 6 months prior to the study.