title: Randomised trial of a parent-mediated intervention for infants at high risk for autism: longitudinal outcomes to age 3 years.
abstract: BACKGROUND
  There has been increasing interest in the potential for pre-emptive interventions in the prodrome of autism, but little investigation as to their effect.
  
  
  METHODS
  A two-site, two-arm assessor-blinded randomised controlled trial (RCT) of a 12-session parent-mediated social communication intervention delivered between 9 and 14 months of age (Intervention in the British Autism Study of Infant Siblings-Video Interaction for Promoting Positive Parenting), against no intervention. Fifty-four infants (28 intervention, 26 nonintervention) at familial risk of autism but not otherwise selected for developmental atypicality were assessed at 9-month baseline, 15-month treatment endpoint, and 27- and 39-month follow-up.
  
  
  METHODS
  severity of autism prodromal symptoms, blind-rated on Autism Observation Schedule for Infants or Autism Diagnostic Observation Schedule 2nd Edition across the four assessment points.
  
  
  RESULTS
  blind-rated parent-child interaction and child language; nonblind parent-rated communication and socialisation. Prespecified intention-to-treat analysis combined estimates from repeated measures within correlated regressions to estimate the overall effect of the infancy intervention over time.
  
  
  RESULTS
  Effect estimates in favour of intervention on autism prodromal symptoms, maximal at 27 months, had confidence intervals (CIs) at each separate time point including the null, but showed a significant overall effect over the course of the intervention and follow-up period (effect size [ES] = 0.32; 95% CI 0.04, 0.60; p = .026). Effects on proximal intervention targets of parent nondirectiveness/synchrony (ES = 0.33; CI 0.04, 0.63; p = .013) and child attentiveness/communication initiation (ES = 0.36; 95% CI 0.04, 0.68; p = .015) showed similar results. There was no effect on categorical diagnostic outcome or formal language measures.
  
  
  CONCLUSIONS
  Follow-up to 3 years of the first RCT of a very early social communication intervention for infants at familial risk of developing autism has shown a treatment effect, extending 24 months after intervention end, to reduce the overall severity of autism prodromal symptoms and enhance parent-child dyadic social communication over this period. We highlight the value of extended follow-up and repeat assessment for early intervention trials.
authors.affiliation: Social Development Research Group, School of Biological Sciences, University of Manchester, Manchester, UK.|Royal Manchester Children's Hospital, Manchester, UK.
authors.forename: Jonathan
authors.initials: J
authors.lastname: Green
authors.affiliation: Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK.|National Institute for Health Research Medical Health Biomedical Research Centre, South London and Maudsley NHS Foundation Trust, London, UK.
authors.forename: Andrew
authors.initials: A
authors.lastname: Pickles
authors.affiliation: Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK.|Centre for Brain and Cognitive Development, Birkbeck College, London, UK.
authors.forename: Greg
authors.initials: G
authors.lastname: Pasco
authors.affiliation: Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK.
authors.forename: Rachael
authors.initials: R
authors.lastname: Bedford
authors.affiliation: School of Health Sciences, University of Manchester, Manchester, UK.
authors.forename: Ming Wai
authors.initials: MW
authors.lastname: Wan
authors.affiliation: Centre for Brain and Cognitive Development, Birkbeck College, London, UK.|Department of Psychiatry, McGill University, West Montréal, QC, Canada.
authors.forename: Mayada
authors.initials: M
authors.lastname: Elsabbagh
authors.affiliation: Evelina London Children's Hospital and King's College London Neurosciences Centre, London, UK.
authors.forename: Vicky
authors.initials: V
authors.lastname: Slonims
authors.affiliation: Centre for Brain and Cognitive Development, Birkbeck College, London, UK.
authors.forename: Teea
authors.initials: T
authors.lastname: Gliga
authors.affiliation: Centre for Brain and Cognitive Development, Birkbeck College, London, UK.
authors.forename: Emily
authors.identifier: http://orcid.org/0000-0001-5747-9540
authors.initials: E
authors.lastname: Jones
authors.affiliation: Centre for Brain and Cognitive Development, Birkbeck College, London, UK.
authors.forename: Celeste
authors.initials: C
authors.lastname: Cheung
authors.affiliation: Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK.
authors.forename: Tony
authors.initials: T
authors.lastname: Charman
authors.affiliation: Centre for Brain and Cognitive Development, Birkbeck College, London, UK.
authors.forename: Mark
authors.initials: M
authors.lastname: Johnson
mesh_terms: D000067877:Autism Spectrum Disorder / Q000517:prevention & control*; D002675:Child, Preschool; D003142:Communication; D018479:Early Intervention, Educational / Q000379:methods; D004505:Education, Nonprofessional; D005260:Female; D006801:Humans; D007398:Interpersonal Relations; D007804:Language Development; D008137:Longitudinal Studies; D008297:Male; D017063:Outcome Assessment, Health Care; D010287:Parent-Child Relations; D016487:Parenting; D062706:Prodromal Symptoms; D016037:Single-Blind Method
keywords: Pre-emptive intervention; autism; autism spectrum disorder; high-risk siblings; parent-mediated intervention; prevention trials