Risk of vaso-occlusive crisis requiring hospitalization in sickle cell disease patients in Brazil: retrospective cohort study of real-world data

Background: Sickle cell disease (SCD) is associated with several complications, high health-care-related costs and reduced life expectancy. This study addresses the high incidence of vaso-occlusive crises (VOC) in patients with SCD in Brazil, a condition that significantly impacts public health and healthcare costs. Objective: To describe clinical characteristics, healthcare resource utilization, incidence risk, and complications due to VOCs requiring hospitalization among Brazilian patients with SCD. Methods: Between January 2016 to December 2018, we involved 404 SCD patients aged 5-67, we utilized routinely collected data from four referral centers in Brazil. We characterized the cohort regarding healthcare resource utilization (disease complications, mortality, pharmacological treatments, blood transfusions, laboratory and imaging tests, emergency department visits, hospitalizations, and surgeries). Results: Of the 404 participants, 312 (77%) were aged ≥18 and 228 (56%) were female. The most common genotype was HbSS (n=289, 72%). At baseline, 66.6% used hydroxyurea; osteonecrosis was the most prevalent SCD complication (82 patients, 21%). During the 3-year follow-up, 240 (59.4%, 95% confidence interval [95% CI], 55 to 64%) of the 404 participants developed VOCs requiring hospitalization. The incidence rate was 812 events per 1000 person-years (95 CI: 758 to 869). Overall, the cohort was associated with considerable healthcare utilization regarding pharmacological treatments, blood transfusions, laboratory and imaging tests, emergency department visits, and hospitalizations. Conclusion: SCD continues to cause substantial morbidity and utilization of the Brazilian healthcare system. New strategies and therapies are needed to prevent VOCs and improve clinical outcomes, thereby reducing VOC-related healthcare utilization in Brazil.