A developmental surveillance score for quantitative monitoring of early childhood milestone attainment (Preprint)

BACKGROUND Developmental surveillance, conducted routinely worldwide, is fundamental for timely identification of developmental delays. It is typically executed by assessing attainment of age-appropriate milestones. Unlike developmental screening and evaluation methods, surveillance tools lack standardized quantitative measures, and consequently the interpretation of their results is inevitably subjective. OBJECTIVE In this work we suggest a novel method for aggregating developmental surveillance assessments into a single score that coherently depicts and monitors child development. We aim to demonstrate the utility of this score by exemplifying how it captures population-level associations and describes child level longitudinal patterns. METHODS We present Developmental Surveillance Score (DSS), a simple-to-use tool that integrates the age-dependent severity of failure at attaining developmental milestones. We use the Israeli developmental surveillance scale to assign the severity levels and evaluate the score using a nationwide cohort of over one million children assessed at Israeli Maternal Child Health Clinics. We measure the score’s ability to capture known associations between developmental delays and characteristics of the mother and child. In addition, we use cluster analysis to identify distinct patterns of the score’s longitudinal trajectories per child. RESULTS Evaluating the score on subpopulations of the cohort, stratified by risk factors of developmental delays, reveals expected relations between developmental delay and characteristics of a child and mother, such as gestational age and demographics. On average the score is worse for preterm children compared to on-term and for males compared to females, and it is correspondingly lower for lower levels of maternal education. Clustering the trajectories of scores per child between birth and 36 months revealed three main types of developmental patterns, which are consistent with the clinical experience – children who successfully attain milestones, children who initially tend to fail but improve over time, and children whose failures tend to increase over time. CONCLUSIONS The suggested score is simple to compute, and highlights known and novel relations between developmental delay and characteristics of a child and mother. Additionally, it allows monitoring the developmental trajectory of a child and characterizing it. Future work is needed to calibrate the score, validate it worldwide, and to integrate it into the clinical workflow of developmental surveillance.