The use of a disability model in haemophilia research.

Most haemophilia research is medically orientated. However, assessment of the impact of disease on the individual is different when viewed from a rehabilitation perspective. Several models are available to explore functioning and health from this perspective. The disablement process (DP) is such a model, and the aim of this study was to introduce this process in haemophilia research to see whether this type of research could lead to meaningful data. Forty-three adult patients with severe haemophilia participated in this study in which the three 'main pathway' domains of the DP (impairments, functional limitations and disability) and two additional factors (intra-individual and risk factors) were addressed. Three questionnaires (HAL, Dutch-AIMS2 and IPA) were incorporated, and Pettersson scores for 21 patients were retrieved. Step-wise and hierarchical regression analysis was used to assess relationship between the various domains. Arthropathy explained 48% of the variance in functional limitations and nearly 25% of the variance in disability. Functional limitations explained 54% of the variance in disability. Patients identified pain as an important aspect of health which addressed 22% and 13% of the variance in functional limitations and disability respectively. Age was correlated with arthropathy (r = 0.85; P < 0.001), whereas psychological health correlated with pain (r = 0.67; P < 0.001). Both variables were also correlated with functional limitations and disability. Analyses adjusting for the effects of age and psychological health were subsequently performed resulting in more insight in the associations within the DP. The use of the DP in haemophilia research proved to be useful.