Classifying infants and toddlers with developmental vulnerability: who is most likely to receive early intervention?

Background Infants and toddlers with developmental difficulties represent a heterogeneous group who often receives early intervention ( EI ). Notable population heterogeneity exists and complicates unmet need and effectiveness research. However, a mix of relatively homogeneous clinically policy relevant ‘subgroups’ may create the apparent heterogeneity. To date, methodological challenges have impeded identifying these potential groups and their policy‐relevance. Methods From the 2005–2006 N ational S urvey of C hildren with S pecial H ealth C are N eeds, we derived a sample ( n  = 965) of infants and toddlers with parent‐reported developmental difficulties. We used latent class analysis ( LCA ) to identify subgroups of developmental vulnerability based upon functional, social and biological characteristics that would make children eligible for EI . Mixture modelling estimated the likelihood of each subgroup receiving parent‐reported EI , controlling for race/ethnicity, child's age, and state of residence. Results LCA identified four distinct subgroups of developmental vulnerability: developmental disability (Group 1), mild developmental delay (Group 2), socially at risk with behaviour problems (Group 3), and socially at risk with functional vision difficulties (Group 4). Black, non‐ H ispanic children are significantly more likely than their white counterparts to be in Group 3 ( β  = 1.52, P  = 0.001) or group 4 ( β  = 1.83, P  < 0.001). Compared with children with a mild developmental delay (Group 2), children in group 1 ( β  = −0.61, P  < 0.001), group 3 ( β  = −0.47, P  = 0.001) and group 4 ( β  = −0.38, P  = 0.009) are significantly less likely to receive EI . Conclusions Racial and ethnic differences exist with regard to membership in developmental vulnerability subgroups. Observed inconsistencies in access to EI suggest the need for improved surveillance, referral and outreach.