Income is not an equalizer: health development inequities by ethnoracial backgrounds in California kindergartners.

BACKGROUND

Early childhood health development is positively associated with income, but the strength of this relationship with ethnoracial background remains unclear. This study examined the extent of health development inequities among California kindergarteners based on ethnoracial backgrounds and neighborhood-level income.

METHODS

This cross-sectional study assessed health development inequities by analyzing neighborhood-level income, ethnoracial background, and health development data for California kindergarteners. Student-level data (n = 106,574) were collected through teacher report between 2010-2020 across 52 school districts and 964 schools. Student addresses were geocoded and linked to American Community Survey neighborhood income levels. Health development was measured using the Early Development Instrument, a population-level measure which includes physical health and well-being, social competence, emotional maturity, language and cognitive development, and communication skills and general knowledge domains. Outcomes included being "on-track" in each domain as well as overall health development.

RESULTS

Using a Generalized Estimation Equation with a log-link function, while accounting for interactions between ethnoracial background, income, and income-squared, we found significant health development inequities by ethnoracial background and neighborhood-level income. Regarding overall health development, as well as the physical, social and emotional domains, Black students had a lower likelihood of being on-track compared to the weighted average across income levels, whereas Asian students surpassed the weighted average. White students exhibited the steepest slope, and at the lowest income levels, their health development scores were akin to their Black and Hispanic/Latino/a low-income counterparts but resembled their Asian counterparts at higher income levels. For the general knowledge and communication domain, white students consistently had the highest likelihood of being on-track, while Hispanic/Latino/a students had the lowest likelihood across all income levels.

CONCLUSION

This study examines health development inequities among California kindergarteners in diverse communities. Our analysis shows that the relationship between neighborhood-level income and kindergartners' health development varies by domain and is weaker for students of color. Given the scarcity of population-level data on health development outcomes, these analyses offer valuable insights for identifying ecosystems necessitating support in promoting equitable early childhood health development.