Gesture screening in young infants: Highly sensitive to risk factors for communication delay.

Introduction: Children's early language and communication skills are efficiently measured using parent report, for example, communicative development inventories (CDIs). These have scalable potential to determine risk of later language delay, and associations between delay and risk factors such as prematurity and poverty. However, there may be measurement difficulties in parent reports, including anomalous directions of association between child age/socioeconomic status and reported language. Findings vary on whether parents may report older infants as having smaller vocabularies than younger infants, for example.

Methods: We analysed data from the UK Communicative Development Inventory (Words and Gestures); UK-CDI (W&G) to determine whether anomalous associations would be replicated in this population, and/or with gesture. In total 1204 families of children aged 8-18 months (598 girls, matched to UK population for income, parental education and ethnicity as far as possible) completed Vocabulary and Gesture scales of the UK-CDI (W&G).

Results: Overall scores on the Gesture scale showed more significant relationships with biological risk factors including prematurity than did Vocabulary scores. Gesture also showed more straightforward relationships with social risk factors including income. Relationships between vocabulary and social risk factors were less straightforward; some at-risk groups reported higher vocabulary scores than other groups.

Discussion: We conclude that vocabulary report may be less accurate than gesture for this age. Parents have greater knowledge of language than gesture milestones, hence may report expectations for vocabulary, not observed vocabulary. We also conclude that gesture should be included in early language scales partly because of its greater, more straightforward association with many risk factors for language delay.

What this paper adds: What is already known on the subject We already know that it is possible to measure children's early communicative skills using parent-completed inventories (Communicative Development Inventories, CDIs) and that some aspects of early communication can predict which children are likely to go on to have long-lasting communicative development difficulties. We also know that most uses of CDIs include only vocabulary, not early gesture. In addition, child-related and family-related variables such as prematurity, family history of language disorder and socioeconomic status may be related to communication development. What this paper adds to existing knowledge We looked at a large sample (N = approx. 1200) of families representative of the UK population with an infant aged 8 through 18 months and asked them about their infant's comprehension and production vocabulary as well as their early gesture skills. Gesture was more closely related to possible risk factors for communication development difficulties, for example, family history of communication difficulties, prematurity and multiple birth status. Vocabulary was only related in a straightforward way to family history and had complex relationships to socioeconomic differences. Families with different economic backgrounds may approach questions about their child's development in different ways. What are the potential or actual clinical implications of this work? We suggest that clinicians need to ensure that not only vocabulary but also gesture ability is assessed when looking at very early communication skills. We also suggest that gesture may be more predictive of later communicative development difficulties, and that clinicians need to be sure that parents are clear on how vocabulary questions are asked and what exactly is required of them in answering these types of questions.