Functional consequences of haemophilia in adults: the development of the Haemophilia Activities List.

Several instruments can be used to evaluate the functional status of patients with haemophilia, but none of these instruments is specific for haemophilia. We developed a haemophilia-specific self-assessment questionnaire to evaluate and monitor a patient's perceived functional health status: the Haemophilia Activities List (HAL). In three separate but interlinked substudies, the questionnaire was constructed and tested for face, expert, and convergent validity, as well as internal consistency and patient-evaluated relevance. Items for the questionnaire were collected by interviewing 162 patients, using the McMaster-Toronto Arthritis Patient Preference Disability Questionnaire (MACTAR). The items were combined to generate the first version of the questionnaire [HAL(1)]. This version was evaluated and commented on by two focus groups (patients and caregivers), and then the questionnaire was adapted on the basis of these comments, forming the final version, HAL(2). This version was then validated in a pilot study with 50 consecutive patients using the Dutch Arthritis Impact Measurements Scales 2 (Dutch-AIMS2) and the Impact on Participation and Autonomy (IPA) questionnaires. The HAL(2) showed good convergent validity (Pearson correlation 0.80-0.91; P < 0.01), and the internal consistency was good for six of the eight domains (Cronbach's alpha 0.83-0.95). Patients considered the content of the HAL to be more relevant to their situation than the content of the other questionnaires (P < 0.01). Three major factors (upper extremity function, lower extremity function, key activities/major problem activities) were identified by factor analysis. The questionnaire seems to be a useful tool to identify problematic activities as part of the functional health status of patients with haemophilia. The construct validity, test-retest reliability, and responsiveness of the HAL will be established in the future.