title: Improved hydroxyurea effect with the use of text messaging in children with sickle cell anemia.
abstract: BACKGROUND
  In children with sickle cell anemia (SCA), hydroxyurea reduces morbidity, but adherence is frequently suboptimal. Because most families of children with SCA have access to cellular telephone services, we assessed the impact of text messaged reminders as a tool to improve adherence to hydroxyurea.
  
  
  METHODS
  All patients <19 years of age with HbSS or HbSβ(0) thalassemia who were treated with hydroxyurea at a maximal tolerated dosage (MTD) at St. Jude Children's Research Hospital Comprehensive Pediatric Sickle Cell Program and who received automated text message reminders (SIMON®) were retrospectively identified. Laboratory parameters, hospitalizations, and medication possession ratios (MPR) prior to and after initiation of SIMON® were compared to assess the impact of SIMON®.
  
  
  RESULTS
  Of the 97.3% of families with access to a cell phone, 91% elected to receive text message reminders. Among 55 children receiving hydroxyurea at MTD, laboratory parameters reflected waning medication compliance during the 12 months prior to SIMON®. Following initiation of SIMON®, children had higher mean corpuscular volumes, hemoglobin levels and fetal hemoglobin percentages and lower absolute reticulocyte counts and bilirubin levels, suggesting improved medication adherence. Hospitalizations were uncommon before and after SIMON®, and medication possession ratios (MPRs) were high before and after SIMON®, neither was significantly changed.
  
  
  CONCLUSIONS
  SIMON® was feasible and improved hematologic parameters in children with SCA receiving hydroxyurea at a MTD. Future work will include extension of this technology to children with other chronic medical conditions who require daily use of medication.
authors.affiliation: Departments of Hematology, St. Jude Children's Research Hospital, Memphis, Tennessee.
authors.forename: Jeremie H
authors.initials: JH
authors.lastname: Estepp
authors.forename: Bryan
authors.initials: B
authors.lastname: Winter
authors.forename: Margery
authors.initials: M
authors.lastname: Johnson
authors.forename: Matthew P
authors.initials: MP
authors.lastname: Smeltzer
authors.forename: Scott C
authors.initials: SC
authors.lastname: Howard
authors.forename: Jane S
authors.initials: JS
authors.lastname: Hankins
mesh_terms: D000293:Adolescent; D000755:Anemia, Sickle Cell / Q000188:drug therapy*; D040421:Cell Phone; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D006918:Hydroxyurea / Q000627:therapeutic use*; D008297:Male; D020714:Maximum Tolerated Dose; D055118:Medication Adherence; D012189:Retrospective Studies
chemical_list: D006918:Hydroxyurea
keywords: medication adherence; sickle cell anemia; text messages