Understanding determinants of unequal distribution of stillbirth in Tehran, Iran: A concentration index decomposition approach

Abstract

Objective The present inquiry set to determine the economic inequality in history of stillbirth and understanding determinants of unequal distribution of stillbirth in Tehran, Iran. Methods A population-based cross-sectional study was conducted on 5170 pregnancies in Tehran, Iran, since 2015. Principal component analysis (PCA) was applied to measure the asset-based economic status. Concentration index was used to measure socioeconomic inequality in stillbirth and then decomposed into its determinants. Results The concentration index and its 95% CI for stillbirth was-0.121 (-0.235 to-0.002). Decomposition of the concentration index showed that mother's education (50%), mother's occupation (30%), economic status (26%) and father's age (12%) had the highest positive contributions to measured inequality in stillbirth history in Tehran. Mother's age (17%) had the highest negative contribution to inequality. Conclusions Stillbirth is unequally distributed among Iranian women and is mostly concentrated among low economic status people. Mother-related factors had the highest positive and negative contributions to inequality, highlighting specific interventions for mothers to redress inequality.