Barriers to adherence of deferoxamine usage in sickle cell disease.

Background: We hypothesized that child cognitive disability would be a significant risk factor for non-adherence with home deferoxamine (DFO) administration and that a factor that would contribute to improved adherence would be sharing of responsibilities for chelation between parents and patients. We explored the influences on adherence of behavioral and psychological adjustment; family stress; perceived convenience of and satisfaction with the DFO regimen; and parent and patient knowledge about DFO.

Procedure: Fifteen pediatric patients with sickle cell disease (SCD) who had evidence of excessive iron stores, and their parents, were interviewed about adherence and responsibility for chelation therapy. A neuropsychological assessment battery was administered to the patients. Family stress, the child's emotional and behavioral status, knowledge about chelation and iron overload were explored. Adherence was rated objectively using pharmacy refill patterns and observable signs of chelation.

Results: Sharing of responsibilities for chelation between parents and children was related to better adherence while neuropsychological status bore a complex relation to adherence. Of the exploratory variables, low family stress were related to better adherence while satisfaction with the home care regimen and convenience ratings were not useful in predicting adherence. No one element of adherence, even objective measures, was capable of classifying adherence, while a multifactorial scheme categorizing adherent, partially adherent and non-adherent groups demonstrated good face validity.

Conclusions: Supporting developmentally appropriate sharing of responsibilities for self-care is critical, taking patient neurocognitive status into consideration. Clinicians should evaluate adherence using a multifactorial model that highlights the most salient targets for intervention.