Impact of adherence to hydroxyurea on health outcomes among patients with sickle cell disease

Abstract

Although new pharmaceutical therapy options have recently become available, hydroxyurea is still the most commonly used and affordable treatment option for sickle cell disease (SCD). This study aimed to update the evidence on hydroxyurea adherence and its association with clinical and economic outcomes among individuals with SCD. This retrospective study used Texas Medicaid claims data from 09/2011–08/2016. Individuals were included if they had ≥1 inpatient or ≥2 outpatient SCD diagnoses, had ≥1 hydroxyurea prescription, were 2–63 years of age, and were continuously enrolled in Texas Medicaid between 6 months before and 1 year after the first hydroxyurea prescription fill date (index date). Hydroxyurea adherence (Medication Possession Ratio; MPR), vaso‐occlusive crisis (VOC)‐related outcomes, healthcare utilization and expenditures (SCD‐related and all‐cause) during the 1 year following the index date were measured. Bivariate and multivariable analyses were used to address the study objectives. Among 1035 included individuals (age: 18.8 ± 12.5 years, female: 52.1%), 20.9% were adherent to hydroxyurea (defined as MPR≥0.8). After adjustment for demographic and clinical characteristics, compared to being non‐adherent, adhering to hydroxyurea was significantly associated with: a lower risk (Odds Ratio [OR] = 0.480, p = .0007) and hazard rate (Hazard Ratio [HR] = 0.748, p = .0005) of a VOC event, fewer VOC events (Incidence Rate Ratio [IRR] = 0.767, p = .0009), fewer VOC‐related hospital days (IRR = 0.593, p = .0003), fewer all‐cause and SCD‐related hospitalizations (IRR = 0.712, p = .0008; IRR = 0.707, p = .0008, respectively) and emergency department visits (IRR = 0.768, p = .0037; IRR = 0.746, p = .0041, respectively), and lower SCD‐related total healthcare expenditures (IRR = 0.796, p = .0266). Efforts to increase adherence to hydroxyurea could improve clinical and economic outcomes among individuals with SCD.

Understanding patient-related barriers to hydroxyurea use among adolescent and adult patients with sickle cell disease in Mulago and Kiruddu hospitals, Uganda, a qualitative study

“…With greater use of HU for eligible patients, it is expected that fewer patients will be hospitalized for complications of SCD, resulting in a net reduction of national healthcare costs for patients with SCD [ 9 ]. In addition, the broader appropriate use of HU in patients with SCD should improve their quality of life and productivity [ 9 ].…”

“…With greater use of HU for eligible patients, it is expected that fewer patients will be hospitalized for complications of SCD, resulting in a net reduction of national healthcare costs for patients with SCD [ 9 ]. In addition, the broader appropriate use of HU in patients with SCD should improve their quality of life and productivity [ 9 ]. With this information, we can lobby the government and/or donors to avail recourses for continued supply of HU and other resources like laboratory capacity that aid us in giving comprehensive care to patients with SCD.…”

Population characterization of mutations for sickle cell anemia and its treatment: One step towards personalized medicine for the disease

“…Principalmente, los niveles de HF son cruciales para determinar la gravedad de la ACF 9,10 . La identificación de los SNPs es un avance en el desarrollo de la medicina personalizada, específicamente en la ACF, donde recientemente se ha destacado la importancia de los modificadores genéticos de la variabilidad 11,12 .…”