An Age Analysis of the International Sickle Cell World Assessment Survey (SWAY), Focusing on Symptoms, Treatment Goals and the Impact of SCD on Patients’ Daily Lives

Background: Sickle cell disease (SCD) is associated with many clinical complications, with vaso-occlusive crises (VOCs) being a hallmark of the disease. SCD-related complications are largely driven by vaso-occlusion and hemolytic anemia, and can lead to end-organ damage and early death. Analyses of SWAY, a cross-sectional survey, highlighted a substantial global impact of SCD on patients’ quality of life (QoL) (James et al. ASH 2019; Osunkwo et al. ASH 2019). However, understanding how the burden of disease differs for pts of different ages could help improve management of SCD over a pt’s lifespan.

Aim: To assess, using data from SWAY, whether symptoms (excluding VOCs, as previously analyzed by Osunkwo et al. EHA 2020), treatment goals and the perceived impact of SCD were different for pts of different ages.

Methods: Between April and October 2019, 2145 SCD pts aged ≥6 years participated in SWAY. The survey was completed by proxy (parent/caregiver/guardian) for pts aged 6–11 years and could be optionally self-completed by pts aged ≥12 years. Opinions were captured using a 1–7 Likert scale for some questions (5–7 indicated high satisfaction/impact/agreement). SWAY was not designed to assess treatment outcomes; all analyses are descriptive. Age groups were not matched and pts were not followed over time.

Results: To understand how the most dominant symptoms of SCD differ for pts of different ages, the top 5 most commonly reported symptoms, stratified by age, were analyzed (Figure 1). Fatigue and bone aches were consistently reported, and the proportion of pts reporting them trended towards increasing with age. Furthermore, when asked which symptoms they most wanted to be resolved, fatigue was ranked in the top 3 by 40.7% of pts. Anxiety was a dominant symptom for pts aged 19–25, 36–45 and 46–50 years, whereas low mood was a dominant symptom for pts aged 19–50 and ≥60 years. Poor appetite was a dominant symptom for pts aged 6–16 years. Breathing issues were a dominant symptom for pts aged 6–18, 46–50 and ≥60 years, whereas vision issues were a dominant symptom for pts aged 51–59 years only. Insomnia was dominant for pts aged 46–50.

The treatment goals that pts ranked as the most important were similar across age groups. Pts consistently included improving QoL, preventing worsening of SCD, reducing the number of VOCs and improving overall symptoms in their top 3, although the proportions of pts reporting these varied across age groups (Figure 2). Unsurprisingly, 23.0% of pts aged 12–16 years ranked increasing the ability to attend school in their top 3 goals. For pts aged 46–50 and 51–59 years, 27.5% and 20.7%, respectively, ranked reducing fatigue in their top 3 treatment goals.

The highest proportions of pts reporting a high impact of SCD on their emotional wellbeing were aged 46–50 years (74.5%) and ≥60 years (73.9%), compared with 59.6% of all pts. Similarly, the highest proportions of pts reporting a high impact of SCD on daily activities were aged 46–50 years (51.0%) and ≥60 years (60.9%), compared with 38.1% of all pts.

Limitations: These findings are based on pt and proxy reports, with potential parental bias being introduced for pediatric patients. There were variations in sample sizes, which was most noticeable for patients aged ≥46 years.

Discussion: Fatigue and bone aches were consistently reported as dominant symptoms for all ages. Other dominant symptoms that were not consistent across age groups were anxiety, low mood, poor appetite, breathing issues and vision issues. In addition to the 36–45 years and 46–50 years groups, anxiety was a dominant symptom for pts aged 19–25 years. Along with other changes that could occur at this age, a recent transition from pediatric to adult care may contribute to anxiety being a dominant symptom; however, any direct relationship between anxiety and transitioning between care systems requires further investigation. The consistent reporting of low mood among adults, but not pediatrics, may reflect the increasing burden of disease that occurs with age. This is supported by higher proportions of pts aged ≥46 years versus <45 years reporting a high impact on emotional wellbeing and daily life.

Improving QoL was consistently ranked the most important treatment goal for pts. This emphasizes, from the pt’s perspective, the need for further improvements in the management of SCD.