Standardization of a Developmental Milestone Scale Using Data From Children in Israel

Abstract

Importance: Routine developmental screening tests for children are used worldwide for early detection of developmental delays. However, assessment of developmental milestone norms lacks strong normative data, and there are inconsistencies among different screening tools.

Objective: To establish milestone norms and build an updated developmental scale.

Design, setting, and participants: This is a cross-sectional, population-based study conducted between 2014 and 2020. Developmental assessments were conducted by trained public health nurses, documented in national maternal child health clinics, known as Tipat Halav, which serve all children in Israel. Participants included all children born between January 2014 and September 2020, who were followed at the maternal child health clinics from birth to age 6 years. Exclusion criteria were preterm birth, missing gestational age, low birth weight (<2.5 kg), abnormal weight measurement (<3% according to standardized child growth charts), abnormal head circumference measurement (<3% or >97% according to standardized child growth charts), and visits without developmental data or without the child's age. Data analysis was performed from September 2020 to June 2021.

Exposures: In total, 59 milestones in 4 developmental domains were evaluated, and the achievement rate per child's age was calculated for each milestone.

Main outcomes and measures: A contemporary developmental scale, the Tipat Halav Israel Screening (THIS) Developmental Scale, was built, presenting the 75%, 90%, and 95% achievement rates for each milestone. The THIS scale was compared with other commonly used screening tests, including the Denver Developmental Screening Test II (Denver II), the Alberta Infant Motor Scale (AIMS), and the Centers for Disease Control and Prevention (CDC) Developmental Assessment.

Results: A total of 839 574 children were followed in the maternal child health clinics between January 2014 and September 2020 in Israel, and 195 616 children were excluded. A total of 3 774 517 developmental assessments were performed for the remaining 643 958 children aged 0 to 6 years (319 562 female children [49.6%]), resulting in the establishment of new developmental norms. In terms of the comparable milestones, THIS milestones had a match of 18 of 27 (67%) with the Denver II, 7 of 7 (100%) with AIMS, and 10 of 19 (53%) with the CDC Developmental Assessment. The remaining unmatched milestones were achieved earlier in the THIS scale compared with other screening tools.

Conclusions and relevance: The THIS developmental scale is based on the largest population evaluated to date for developmental performance, representing the heterogeneous, multicultural population comprising this cohort. It is recommended for further evaluation worldwide.

Figure 1.. Participant Enrollment Flowchart

Overview of the study population, including the exclusion criteria and total developmental assessments at each age group.

Figure 2.. Tipat Halav Israel Screening Developmental Scale

The rows represent the evaluated milestones, the columns represent the age by month (top panel) and year (bottom panel). Each milestone is colored according to the relevant field, as shown in the key (fine motor, gross motor, personal-social, and language). For each milestone the success rate is shown, each indicating a success threshold of less than 75% to 90%, 90% to 95%, and greater than 95%. For example, the milestone “vocalizes in response to human voice” is achieved by less than 75% of children at the age of 0 months, 75% to 90% of children at the age of 1 month, and more than 95% of children at the age of 2 months.

Figure 3.. Comparison of Developmental Milestones Between Different Screening Tools

Graphs show comparisons of the milestones at each field (personal-social, language, fine, and gross motor), between the Tipat Halav Israel Screening (THIS) developmental scale and the different commonly used screening tools (Centers for Disease Control and Prevention [CDC] Developmental Assessment, Alberta Infant Motor Scale [AIMS], and Denver Developmental Screening Test II [Denver]). The orange symbols represent milestones with clinically meaningful differences in achievement age between the different screening tools.