Effect of Preemptive Intervention on Developmental Outcomes Among Infants Showing Early Signs of Autism: A Randomized Clinical Trial of Outcomes to Diagnosis.

Importance: Intervention for individuals with autism spectrum disorder (ASD) typically commences after diagnosis. No trial of an intervention administered to infants before diagnosis has shown an effect on diagnostic outcomes to date. Objective: To determine the efficacy of a preemptive intervention for ASD beginning during the prodromal period. Design, Setting, and Participants: This 2-site, single rater-blinded randomized clinical trial of a preemptive intervention vs usual care was conducted at 2 Australian research centers (Perth, Melbourne). Community sampling was used to recruit 104 infants aged 9 to 14 months showing early behaviors associated with later ASD, as measured by the Social Attention and Communication Surveillance-Revised. Recruitment occurred from June 9, 2016, to March 30, 2018. Final follow-up data were collected on April 15, 2020. Interventions: Infants were randomized on a 1:1 ratio to receive either a preemptive intervention plus usual care or usual care only over a 5-month period. The preemptive intervention group received a 10-session social communication intervention, iBASIS-Video Interaction to Promote Positive Parenting (iBASIS-VIPP). Usual care comprised services delivered by community clinicians. Main Outcomes and Measures: Infants were assessed at baseline (approximate age, 12 months), treatment end point (approximate age, 18 months), age 2 years, and age 3 years. Primary outcome was the combined blinded measure of ASD behavior severity (the Autism Observation Scale for Infants and the Autism Diagnostic Observation Schedule, second edition) across the 4 assessment points. Secondary outcomes were an independent blinded clinical ASD diagnosis at age 3 years and measures of child development. Analyses were preregistered and comprised 1-tailed tests with an α level of .05. Results: Of 171 infants assessed for eligibility, 104 were randomized; 50 infants (mean [SD] chronological age, 12.40 [1.93] months; 38 boys [76.0%]) received the iBASIS-VIPP preemptive intervention plus usual care (1 infant was excluded after randomization), and 53 infants (mean [SD] age, 12.38 [2.02] months; 32 boys [60.4%]) received usual care only. A total of 89 participants (45 in the iBASIS-VIPP group and 44 in the usual care group) were reassessed at age 3 years. The iBASIS-VIPP intervention led to a reduction in ASD symptom severity (area between curves, -5.53; 95% CI, -∞ to -0.28; P = .04). Reduced odds of ASD classification at age 3 years was found in the iBASIS-VIPP group (3 of 45 participants [6.7%]) vs the usual care group (9 of 44 participants [20.5%]; odds ratio, 0.18; 95% CI, 0-0.68; P = .02). Number needed to treat to reduce ASD classification was 7.2 participants. Improvements in caregiver responsiveness and language outcomes were also observed in the iBASIS-VIPP group. Conclusions and Relevance: Receipt of a preemptive intervention for ASD from age 9 months among a sample of infants showing early signs of ASD led to reduced ASD symptom severity across early childhood and reduced the odds of an ASD diagnosis at age 3 years. Trial Registration: http://anzctr.org.au identifier: ACTRN12616000819426.

Pre-emptive intervention versus treatment as usual for infants showing early behavioural risk signs of autism spectrum disorder: a single-blind, randomised controlled trial.

BACKGROUND: Great interest exists in the potential efficacy of prediagnostic interventions within the autism spectrum disorder prodrome, but available evidence relates to children at high familial risk. We aimed to test the efficacy of a pre-emptive intervention designed for infants showing early behavioural signs of autism spectrum disorder. METHODS: In this single-blind, randomised controlled trial done at two specialist centres in Australia, infants aged 9-14 months were enrolled if they were showing at least three early behavioural signs of autism spectrum disorder on the Social Attention and Communication Surveillance-Revised (SACS-R) 12-month checklist. Infants were randomly assigned (1:1) to receive a parent-mediated video-aided intervention (iBASIS-VIPP) or treatment as usual. Group allocation was done by minimisation, stratified by site, sex, age, and the number of SACS-R risk behaviours. Assessments were done at baseline (before treatment allocation) and at the 6 month endpoint. The primary outcome was Autism Observation Scale for Infants (AOSI), which measures early behavioural signs associated with autism spectrum disorder. Secondary outcomes were a range of infant and caregiver outcomes measured by Manchester Assessment of Caregiver-Infant interaction (MACI), Mullen Scales of Early Learning (MSEL), Vineland Adaptive Behaviour Scales, 2nd edition (VABS-2), MacArthur-Bates Communicative Development Inventory (MCDI), and Parenting Sense of Competence (PSOC) scale. This trial is registered with Australian New Zealand Clinical Trials Registry, number ANZCTR12616000819426. FINDINGS: Between June 9, 2016, and March 30, 2018, 103 infants were randomly assigned, 50 to the iBASIS-VIPP group and 53 to the treatment-as-usual group. After the intervention, we observed no significant differences between groups on early autism spectrum disorder behavioural signs measured by the AOSI (difference estimate -0·74, 95% CI -2·47 to 0·98). We also observed no significant differences on secondary outcomes measuring caregiver non-directiveness (0·16, -0·33 to 0·65), caregiver sensitive responding (0·24, -0·15 to 0·63), and infant attentiveness (-0·19, -0·63 to 0·25) during parent-child interactions (MACI), as well as on researcher-administered measures of receptive (1·30, -0·48 to 3·08) and expressive language (0·54, -0·73 to 1·80), visual reception (0·31, -0·77 to 1·40), and fine motor skills (0·55, -0·32 to 1·41) using the MSEL. Compared with the treatment-as-usual group, the iBASIS-VIPP group had lower infant positive affect (-0·69, -1·27 to -0·10) on the MACI, but higher caregiver-reported receptive (37·17, 95% CI 10·59 to 63·75) and expressive vocabulary count (incidence rate ratio 2·31, 95% CI 1·22 to 4·33) on MCDI, and functional language use (difference estimate 6·43, 95% CI 1·06 to 11·81) on VABS. There were no significant group differences on caregiver-reported measures of MCDI infant gesture use (3·22, -0·60 to 7·04) and VABS social behaviour (3·28, -1·43 to 7·99). We observed no significant differences between groups on self-reported levels of parenting satisfaction (difference estimate 0·21, 95% CI -0·09 to 0·52), interest (-0·23, -0·62 to 0·16) and efficacy (-0·08, -0·38 to 0·22) on PSOC. INTERPRETATION: A pre-emptive intervention for the autism spectrum disorder prodrome had no immediate treatment effect on early autism spectrum disorder symptoms, the quality of parent-child interactions, or researcher-administered measures of developmental skills. However, we found a positive effect on parent-rated infant communication skills. Ongoing follow-up of this infant cohort will assess longer-term developmental effects. FUNDING: Western Australia Children's Research Fund, Autism Cooperative Research Centre, La Trobe University, and Angela Wright Bennett Foundation.