Barriers to the Use of Disease-Modifying Treatments in Sickle Cell Disease: A Survey of Patients and Caregivers

Introduction

Sickle cell disease (SCD) is the most common hemoglobinopathy in the United States, characterized by significant morbidity and mortality. In the absence of widespread curative therapies, disease modifying therapies (DMTs) are important treatment options to manage disease complications and improve outcomes. Despite the demonstrated benefits of DMTs and the recent approval of new DMTs, these treatments are still underutilized among SCD patients. Thus, understanding barriers to use can be informative in the design of strategies to improve utilization. This study improves upon previous barrier analyses through the use of a behavioral theory-informed theoretical framework to assess barriers to DMTs. We used the theoretical domains framework (TDF) , which has been effective at targeting barriers amenable to interventions in health services research. In this study, we sought to identify barriers to DMT use among SCD patients/caregivers.

Methods

A cross-sectional web-based survey was conducted (April 2022- July 2022). A comprehensive set of questions were developed for each of the 14 domains contained in the TDF by the investigative team. Final survey items were decided based on relevancy, alignment to the research objective and clarity. Survey items assessed sociodemographic information, DMT use, attitudes and beliefs towards DMTs, and health-system related factors. All questions were close-ended and were evaluated with a 5-point Likert-scale response. Survey responses were summarized descriptively. For each survey statement/question, Likert scale responses were categorized as negative, neutral, or positive. Negative categories included a score of 1 (strongly disagree) or 2 (disagree); neutral included a score of 3 (neither agree or disagree); and positive included a score of 4 (agree) or 5 (strongly agree).

Results

A total of 100 patients/caregivers completed the survey. Sociodemographic information revealed that 54% of respondents have a primary care provider and a hematologist, 91% of respondents have some form of insurance coverage with the majority having commercial insurance (26%) or Medicaid (25%). Additionally, 63% of respondents reported current use of a DMT. Hydroxyurea was the most commonly used DMT (51%) followed by voxelotor (13%). Domain analyses revealed notable findings within 4 domains: knowledge, reinforcement, beliefs about consequences, and environmental. Specifically, 79.4% of responders reported having a good understanding of DMTs and 64.2% stated they need more information about DMTs. Sixty-three percent of participants believe that DMTs would improve their health outcomes, but 30.4% were neutral in their beliefs. Eighty-five percent worried about side effects. When evaluating the role of health insurance and costs, 27.8% of respondents reported that insurance requirements frequently prevent access to SCD treatments and 41.1% reported cost of treatments often limits access to healthcare. Among those who reported no current DMT use, 50% of them believe there is not enough information about DMTs. Lastly, among those who report currently taking a DMT, 42% of participants were negative or neutral in their belief that their current state of health depends on the use of DMTs.

Conclusions

A high percentage of participants report having a good understanding of DMTs; however, many still believe they need more information about DMTs. In fact, half of respondents who do not take a DMT believe there is not enough information about these medications. Even among those who currently take a DMT, nearly half do not explicitly agree that their current health depends on the use of DMTs. Overall, our study population may represent a subset of relatively high functioning individuals, given their enrollment in an insurance plan, access to a PCP and a hematologist, regular follow-up with a physician, and current use of a DMT. Yet in spite of its relatively privileged socioeconomic status, our study population experiences significant barriers to DMT use including deficits in information and understanding the role of DMTs. Future studies should capture outcomes across a diverse population with respect to socioeconomic variables, insurance status and DMT use. Interventions should be developed to better educate individuals with SCD on DMTs, particularly as newer pharmacological approaches are being developed and are likely to profoundly impact the management of SCD.

Kane-Gill:NIDDK: Research Funding; NCCIH: Research Funding; Society of Critical Care medicine: Membership on an entity's Board of Directors or advisory committees.