Psychometric analysis of the functional independence score in haemophilia (FISH)

Abstract

Joint morbidity in haemophilia has traditionally been measured using clinical and radiological scores. There have been no reliable, validated tools for the assessment of functional independence in persons with haemophilia till recently. The Functional Independence Score in Haemophilia (FISH) has been developed as a performance based assessment tool to address this need. The FISH is designed to measure the patient’s independence in performing activities of daily living (grooming and eating, bathing and dressing), transfers (chair and floor), and mobility (walking, step climbing and running). On assessment of its psychometric properties in 63 patients with haemophilia (mean age 14 years), FISH was found to have good internal consistency (Cronbach’s alpha of 0.85). It had moderate correlation with the World Federation of Hemophilia clinical score (r = −0.61), and a correlation with the Pettersson score of −0.38. It had good correlation with other self‐rated functional scores, such as the Stanford Health Assessment Questionnaire (r = −0.75); the Western Ontario and McMaster Universities Osteoarthritis Index (r = −0.66) and the Haemophilia Activities List (HAL) (r = −0.66). It had good reliability with a pooled intra class correlation of 0.98. On assessing responsiveness following treatment of flexion deformities of the knee in 12 patients, the FISH showed significant changes in the score with a standardized responsiveness mean of −1.93. In conclusion, the FISH was found to be a reliable and valid tool with good internal consistency and responsiveness to therapy, for the assessment of functional independence in persons with haemophilia.