Objective:
Adherence to treatment has an important impact on health outcomes in chronic conditions, but the relationship between adherence to prophylactic infusions and outcomes in hemophilia is not well documented. This study was conducted to assess the relationship between adherence to prophylaxis and outcomes, including patient-reported health status and bleeding.
Methods:
Adults with hemophilia and parents of minors with hemophilia were identified through a panel of patients originally recruited from hemophilia treatment centres and associations. Panelists reporting moderate or severe hemophilia completed an on-line questionnaire, which included the Validated Hemophilia Regimen Treatment Adherence Scale-Prophylaxis (VERITAS-Pro) for adherence to prophylactic treatment, a measure of health status (adults: SF-12v2 questionnaire; parents of pediatric patients: SF-10) and items assessing the number of times they experienced clinical outcomes, such as breakthrough bleeds, ER visits, hospital admissions, and missed days from work/school due to bleeding episodes. All measures were through self- or parent-report. Generalized linear models were used to assess the relationship between adherence and outcomes, adjusting for age (adults only). The protocol and questionnaire were approved by an institutional review board and all respondents provided informed consent.
Summary (of results obtained):
A total of 53 adults with hemophilia A (n=43) or B (n=10) treated with prophylaxis completed the survey and provided age information. In analyses combining these groups, lower adherence was associated with more days of work or school missed due to bleeding episodes in the past year (p<0.05), as well as the number of bleeding episodes requiring administration of replacement factor in the past year (p<0.001). The relationship between adherence and bleeding episodes was also significant in analyses separating A and B patients (p<0.01 and p<0.05, respectively), as was the link between adherence and days missed in hemophilia A (p<0.05). Adherence was not significantly associated with physical health status (p=0.91) among adults. Among pediatric patients treated with prophylaxis (n=56), the relationship between adherence and number of bleeding episodes in the past year was not significant (p= 0.95). Adherence was associated with clinical outcomes related to bleeding episodes over the past year, such as infection at the injection site (p<0.05), hospital stay due to bleeding episodes (p<0.001), and missed days from work/school due to bleeding episodes (p<0.01). Furthermore, physical health status was better among more-adherent pediatric patients (p<0.01).
Conclusions:
Though sample sizes were limited, greater adherence to prophylaxis was associated with better self-reported clinical outcomes among both adult and pediatric hemophilia patients.