Heterogeneous Trajectories of Delayed Communicative Development From 12 to 36 Months: Predictors and Consequences

The objective of the study was to identify distinct trajectories of delayed communicative development from 12 to 36 months and examine differences in risk factors and developmental outcomes for each trajectory.

Participants were 2192 children drawn from a prospective longitudinal pregnancy cohort in a large Canadian city. Maternal pregnancy medical records were used to determine perinatal risk factors. The Ages and Stages Questionnaire Communication subscale was administered at 12, 24, and 36 months. At 36 months, mothers reported on the child's health, cognitive, and behavioral development.

Using growth mixture modeling, we identified 4 trajectories of communicative development. Most children (81.1%) were characterized by high and stable scores from 12 to 36 months. The remaining children fell into a low-increasing class (13.0%), a moderate-stable class (4.5%), and a low-decreasing class (1.4%). At 36 months, the low-increasing class had caught up to the high-stable group. However, by 36 months, the low-decreasing class fell under the recommended "referral" cutoff, and the moderate-stable class fell under the "monitoring" cutoff criteria. Children with continued communication problems at 36 months were more likely to have a congenital anomaly and lower family income than late-talking children who had caught up.

Repeated assessments of a brief screening tool were able to differentiate patterns of communicative development over time, each with unique risk factors and developmental outcomes. Results highlight the potential for risk factors and repeated screenings to help identify children most at risk for persistent communication delays and in need of early support services.