title: National trends in incidence rates of hospitalization for stroke in children with sickle cell disease.
abstract: BACKGROUND
  The success of primary stroke prevention for children with sickle cell disease (SCD) throughout the United States is unknown. Therefore, we aimed to generate national incidence rates of hospitalization for stroke in children with sickle cell disease (SCD) before and after publication of the Stroke Prevention Trial in Sickle Cell Anemia (STOP trial) in 1998.
  
  
  METHODS
  We performed a retrospective trend analysis of the 1993-2009 Nationwide Inpatient Sample and Kids' Inpatient Databases. Hospitalizations for SCD patients 0-18 years old with stroke were identified by ICD-9CM code. The primary outcome, the trend in annual incidence rate of hospitalization for stroke in children with SCD, was analyzed by linear regression. Incidence rates of hospitalization for stroke before and after 1998 were compared by the Wilcoxon rank-sum test.
  
  
  RESULTS
  From 1993 to 2009, 2,024 hospitalizations were identified for stroke. Using the mean annual incidence rate of hospitalization for stroke from 1993 to 1998 as the baseline, the rate decreased from 1993 to 2009 (point estimate = -0.022/100 patient years [95% CI, -0.039, -0.005], P = 0.027). The mean annual incidence rate of hospitalization stroke decreased by 45% from 0.51 per 100 patient years in 1993-1998 to 0.28 per 100 patient years in 1999-2009 (P = 0.008). Total hospital days and charges attributed to stroke also decreased by 45% and 24%, respectively.
  
  
  CONCLUSIONS
  After publication of the STOP trial and hydroxyurea licensure in 1998, the incidence of hospitalization for stroke in children with SCD decreased across the United States, suggesting that primary stroke prevention has been effective nationwide, but opportunity for improvement remains.
authors.affiliation: Division of Pediatric Hematology-Oncology, University of Texas Southwestern Medical Center at Dallas, Dallas, Texas 75390-9063, USA. tim.mccavit@childrens.com
authors.forename: Timothy L
authors.initials: TL
authors.lastname: McCavit
authors.forename: Lei
authors.initials: L
authors.lastname: Xuan
authors.forename: Song
authors.initials: S
authors.lastname: Zhang
authors.forename: Glenn
authors.initials: G
authors.lastname: Flores
authors.forename: Charles T
authors.initials: CT
authors.lastname: Quinn
mesh_terms: D000293:Adolescent; D000755:Anemia, Sickle Cell / Q000150:complications / Q000453:epidemiology*; D002648:Child; D002675:Child, Preschool; D016208:Databases, Factual; D005260:Female; D006760:Hospitalization / Q000706:statistics & numerical data* / Q000639:trends; D006801:Humans; D015994:Incidence; D008297:Male; D012189:Retrospective Studies; D012307:Risk Factors; D020521:Stroke / Q000453:epidemiology* / Q000209:etiology / Q000517:prevention & control; D014481:United States / Q000453:epidemiology