Decomposition of socioeconomic inequalities in preterm deliveries in Tehran, Iran

Abstract

Objective: To investigate associations between economic inequality in preterm delivery.

Methods: The present secondary analysis included cross-sectional data collected in interviews with patients following delivery at 103 hospitals in Tehran, Iran, between July 6 and 21, 2015. Principal component analysis was used to measure the socioeconomic status of participants and the concentration index was used to measure inequalities in preterm delivery among patients of different socioeconomic status.

Results: Data were included from 5170 patients. The concentration index for preterm delivery was 0.087 (95% confidence interval 0.036-0.134), indicating that preterm deliveries were concentrated among patients with higher socioeconomic status. Higher socioeconomic status (94%), younger maternal age (29%), younger paternal age (21%), and being a homemaker (17%) had the highest positive contributions to the measured inequalities in preterm deliveries; vaginal delivery (-58%) had the highest negative contribution.

Conclusion: Preterm deliveries were distributed unequally among the study patients in Iran, and were concentrated among patients of higher socioeconomic status. Alongside future etiological studies, reproductive programs in Iran should focus on this population to redress the observed inequality.

Keywords: Concentration index; Decomposition; Iran; Premature Birth; Socioeconomic inequality.