The Influence of the Age of Adults with Sickle Cell Disease on the Uptake, Utilization and Efficacy of Hydroxyurea

Background Despite the efficacy of Hydroxyurea (HU) in decreasing morbidity and mortality in adults with sickle cell disease (SCD) the uptake of and adherence with HU is poor, probably as the result of a combination of both physician and patient related factors. Lack of knowledge about HU, doubts regarding effectiveness, concerns over side effects and unrealistic expectations from HU treatment have been previously identified as barriers to the wider uptake of HU by the patient. Since approval of HU for SCD by the FDA in 1998, there has been a progressive increase of the use of HU in SCD. Changes in approach and practice over this time may have impacted the attitude towards HU of patients of different ages differently. The impact of patients9 age on the uptake and utilization of HU has not been studied. We investigated the impact of age on the attitudes of adult patients towards the purpose, side effects, associated risks and benefits of taking HU. Methods We conducted qualitative interviews with adult SCD patients from a geographically diverse population recruited from national conferences and local SCD clinics. Data were gathered as part of a larger study of decision making regarding disease modifying therapies for SCD and development of a decision- aid tool for patients involving these disease-modifying therapies. We used a semi-structured open-ended interview guide to collect data. Audio recordings were transcribed verbatim. Transcripts were coded using qualitative content analysis with NVivo 11. We sought to understand attitudes of adult patients with SCD towards available treatment options. We then focused our analyses specifically on attitudes towards HU as a model for how SCD patients viewed their disease and treatment options. We also sought to interrogate differences in attitudes among patients who reached adulthood, before and after the general adoption of hydroxyurea as a treatment option for SCD. Results Age of the 95 participants ranged from 18 years to 67 years old. Female = 71. While approximately 50% of all participants reported that they were currently taking HU, younger participants were more likely to be currently taking HU than the older participants (p = .05). Seventy percent of the younger adults (Age 18-30) reported they were currently taking HU as compared to 41% of the older adults (Age 31-67) [table 1]. Younger participants were more likely to report that the decision to accept a physician recommendation to start HU was made by their parent, though some participants decided to start HU as a young adult. Younger participants understood the purpose of HU as intended to improve "blood counts" thereby decreasing crises and hospital stays. They were hopeful that HU would help and thus focused on the potential for successfully managing SCD complications rather than on the side effects from HU. For those who decided to start as young adults, they offered positive accounts in regards to the decision to start HU and maintain the treatment. In contrast, the older participants were not well informed about HU and reported a concern about taking a chemotherapy drug. Older adults currently taking HU were more likely to be skeptical about whether they were receiving any benefits from staying on the treatment. They were also less trusting than the younger participants, that all of the side effects from HU are known or that healthcare providers divulged them. Older participants were more likely than the younger participants to report advanced complications from SCD. They were also more likely to report an aversion to taking medications. Six older participants reported they tried HU past, but stopped taking the drug because of either bad side effects, lack of efficacy, or the belief that HU caused more crises. Conclusion The younger adults with SCD are more likely to have started HU as children and are more likely to be taking HU and believe in its efficacy while older adults were more skeptical about the efficacy of HU and the information they are provided by their healthcare providers. That so many older adults are concerned about the efficacy of HU also raises the question whether it HU is effective in the face of multi-organ complications. These data provide the rationale for a larger prospective study of the impact of age on both the attitudes and efficacy of HU. We believe that the data from this study will help tailor healthcare provider approaches to HU amongst older adults. Disclosures No relevant conflicts of interest to declare.