Determinants of participation in patients with severe haemophilia.

The multifactorial nature of disability makes it difficult to point out a specific cause for limitations in participation. The conceptual framework of the WHO-ICF (International Classification of Function, Disability and Health) was used to study the determinants participation in patients with severe haemophilia. Outcome was assessed in a single-centre cohort of 124 patients with severe haemophilia. Joint mobility and muscle strength of the elbows, knees and ankles, in combination with recent X-ray findings (N = 39 only) and the MPQ-DLV pain questionnaire were used to assess Body Functions and Structures. Four performance-based functional tasks and the HAL questionnaire were used to assess Activities. The IPA questionnaire was used to assess Participation. Stepwise and hierarchical regression analysis adjusted for age and psychological health (Dutch-AIMS 2) was used to associate the various domains of the ICF. Irrespective of age, joint mobility was an important factor in explaining self-reported and performance-based activities. Muscle strength had no significant association with participation. Self-reported activities showed a stronger association with participation than performance-based activities. Adjusted for age and psychological health, joint mobility and pain explained none of the variation in participation. Self-reported activities, however, significantly contributed in explaining participation (25%), whereas performance-based activities (3%) did not. This study adds to the knowledge of determinants of participation in haemophilia. As the currently used instruments on joint status and activities only partially explain differences in participation, this aspect of clinical outcome should be included to fully assess outcome in haemophilia.