Residential Socio-Demographic Scoring and Child Growth.

Background: While individual socioeconomic attributes have been widely studied in relation to child growth, the associations with broader, area-level socio-demographic characteristics of residential areas have not been thoroughly assessed.

Objectives: To examine the associations between area-level socio-demographic features of small residential areas and child growth trajectories.

Methods: We conducted a population-based retrospective cohort study, including all children born in Israel from 2004 to 2018, who underwent postnatal follow-up in the Mother and Child Health Clinics (MCHC) of the Ministry of Health. The MCHC network covers a significant proportion of the Israeli paediatric population, providing vaccination and developmental assessments to children up to 6 years old. Socio-demographic scoring was retrieved from the Israel Bureau of Statistics' geographical unit grading system, established for 990 rural areas and 1629 micro-geographical areas in 81 cities, using various population measurements. Height-for-age (HAZ) and weight-for-age (WAZ) z-scores were calculated using data from MCHC visits at birth and specific intervals.

Results: A total of 1,485,198 children were included (51.3% male). The mean birthweight and length were 3210 ± 52.2 g (z = -0.22) and 49.4 ± 3.33 cm (z = -0.06), respectively. Children resided in low (47%), intermediate (24.4%) and high (28.5%) socioeconomic areas. Throughout follow-up, children from low SES areas had consistently lower HAZ and WAZ scores across all birthweight groups, particularly among those with normal and high birthweight. In linear mixed-effects models, birth HAZ and WAZ scores were higher in high vs. low SES areas (β = 0.3 and β = 0.1, respectively), with non-linear growth trajectories characterised by early advantages in higher SES groups, a plateau in mid-childhood and renewed growth acceleration later in childhood.

Conclusions: The study provides evidence of impaired child growth in lower socio-demographic areas. This underscores the importance of identifying areas based on global attributes to identify regions predisposed to child growth impairment, particularly in developed nations.