Evaluation of a Novel Intervention for Infants At Risk for Neurodevelopmental Disorders

Rationale:

Providing intervention during infancy, before the full emergence of the symptoms that would lead to a diagnosis of ND based on a behavioral phenotype (e.g., autism spectrum disorder (ASD), language disorder, or attention-deficit/hyperactivity disorder) is supported by 4 premises: (1) The first two years of life are an especially active period of neural development. Due to rapid synaptic proliferation and experientially-influenced shaping of functional connectivity, interventions initiated in infancy may be powerful in promoting more typical neural connectivity (2) Biologically-based differences in infants at-risk for NDs lead to observable differences in sensory reactivity and communication behaviors in most infants by 9-15 months, prior to the full emergence of diagnostic symptoms. (3) Differences in infant behaviors influence the quantity and quality of parent responses. (4) Parent-child transactional processes begin early in infancy and impact long-term child outcomes. Based on these premises, the investigators propose a "proof of concept" evaluation of a novel intervention, Parents and Infants Engaged (PIE), for prodromal infants at-risk for NDs. PIE is designed to directly impact parent responses to behaviors commonly observed in infants at-risk for NDs. Without intervention, these behaviors may fail to elicit parent responses that efficiently scaffold child communication development. Extensive research shows positive associations between caregiver responsiveness and child communication outcomes. Responsiveness is defined by multiple dimensions (i.e., sensitivity, contingency, encouragement, matching interests/activity level, physical affection, quality of language input [e.g., verbal scaffolding], reciprocity, and shared control), which vary within and across caregivers. Children play an active role in eliciting responses from caregivers, emphasizing the co-regulatory or transactional nature of these interactions. This includes biobehavioral co-regulation of arousal levels. Whereas much research comes from studies of typical development, similar transactions occur with young children with NDs. Parent responses vary depending on the preceding behaviors of the child. For example, parents are more likely to respond, and to give a verbal response, to their one-year-olds' gestures than nongestural communicative bids (vocalizations, gaze, actions); also, adults are more likely to respond to infants' speech-like than nonspeech-like vocalizations. Parent responsiveness, in turn, predicts communication outcomes of children with varied NDs.

Aims:

Specific Aim 1: Evaluate the differential changes in attuned parent responsiveness following coaching on two PIE domains - responses to variable infant (a) sensory reactivity (SR) or (b) prelinguistic communication (PC) - as well as cumulative changes in attuned parent responses following coaching on both PIE domains.

Specific Aim 2: Estimate the separate and combined effects of PIE intervention domains on parent-infant engagement and infant-initiated communication with parents.

Specific Aim 3: Determine the extent to which autonomic indices of infant self-regulation change over the course of the PIE intervention.

Recruitment:

To identify infants at-risk for neurodevelopmental disorders, the investigators will use a population-screening method based on birth records in North Carolina, supplemented with distribution of postcards/flyers through physician's offices and public health clinics and email and listserv announcements. Completed First Year Inventories (FYIs) will be scored and screened for risk status. Infants who score at-risk will be flagged, and those families will receive a phone call informing them of the results of the screening (by a qualified/trained project coordinator), and they will be invited for a more comprehensive developmental assessment.

Summary of Measures to be Completed at Each Assessment Time point:

Baseline/Pretest

• Full Mullen Scales of Early Learning (MSEL)
• Sensory Processing Assessment (SPA)
• Brief Observation of Social Communication Change (BOSCC)
• (Respiratory Sinus Arrhythmia (RSA)/ Skin Conductance Level (SCL) Protocol
• Parent-Child Interaction
• Attention Following Protocol
• Sensory Experiences Questionnaire (SEQ)
• MacArthur Bates Communication Development Inventory (MB-CDI)
• Parent Stress Scale

Posttest 1 (6-8 weeks after pretest):

• Parent- Child Interaction
• SEQ

Posttest 2 (13-16 weeks after pretest):

• MSEL Receptive and Expressive Language
• SPA
• BOSCC
• RSA/SCL Protocol
• Parent-Child Interaction
• Attention Following Protocol
• SEQ
• Intervention Rating Profile (intervention group only)

The intervention phases of the study will use a randomized comparative trial design, with two phases. For Intervention Study Phase 1, dyads will participate in the Pretest assessment battery; then the project methodologist will randomize families of eligible infants, stratifying randomization by age (<13 months, 30 days or ≥ 14 months). Families will be randomized to one of two treatment arms: Arm 1 families will participate in initial coaching on the SR domain of PIE, and Arm 2 families will participate in initial coaching on the PC domain of PIE. Families will participate in 6 coaching sessions in their respective treatment arms, and then return for Posttest-1 (to test the separate impacts of the PIE content domains on parent responses and infant outcomes). For Intervention Study Phase 2, dyads in Arm 1, will receive 6 coaching sessions on the PC domain, and dyads in Arm 2 will receive 6 coaching sessions on the SR domain; coaching for each group will also review their respective content domain coached in Intervention Study Phase 1. Then families will return for Posttest-2 (to evaluate the effects of the full PIE intervention).

Due to COVID-19 restrictions, intervention may be carried out via video-conference platform for no more than one session. Parent-report questionnaires only will be collected in lieu of in-person assessments for Posttest-2 for participants unable to attend in-person.

Data Analyses:

All data will be cleaned and inspected for outliers, missing data and distributional irregularities. Where error distributions potentially deviate from normality, or heteroscedasticity is suspected, the tests of the contrasts will be conducted using exact (resampling-based) nonparametric methods. Proportional outcomes will be arc sin transformed before entering them into the models. For the frequency count outcome, if counts are not sufficiently large (e.g., ≥ 8) that a normal approximation to a Poisson error distribution is appropriate, Poisson or negative binomial regression methods or nonparametric approaches may be employed.

All primary analyses will be conducted to explore a priori contrasts of interest within a repeated measures framework. Of primary interest will be the contrast of Pretest to Posttest-1 scores and the contrast of Pretest to Posttest-2 scores (time effect). In addition, the models will include terms for treatment arm effects and treatment arm-by-time interactions.

At Posttest-1, the investigators anticipate statistically significant time, treatment arm, and arm-by-time interactions, with parents showing differentially greater attuned responses to infant SR or PC, consistent with their respective treatment arm. By Posttest-2, however, the investigators predict group equivalence in responsiveness, with no differential time effects. A follow-up test of the contrast between Posttest-1 and Posttest-2 will verify that parents in Arm 1 maintained their attuned SR responsiveness gains, while parents in Arm 2 "caught up" on attuned SR responsiveness, and vice versa for PC attunement. For H2a, the investigators expect increases in joint engagement from Pretest to Posttest-1, with additional increases at Posttest-2 (time effects), and no differential treatment arm effects or interactions at either Posttest. For H2b, the investigators anticipate minimal increases in infant intentional communication at Posttest-1 in either treatment arm, with comparable improvements (time effects) in each group at Posttest-2. Similarly, on the physiological measures addressing H3a (measured only at Pretest and Posttest-2) the investigators anticipate comparable improvements in RSA and SCL (time effect) in both arms.

Although the investigators are performing multiple statistical tests across outcomes and hypotheses in addressing the specific aims, in this project it is more important to avoid overlooking statistical signals of effectiveness of the innovative PIE intervention approach (Type II errors), than avoiding false assertions of effectiveness (Type I errors). The investigators believe it is premature, therefore, to employ conservative adjustments to the Type I error rates in statistical tests, which would compromise the power of statistical tests to detect such signals. Assuming recruitment of 44 infant-parent dyads and allowing for a 9% (n=4) dropout rate, which is consistent with high retention rates (> 95%) in our prior intervention studies, 40 dyads (20 per treatment arm) will have complete data for analyses. Assuming a conventional Type I error rate of .05, and intercorrelations among the repeated measures from .3 to .7, the magnitude of treatment group effects detectable with a .80 statistical power will range from f=.37 to .42, respectively, which are large standardized effects. The magnitude of time effects and time-by-treatment arm interaction effects detectable with a .80 power will range from .27 to .18, also respectively, which are medium-sized standardized effects. Thus, the study is underpowered to detect any but large differences between the treatment arms and medium-sized or larger effects on time and time-by treatment arm interactions. More importantly than the statistical comparisons, though, the analyses will yield key descriptive characterizations of the treatment-arm effects at the two posttest points (i.e.,means, medians, proportions, and variances) on key outcomes, as well as effect size estimates that can be used in planning a larger scaled efficacy trial of the PIE intervention.