High hydroxyurea usage in sickle cell anemia regardless of patient demographics.

Hydroxyurea is highly effective in sickle cell disease, but it is still underutilized. Reports of hydroxyurea utilization largely use Medicaid data, and socioeconomics is often cited as a barrier. To address whether patient demographics influenced the high hydroxyurea usage rate recently reported for the pediatric sickle cell program of Northern Virginia, analysis of data from 2011 to 2021 revealed no statistical difference in hydroxyurea usage rate between Medicaid and non-Medicaid, African American and African, or age less than 13 and age greater than or equal to 13 years cohorts, demonstrating that hydroxyurea can be successfully implemented across demographic groups.

Ten-year longitudinal analysis of hydroxyurea implementation in a pediatric sickle cell program.

Hydroxyurea (HU) has proven benefit in sickle cell anemia (SCA), but HU is still underutilized. The Pediatric Sickle Cell Program of Northern Virginia prescribes HU regardless of symptoms to all SCA patients age ≥ 9 months and prospectively tracks outcomes. HU is dosed to maximum tolerated dosing (MTD), targeting 30% Hgb F. Longitudinal data from 2009 to 2019 encompassing 1222 HU-eligible and 950 HU-exposure patient-years were analyzed in 2-year intervals for hemoglobin (Hgb), fetal hemoglobin (Hgb F), hospitalizations, transfusions, and treat-and-release ED visits. Comparing HU-eligible patients in the interval prior to HU implementation (2009-2011) to the last interval analyzed after HU implementation (2017-2019), HU usage increased from 33% to 93%, average Hgb increased from 8.3 ± 0.98 to 9.8 ± 1.3 g/dl (p < .0001), average Hgb F rose from 13 ± 8.7% to 26 ± 9.9% (p < .0001), hospitalizations decreased from 0.71 (95% CI 0.54-0.91) to 0.2 (95% CI 0.13-0.28) admissions/person-year, sporadic transfusions decreased from 0.4 (95% CI 0.27-0.55) to 0.05 (95% CI 0.02-0.12) transfusions/person-year. Treat-and-release ED visit rates remained unchanged, varying between 0.49 (95% CI 0.36-0.64) and 0.64 (95% CI 0.48-0.83) visits/person-year. By the last interval, 72% of patients had Hgb ≥ 9 g/dl, 42% had Hgb F ≥ 30%, 79% experienced no hospitalizations, and 94% received no transfusions. Uniform HU prescription for SCA patients with close monitoring to achieve high Hgb F resulted in significant improvements in laboratory and clinical outcomes within 2 years, which continued to improve over the next 6 years. Rigorous HU implementation in a pediatric sickle cell population is feasible, effective, and sustainable.

Prospective longitudinal follow-up of children with sickle cell disease treated with hydroxyurea since infancy.

BACKGROUND: Hydroxyurea (HU) increases fetal hemoglobin (HgbF) and ameliorates sickle cell disease (SCD) symptoms. Studies have demonstrated the safety and efficacy of HU in infants and children. Initiation of HU in infancy for children with SCD needs to be implemented in community practice. PROCEDURE: Starting in 2011, the Pediatric Sickle Cell Program of Northern Virginia initiated HU in infants with SCD. A prospective longitudinal database tracked the clinical course and outcomes. RESULTS: Twenty-four children with HgbSS who started HU by age 1 were continuously followed for a total of 95 person-years. Age at the time of analysis ranged from 2 to 7 years. Average hemoglobin at 6-month intervals ranged from 9.5 + 1.9 to 10.7 + 0.8 g/dL, and average HgbF ranged from 27.8 + 5.0% to 34.1 + 6.6%. Twenty-seven hospitalizations occurred (0.28/person-year), all before age 3, including 19 (70%) for fever or infection, five (19%) for splenic sequestration, and one (4%) for pain in an infant prior to starting HU. The treat-and-release emergency department visits totaled 68 (0.72/person-year), including 62 visits (91%) for fever, infection, or viral illness, and two visits (3%) for pain/dactylitis in infants before HU initiation. Splenic sequestration accounted for all five transfusions. No pain episodes requiring medical attention were documented after HU initiation. No complicated acute chest syndrome, no abnormal or conditional transcranial Doppler ultrasound, and no overt strokes occurred. CONCLUSION: Implementation of HU in infancy for patients with SCD in community practice is feasible and is highly effective in preventing disease complications.