Adherence to prophylactic infusions of factor VIII or factor IX for haemophilia.

Medication non-adherence is a true public health problem. Despite advancements in the molecular understanding of disease and improvements in therapy, patient health outcomes will not improve unless patients take prescribed medications. Decreasing the gap between efficacious and effective therapy for patients with haemophilia is an essential research agenda. Adherence is particularly important for patients on prophylaxis. Prophylactic infusion of factor VIII or IX has proven efficacy in preventing chronic joint disease and is considered the standard of care for children with severe haemophilia A and B [1,2]. However, the effectiveness of the prophylaxis depends on the recommendation of prophylaxis by the physician and adherence to the recommended regimen. Less than 40% of patients with severe haemophilia currently receive prophylaxis [3,4]. In a survey of haemophilia treatment centres, 37% of physicians reported that patient compliance was a barrier in implementing prophylactic therapy [5]. Haemophilia is a chronic disease, which requires long-term prophylactic therapy to prevent joint disease. Patients on primary prophylaxis are asymptomatic and may not see the benefits of prophylaxis. The treatment regimen is complex, requiring factor preparation and intravenous infusion. The treatment is also homebased so that it is not directly supervised by a physician or nurse. Previous adherence research in patients with haemophilia is limited. In 2003, Hacker et al. [6] published a cross-sectional study with of 38 haemophilia patients from the Mountain States Regional Haemophilia and Thrombosis Center. Only 58.8% of patients reported compliance of >75%. Barriers to compliance were time commitment, uncooperative child, and venous access. 8.3% did not believe that prophylaxis was necessary or beneficial. 44.1% agreed that understanding the benefits of prophylaxis improved compliance with prophylaxis. Based on this information, we hypothesized that time constraints and health beliefs may differ between adherent and non-adherent patients and may be studied using the health belief model (HBM). Important components of the model include an individual’s perceptions about (i) level of personal susceptibility to the particular illness or condition; (ii) degree of severity of the consequences (organic and/or social), which might result from contracting the condition; (iii) the health action’s potential benefits or efficacy in preventing or reducing susceptibility and/or severity; (iv) physical, psychological, financial, and other barriers or costs related to initiating or continuing the advocated behaviour. The HBM also stipulates that a cue to action or stimulus must occur to trigger the appropriate behaviour by making the individual consciously aware of his feelings about the health threat (Fig. 1) [7]. Time constraints are difficult to alleviate, but health beliefs may be modifiable, and further study of health beliefs may lead to interventions to improve adherence to prophylactic therapy. To study our hypotheses we conducted a single institution study at the University of Michigan Hemophilia Treatment Center. Twenty-two patients consented to participate in this IRB approved research study. The median age was 9 years (0.5– 39). Eight subjects are on primary prophylaxis, 14 subjects are on secondary prophylaxis, including two with history of intracranial haemorrhage. Five patients currently have ports. Seventeen patients receive factor infusions via peripheral vein and eight patients do self-infusion. Eight subjects infuse once a week, five patients infuse twice a week, and nine patients infuse three or more times per week. Correspondence: Courtney D. Thornburg MD, Duke University Medical Center, 214-A Bell Research Building, Trent Drive, Box 2916, Durham, NC 27710, USA. Tel.: +1 919 684 3401; fax: +1 919 681 7950; e-mail: [email protected]