Cause-Specific Infant Mortality and Area-Level Deprivation in Russia: Associations and Policy Implications

Abstract

To examine the impact of regional socioeconomic and environmental deprivation on cause-specific infant mortality in Russia. Using data from the Russian Fertility and Mortality Database (2015–2022) covering 83 regions, we analyzed cause-specific infant mortality via multivariable negative binomial regressions, with the infant population applied as an offset term. In the primary analysis, models were adjusted for infant sex and place of residence (urban vs. rural) to capture group-specific risks. To evaluate the systemic robustness of deprivation effects against latent geographic processes and healthcare supply, a separate sensitivity analysis was performed on the total population without sex and residence stratification, integrating spatial eigenvector filtering and pediatrician density. In the baseline models adjusted for infant sex and place of residence, mortality rates from poisonings, injuries, and external causes escalated progressively alongside gradient increases in economic deprivation. These findings remained robust and unchanged upon the further integration of spatial eigenvectors and pediatrician density into the regression frameworks. Additionally, the primary stratified analysis revealed significantly elevated infant mortality from neoplasms specifically within environmentally deprived rural pockets. However, in the unstratified sensitivity framework, this highly localized rural hazard signal disappeared due to a classic signal dilution effect caused by aggregating data across the total regional population without urban-rural segmentation. This study provides the first empirical evidence that socioeconomic and environmental deprivation significantly shapes cause-specific infant mortality in Russia, demonstrating robust associations that vary by infant sex and residence, while highlighting the major mediating role of regional healthcare infrastructure.