Functional Independence Score in Haemophilia: a new performance-based instrument to measure disability

Morbidity in haemophilia has been described predominantly in terms of musculoskeletal dysfunction and assessed by the clinical and radiological joint scores. These scores document changes in a particular joint, but do not reflect the impact of these changes on the individual in terms of his overall musculoskeletal function. Several self-assessment instruments have been used to measure musculoskeletal function but none have been specifically validated for use in haemophilia. In order to objectively assess musculoskeletal function of patients with haemophilia, we developed Functional Independence Score in Hemophilia (FISH), a performance-based instrument. FISH measures the patient's independence in performing seven activities under three categories: self-care (grooming and eating, bathing and dressing), transfers (chair and floor) and mobility (walking and step climbing). Each function is graded from 1 to 4 depending on the amount of assistance needed in performing the function. We evaluated 35 patients who were over 10 years old and had had at least three major bleeds per year. All subjects were scored for clinical (World Federation of Hemophilia, WFH score) and radiological changes (Pettersson's score). Functional independence of the patient was assessed using the Stanford Health Assessment Questionnaire (HAQ) and the FISH. Correlation of the FISH score was modest with both the WFH clinical score (r = -0.68) and the radiological score (r = -0.44). While there was good correlation between FISH and HAQ (r = -0.90), FISH had better internal consistency than HAQ (Cronbach's alpha 0.83 vs. 0.66). FISH appears to be a promising disease-specific instrument for assessing overall musculoskeletal function in haemophilia. It requires evaluation in different patient populations.