title: Systematic evidence review of newborn screening and treatment of severe combined immunodeficiency.
abstract: BACKGROUND
  Severe combined immunodeficiency (SCID) is a group of disorders that leads to early childhood death as a result of severe infections. Recent research has addressed potential newborn screening for SCID.
  
  
  OBJECTIVE
  To conduct a systematic review of the evidence for newborn screening for SCID, including test characteristics, treatment efficacy, and cost-effectiveness.
  
  
  METHODS
  We searched Medline and the OVID In-Process & Other Non-Indexed Citations databases. We excluded articles if they were reviews, editorials or other opinion pieces, or case series of fewer than 4 patients or if they contained only adult subjects or nonhuman data. The remaining articles were systematically evaluated, and data were abstracted by 2 independent reviewers using standardized tools. For topics that lacked published evidence, we interviewed experts in the field.
  
  
  RESULTS
  The initial search resulted in 719 articles. Twenty-six met inclusion criteria. The results of several small studies suggested that screening for SCID is possible. Interviews revealed that 2 states have begun pilot screening programs. Evidence from large case series indicates that children receiving early stem-cell transplant for SCID have improved outcomes compared with children who were treated later. There is some inconclusive evidence regarding the need for donor-recipient matching and use of pretransplant chemotherapy. Few data on the cost-effectiveness of a SCID-screening program.
  
  
  CONCLUSIONS
  Evidence indicates the benefits of early treatment of SCID and the possibility of population-based newborn screening. Better information on optimal treatment and the costs of treatment and screening would benefit policy makers deciding among competing health care priorities.
authors.affiliation: Center for Child and Adolescent Health Policy, Mass General Hospital for Children, Boston, Massachusetts, USA. ellen.lipstein@cchmc.org
authors.forename: Ellen A
authors.initials: EA
authors.lastname: Lipstein
authors.forename: Sienna
authors.initials: S
authors.lastname: Vorono
authors.forename: Marsha F
authors.initials: MF
authors.lastname: Browning
authors.forename: Nancy S
authors.initials: NS
authors.lastname: Green
authors.forename: Alex R
authors.initials: AR
authors.lastname: Kemper
authors.forename: Alixandra A
authors.initials: AA
authors.lastname: Knapp
authors.forename: Lisa A
authors.initials: LA
authors.lastname: Prosser
authors.forename: James M
authors.initials: JM
authors.lastname: Perrin
mesh_terms: D016026:Bone Marrow Transplantation / Q000191:economics; D002648:Child; D002675:Child, Preschool; D003362:Cost-Benefit Analysis; D019317:Evidence-Based Medicine / Q000191:economics; D005260:Female; D006291:Health Policy / Q000191:economics; D006292:Health Priorities / Q000191:economics; D006650:Histocompatibility Testing; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D015997:Neonatal Screening / Q000191:economics; D016511:Severe Combined Immunodeficiency / Q000175:diagnosis* / Q000191:economics / Q000401:mortality / Q000628:therapy; D015996:Survival Rate; D016896:Treatment Outcome; D014481:United States