title: Leveraging administrative data to monitor rituximab use in 2875 patients at 42 freestanding children's hospitals across the United States.
abstract: OBJECTIVE
  To describe the pharmacoepidemiology of rituximab use in children and to estimate the frequency of infectious events within a 1-year period after rituximab exposure.
  
  
  METHODS
  This is a retrospective cohort study of patients who received rituximab at 1 of 42 children's hospitals contributing data to the Pediatric Health Information System between January 1999 and June 2011. International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) discharge diagnosis codes were analyzed to categorize underlying diseases (hematologic malignancies, primary immunodeficiencies, autoimmune diseases, and transplant recipients) and to estimate inpatient infectious complication rates within each category.
  
  
  RESULTS
  A total of 2875 patients with 4639 rituximab admissions were identified. The median age at index admission was 11 years (IQR, 5-15 years). The rate of rituximab admissions increased from 3 to 185 per 100,000 admissions per year over the study interval. During the 1-year follow-up period, 463 patients (16%) died. Infectious events were assessed in 2246 of the rituximab-exposed patients; 6.1% were diagnosed with sepsis and 2.0% with septic shock. The frequency of sepsis ranged from 2.4% in patients with autoimmune diseases to 12.2% in those with primary immunodeficiencies. Three patients were assigned an ICD-9-CM discharge diagnosis code for Pneumocystis joroveci pneumonia, 1 patient was assigned an ICD-9-CM discharge diagnosis code for hepatitis B, and 1 patient was assigned an ICD-9-CM discharge diagnosis code for progressive multifocal leukoencephalopathy.
  
  
  CONCLUSIONS
  The use of rituximab has increased significantly in children with a variety of underlying diseases. Based on ICD-9-CM code data, the rates of sepsis and other life-threatening infections after rituximab exposure vary depending on the underlying condition. Based on surveillance of infection using ICD-9-CM diagnosis codes, the rates of opportunistic infections appear to be low.
authors.affiliation: Division of Oncology, Center for Pediatric Clinical Effectiveness, The Children's Hospital of Philadelphia, and Department of Pediatrics, Center for Clinical Epidemiology and Biostatistics, University of Pennsylvania School of Medicine, Philadelphia, PA 19104, USA. kavcicm@email.chop.edu
authors.forename: Marko
authors.initials: M
authors.lastname: Kavcic
authors.forename: Brian T
authors.initials: BT
authors.lastname: Fisher
authors.forename: Alix E
authors.initials: AE
authors.lastname: Seif
authors.forename: Yimei
authors.initials: Y
authors.lastname: Li
authors.forename: Yuan-Shung
authors.initials: YS
authors.lastname: Huang
authors.forename: Dana
authors.initials: D
authors.lastname: Walker
authors.forename: Richard
authors.initials: R
authors.lastname: Aplenc
mesh_terms: D000293:Adolescent; D058846:Antibodies, Monoclonal, Murine-Derived / Q000008:administration & dosage* / Q000009:adverse effects*; D002648:Child; D002675:Child, Preschool; D015331:Cohort Studies; D004363:Drug Utilization; D005260:Female; D006776:Hospitals, Pediatric; D006801:Humans; D038801:International Classification of Diseases; D008297:Male; D012189:Retrospective Studies; D000069283:Rituximab; D018805:Sepsis / Q000145:classification / Q000453:epidemiology* / Q000209:etiology; D016896:Treatment Outcome; D014481:United States
chemical_list: D058846:Antibodies, Monoclonal, Murine-Derived; D000069283:Rituximab