Research Review: Outcomes of 24‐ to 36‐month‐old children with autism spectrum disorder vary by ascertainment strategy: a systematic review and meta‐analysis

Abstract

Background Despite widespread recommendations for early surveillance of risk for autism spectrum disorder (ASD), no research to date has shown that early surveillance leads to better clinical outcomes. Preliminary research has suggested that children with ASD ascertained via prospective follow‐up have better outcomes than those ascertained via community referral. Because prospective studies include early surveillance, by comparing outcomes of children with ASD across ascertainment strategies, we may gain insight into the effects of early surveillance relative to its absence. Methods A systematic review was conducted to identify studies reporting outcomes of 24‐ to 36‐month‐olds with ASD ascertained via prospective follow‐up, community referral, or universal screening. A meta‐analysis using a random effects model was used to calculate overall effect size estimates for developmental level and symptom severity across ascertainment cohorts. Results Eleven prospective, ten community referral, and eight universal screening studies were identified, reporting on 1,658 toddlers with ASD. We found no differences in outcomes between community referral and universal screening studies. Relative to both, prospective studies reported significantly higher developmental levels and lower symptom severities. Conclusions Outcomes of young children with ASD ascertained via prospective follow‐up are better than those of children with ASD recruited via community referral or universal screening. Although we discuss why sampling bias is not likely the driving force behind these findings, we cannot rule out the possibility that sampling bias contributes to the observed differences; future studies should probe the effects of sociodemographic variables on clinical outcomes as a function of ascertainment strategy. This limitation notwithstanding, our results raise the possibility that prospective follow‐up may confer a ‘surveillance effect’ that contributes to improved developmental and diagnostic outcomes in children with ASD. Future research should test this hypothesis and determine the specific mechanism by which surveillance may improve outcomes.

Affording autism an early brain development re-definition

“…In this view, science should strive to understand the interplay between genetic risks and disruptions of normative processes preceding the emergence of symptoms, and treatments should be developed to optimize outcomes, by either normalizing experience or by introducing compensatory learning (Zwaigenbaum et al, 2015). The corollaries of this view are straightforward: there is no need to wait for discoveries of what causes ASD or for “cures” to treat the condition because early treatment might promote best outcomes given a child's inborn risks; these best outcomes are unlikely to mean the erasure of a genetic trait or constellation of traits (like “autism,” or social ability/disability), but the prevention, or amelioration, of associated burdens such as intellectual, language communication or behavioral disabilities (Micheletti et al, 2020). In this light, the lack of investment in early detection and diagnosis is profoundly unethical since whether or not inborn risks convert into a lifetime of disability is dependent on what happens to the child's early life, and this, in turn, can be intervened with via early treatment.…”

“…And second, the belief of ASD as a deterministic, genetically based disease or disorder, has also resulted in a state of literature that almost virtually ignores the possibility that socio-demographic variables, and early childhood and family hardships associated with these variables, could play a role in determining the outcomes of children vulnerable to ASD (Bornstein et al, 2013; Micheletti et al, 2020). One rarely hears of debates on healthcare disparities, adverse childhood experiences, or social determinants of health in the cases of children with very rare genetic diseases, such as leukodystrophies and highly penetrant genetic syndromes of intellectual disabilities.…”

“…But in the case of vulnerable infants and toddlers, there is a need to train and support caregivers, to deliberately engineer social interactive engagement using behavioral principles (Schreibman et al, 2015), so that caregivers can leverage every moment of daily experiences to promote social–communicative development (Wetherby et al, 2014), thus alleviating the deleterious implications of thousands of missed opportunities for social learning experienced by infants and toddlers with ASD every day. In contrast to ethical concerns debated in the past (Yudell, Tabor, Dawson, Rossi, & Newschaffer, 2013), parents of babies at high risk for ASD are reassured and feel supported by, and thankful for, prospective monitoring and expert guidance. There is some evidence to suggest that this form of cost-effective and community-viable practice is in itself beneficial for children's outcomes (Micheletti et al, 2020), and parent-coaching practices may have benefits for a much broader range of vulnerable children including those growing up in low-income environments (Ferjan Ramírez et al, 2020) (see below), thus allaying fears of the cost of “false positives” in universal screening, which tend to be children with non-ASD developmental concerns that are actionable and likely to benefit from early intervention (e.g., Robins et al, 2014). Given the multiplicity of causes of ASD, the homogeneity of phenotypic expression (the fact that despite vast behavioral heterogeneity there is great validity in the nosologic category), comes from what the various causes disrupt (rather than commonalities across the causes), namely reciprocal social interaction between child and caregiver, which is the universal platform for early social and communicative brain development.…”

“…In contrast to ethical concerns debated in the past (Yudell, Tabor, Dawson, Rossi, & Newschaffer, 2013), parents of babies at high risk for ASD are reassured and feel supported by, and thankful for, prospective monitoring and expert guidance. There is some evidence to suggest that this form of cost-effective and community-viable practice is in itself beneficial for children's outcomes (Micheletti et al, 2020), and parent-coaching practices may have benefits for a much broader range of vulnerable children including those growing up in low-income environments (Ferjan Ramírez et al, 2020) (see below), thus allaying fears of the cost of “false positives” in universal screening, which tend to be children with non-ASD developmental concerns that are actionable and likely to benefit from early intervention (e.g., Robins et al, 2014).…”

Moving Toward Telehealth Surveillance Services for Toddlers at Risk for Autism During the COVID-19 Pandemic

“…For all these reasons, our priority has been to maintain regular contact and support the families whose child was being followed in his developmental trajectory by the multidisciplinary team, in order to continue the active surveillance of toddlers at risk for ASD during the COVID-19 crisis. Indeed, a recent review of longitudinal studies on FR toddlers reported that the prospective follow-up strategy improves their developmental outcome, creating a sort of "surveillance effect" through which parents, who have the possibility to talk regularly about their child's development with clinical experts, can learn new strategies to interact with their high-risk infants, reducing, in turn, their symptom severity (33).…”