Language and beyond: a registered report examining single and multiple risk models of later reading comprehension weaknesses

Children with poor reading comprehension tend to have oral language weaknesses, suggesting that poor language in the early years is a proximal cause of later reading comprehension difficulties. Yet, longitudinal studies have not succeeded in reliably predicting which children go on to have comprehension weaknesses, and evidence comprises small sample sizes and a narrow focus on language in isolation. In this registered report, we examined early predictors of later outcomes in 879 children with comprehension weaknesses identified at 9 years in the Avon Longitudinal Study of Parents and Children. Study 1 showed that these children had poorer language at 24 and 38 months (but not 15 months) than peers who did not go on to develop reading difficulties (n=4516). However, preschool language ability was a poor predictor of individual outcomes, which was not improved by accounting for the language and communication environment. Study 2 used a multiple risk approach to ask whether breadth (number) or depth (severity) of risk factors predicted reading outcomes in a subsample of 125 children with comprehension weaknesses and 561 typically developing readers. Having three or more risk factors increased risk for later comprehension weaknesses. Language was the most consistent predictor of group membership, but the depth of cognitive risks beyond language were associated with the severity of reading impairment. However, neither the breadth nor depth of risks could adequately predict individual outcomes. These findings align with a multiple risk view of reading comprehension weaknesses and highlight the challenges in early identification.