title: Hospital admission rates for pediatric multiple sclerosis in the United States using the Pediatric Health Information System (PHIS).
abstract: BACKGROUND
  The onset of multiple sclerosis (MS) during childhood or adolescence is increasingly recognized in the United States. Administrative databases quantify healthcare utilization as measured by hospital admissions, providing insight into the impact of MS in the pediatric population.
  
  
  OBJECTIVE
  We examine the frequency of hospital admissions for pediatric MS in the US using the Pediatric Health Information System (PHIS) database.
  
  
  METHODS
  Data was extracted from the PHIS database using the ICD-9 code for MS (340.00) and reviewed to verify case ascertainment. Mean, median, and range values were determined for the number of inpatient hospitalizations per patient, number of days in the hospital, and cost of each encounter. A trend analysis was performed to evaluate the annual frequency of MS-related admissions over the study period.
  
  
  RESULTS
  After case verification, the PHIS database extraction reported 2068 hospital inpatient encounters for 1422 unique pediatric MS patients between 2004 and 2013. The median number of hospitalizations per patient was 2 with a median hospital stay of 4 days. Admission rates for MS increased from 2.37 per 10,000 in 2004 to 4.13 per 10,000 in 2013.
  
  
  CONCLUSIONS
  The number of admissions due to pediatric MS has increased since the start of the PHIS database collection, concurrent with increased disease awareness and the establishment of dedicated pediatric MS centers.
authors.affiliation: Children's Hospital of Philadelphia, Colket Translational Research Building, 10012, 3501 Civic Center Blvd, Philadelphia, PA 19104, United States. Electronic address: laverya@email.chop.edu.
authors.forename: Amy M
authors.initials: AM
authors.lastname: Lavery
authors.affiliation: Children's Hospital of Philadelphia, Colket Translational Research Building, 10012, 3501 Civic Center Blvd, Philadelphia, PA 19104, United States.
authors.forename: Brenda L
authors.initials: BL
authors.lastname: Banwell
authors.affiliation: Children's Hospital of Philadelphia, Colket Translational Research Building, 10012, 3501 Civic Center Blvd, Philadelphia, PA 19104, United States.
authors.forename: Geraldine
authors.initials: G
authors.lastname: Liu
authors.affiliation: Children's Hospital of Philadelphia, Colket Translational Research Building, 10012, 3501 Civic Center Blvd, Philadelphia, PA 19104, United States.
authors.forename: Amy T
authors.initials: AT
authors.lastname: Waldman
mesh_terms: D000293:Adolescent; D002648:Child; D016208:Databases, Factual; D005260:Female; D017048:Health Care Costs / Q000706:statistics & numerical data; D063005:Health Information Systems; D006760:Hospitalization / Q000191:economics / Q000706:statistics & numerical data*; D006776:Hospitals, Pediatric / Q000191:economics / Q000706:statistics & numerical data; D006801:Humans; D008297:Male; D009103:Multiple Sclerosis / Q000191:economics / Q000453:epidemiology* / Q000628:therapy*; D014481:United States / Q000453:epidemiology
keywords: Hospital admissions; Multiple sclerosis; Pediatric; Pediatric Health Information System