Global Treatment Satisfaction Levels and Treatment Patterns from the International Sickle Cell World Assessment Survey (SWAY): Hydroxyurea (HU) Versus No HU

Background: SWAY was a cross-sectional survey that assessed the global impact and treatment of sickle cell disease (SCD) (James et al. ASH 2019). SCD puts patients at risk of multiple complications driven by vaso-occlusion and hemolytic anemia. Vaso-occlusive crises (VOCs) are the hallmark of SCD and can require healthcare attention. VOC frequency may be reduced by HU (Charache et al. N Engl J Med 1995).

Aims: We assessed self-reported symptoms and quality of life (QoL) indicators for patients who reported using HU at the time of SWAY versus patients who did not, and we collected data on all treatments reported by SCD patients, by geographical region. Data were also collected regarding historical patient-reported use of HU prior to SWAY but these are not included here.

Methods: SWAY was completed between April and October 2019 by SCD patients from 16 countries across 6 regions. A limitation is that Asia and South America were represented by single countries (India and Brazil, respectively). SWAY was completed by proxy (parent/guardian/caregiver) for patients aged 6–11 years and could be optionally self-completed by patients aged ≥12 years. Opinions were captured using a 1–7 Likert scale for some questions (5–7 indicated high satisfaction/impact/agreement). SWAY did not assess treatment outcomes.

Results: Of 2145 patients, 652 (30%) reported receiving HU at the time of SWAY (56% female; 50% aged 6–25 years); 1493 patients reported not receiving HU at the time of SWAY (51% female; 59% aged 6–25 years). The number of patients reporting HU use varied regionally (Table). Patients who reported using HU also reported a lower VOC burden than patients who did not report using HU at the time of SWAY (median: 3 vs 4 VOCs in the 12 months before SWAY, respectively). However, considering other symptoms commonly experienced in the month prior to SWAY, a greater proportion of patients who reported using HU experienced these symptoms than patients who did not report using HU, except for headache and poor appetite, which were experienced by a lower proportion of patients who reported HU use (Figure). Similar proportions of patients reported that SCD had a high impact (Likert scale 5–7) on emotional wellbeing (61% [reported HU use at time of SWAY] vs 59% [did not report HU use at time of SWAY]) and daily activities (39% vs 40%, respectively).

Overall, when including dietary supplements, the most common treatment reported at the time of SWAY in all regions except the Middle East was folic acid. Common treatments varied regionally when excluding supplements (Table). Top treatment goals for patients in all regions were to improve QoL and prevent SCD worsening. Treatment satisfaction (range: 57–92%) was highest in Asia (Table). Over 70% of patients wanted alternatives to their ongoing pain medications in all regions, except Asia (44%).

Discussion: The proportion of patients reporting HU use at the time of SWAY was variable, but relatively low; HU was not in the top 3 treatments for Africa, Europe or North America. HU use was lowest in Africa, where no patients reported receiving HU at the time of the survey, which probably reflects high relative cost and poor access. Our regional analysis showed that many patients take supplements, such as folic acid, rather than HU. This may be indicative of limited alternatives to HU and reflects the differing global costs and availability of both medication and monitoring blood tests. Low reported use of HU may also reflect patients’ concerns about side effects or reluctance to take daily medication. It should be noted that some patients may be familiar with ‘hydroxycarbamide’ as a name for HU and might not have recognized the term ‘hydroxyurea’ on the survey. Data from SWAY were not validated by medical records and depended on patients’ recall.

Patients reporting HU use at the time of SWAY had a lower VOC burden than patients not reporting HU use. QoL indicators were similar for the 2 groups, but the overall symptom burden was higher for patients who reported HU use compared with those who did not. However, the 2 groups were not matched for pre-treatment disease burden and no information was collected regarding adherence or duration of previous HU use. Overall, although many patients reported treatment satisfaction, many wanted alternative pain management therapies. A wider range of treatment options are needed to reduce SCD symptoms and improve QoL, ultimately helping patients achieve their treatment goals.