title: Screening for autism in pre-school children in primary care: systematic review of English Language tools.
abstract: OBJECTIVE
  To review the accuracy of brief screening tools for autism in pre-school children.
  
  
  METHODS
  Systematic review of diagnostic accuracy studies.
  
  
  METHODS
  Medline, Embase, Cinahl and Psychlit plus references of identified papers and contact with authors.
  
  
  METHODS
  Children and infants aged 5 years or less without a prior diagnosis of autism or pervasive development delay.
  
  
  METHODS
  Tools/checklists appropriate for use in screening for autism in primary care settings.
  
  
  METHODS
  Sensitivity, specificity, positive and negative predictive value of screening tools and likelihood ratios relative to a diagnostic assessment made using either DSM-III/IV or ICD 10 diagnosis.
  
  
  RESULTS
  Three studies considering two tools were identified. The CHecklist for Autism in Toddlers (CHAT) was tested on an appropriate population sample with moderate long-term follow-up but demonstrated poor sensitivity and positive predictive value. Weaker evidence suggested that the Modified CHecklist for Autism in Toddlers (M-CHAT) had high sensitivity but follow-up was of shorter term and less comprehensive.
  
  
  CONCLUSIONS
  The CHAT demonstrated a level of sensitivity unlikely to be useful for population screening purposes, however, its high specificity suggests it has utility in secondary screening. The M-CHAT is a parent only report and might be more sensitive, and therefore appropriate for population screening. However, full conclusions regarding its accuracy cannot be drawn until follow-up data has been collected.
authors.affiliation: Health Visitor, Westminster Primary Care Trust, 158 Herne Hill Road, London SE24 0AH, UK. elizabeth.mawle@westminster-pct.nhs.uk
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Mawle
authors.forename: Peter
authors.initials: P
authors.lastname: Griffiths
mesh_terms: D000367:Age Factors; D001321:Autistic Disorder / Q000175:diagnosis*; D002675:Child, Preschool; D042241:Early Diagnosis; D018479:Early Intervention, Educational; D019317:Evidence-Based Medicine; D005500:Follow-Up Studies; D006801:Humans; D007223:Infant; D016013:Likelihood Functions; D008403:Mass Screening / Q000379:methods* / Q000592:standards; D010290:Parents / Q000523:psychology; D011320:Primary Health Care / Q000379:methods* / Q000592:standards; D015203:Reproducibility of Results; D012107:Research Design; D012680:Sensitivity and Specificity; D016037:Single-Blind Method