Can combining existing behavioral tools improve identification of infants at elevated likelihood of autism in the first year of life?

Abstract

Identifying infants at elevated likelihood for autism and other developmental differences in the first year of life remains a significant challenge. This study explored associations between behavioral differences in infancy and developmental outcomes in toddlerhood. We conducted a secondary data analysis of 256 infants with an older autistic sibling followed from 6 to 36 months of age. We defined conceptually driven cutoffs for three behavioral measures collected at 6, 9, and 12 months and examined the utility of these measures, individually and in combination, in predicting 36-month outcome classification (typical development or developmental concerns, including autism). Overall, relatively few infants met multiple measure definitions (range: 5 to 43 infants across ages). However, infants meeting multiple definitions had a higher likelihood of developmental concerns outcomes at all ages. Positive predictive values for meeting all three measure definitions combined ranged from 0.67 [0.22, 0.96] at 6 months to 0.95 [0.75, 1.0] at 12 months. These findings suggest that while majority of infants ultimately classified with developmental concerns do not show significant behavioral differences in the first year, when early differences are present, they have predictive value. Combining behavioral tools may help to improve identification of infants most in need of early supports. Lay abstract Many families have concerns about their infants’ development in the first year of life. Current screeners cannot tell whether these differences might be related to autism, developmental delays, or likely to resolve on their own. As a result, many families are told to “wait and see.” In this study, we looked at whether combining multiple behavior measures can improve prediction of outcomes in toddlerhood. This could help to provide families with more information about the significance of early behavioral differences. We assessed 256 infants with an older autistic sibling at 6, 9, and 12 months. We created three markers of behavioral differences at these ages. We looked at whether infants who had two or more markers were more likely to be on the autism spectrum or have other developmental differences than to have typically developing outcomes at 36 months. We found that very few infants had more than one marker at any age. However, infants who showed two or more markers were more likely to be on the spectrum or have other developmental differences at 36 months than infants who showed only one marker. These findings suggest that when behavioral differences are present on multiple measures, there is no need to wait and see before referring for services.