Trends in blood transfusion, hydroxyurea use, and iron overload among children with sickle cell disease enrolled in Medicaid, 2004-2019.

BACKGROUND: There have been significant changes in clinical guidelines for sickle cell disease (SCD) over the past two decades, including updated indications for hydroxyurea, transfusions, and iron overload management. In practice however, there are few studies that examine SCD care utilization over time. METHODS: We conducted a serial cross-sectional cohort study of pediatric SCD patients from 2004 to 2019 using Georgia Medicaid claims data. For each year, we reported receipt of any transfusion, chronic transfusion, or three or more filled hydroxyurea prescriptions. For children receiving chronic transfusion (six or more annual transfusions), we evaluated iron overload diagnosis, monitoring, and chelation use. Among children with sickle cell anemia (SCA), we examined rates of transfusions and hydroxyurea use. The Cochran-Armitage test was used to assess trend. RESULTS: There were 5316 unique children 2-18 years old with SCD enrolled in Georgia Medicaid from 2004 to 2019. Children receiving any transfusion increased from 2004 to 2010, then stabilized. In SCA patients, chronic transfusions initially increased from 2004 to 2010, then stabilized from 2010 to 2019. For chronically transfused children, monitoring of iron burden and filled chelator prescriptions both increased significantly. Hydroxyurea use in SCA patients increased from 12% to 37%, with increases noted within each age group, most notably from 21% to 60% in the 13-18-year-old cohort. CONCLUSION: We demonstrated changes in SCD care utilization over time, including increased hydroxyurea use, changes in transfusion rates, and increased attention to iron overload management. While trends in clinical management do follow updates in treatment guidelines, there is still delayed and suboptimal uptake of guideline recommendations in pediatric SCD patients.

Influenza vaccine effectiveness and disease burden in children and adolescents with sickle cell disease: 2012-2017.

BACKGROUND: Data are limited on the burden of influenza and seasonal influenza vaccine effectiveness (VE) in children with sickle cell disease (SCD). METHODS: We used a prospectively collected clinical registry of SCD patients 6 months to 21 years of age to determine the influenza cases per 100 patient-years, vaccination rates, and a test-negative case-control study design to estimate influenza VE against medically attended laboratory-confirmed influenza infection. Influenza-positive cases were randomly matched to test-negative controls on age and influenza season in 1:1 ratio. We used adjusted logistic regression models to compare odds ratio (OR) of vaccination in cases to controls. We calculated VE as [100% × (1 - adjusted OR)] and computed 95% confidence intervals (CIs) around the estimate. RESULTS: There were 1037 children with SCD who were tested for influenza, 307 children (29.6%) had at least one influenza infection (338 infections, incidence rate 3.7 per 100 person-years; 95% CI, 3.4-4.1) and 56.2% of those tested received annual influenza vaccine. Overall VE pooled over five seasons was 22.3% (95% CI, -7.3% to 43.7%). Adjusted VE estimates ranged from 39.7% (95% CI, -70.1% to 78.6%) in 2015/2016 to -5.9% (95% CI, -88.4% to 40.4%) in the 2016/17 seasons. Influenza VE varied by age and was highest in children 1-5 years of age (66.6%; 95% CI, 30.3-84.0). Adjusted VE against acute chest syndrome during influenza infection was 39.4% (95% CI, -113.0 to 82.8%). CONCLUSIONS: Influenza VE in patients with SCD varies by season and age. Multicenter prospective studies are needed to better establish and monitor influenza VE among children with SCD.