Why caesarean is more unequally concentrated among better-off people in Tehran? A concentration index decomposition approach

Background Iran, as one of the low-income and middle-income countries, has experienced a remarkable increase in the caesarean section (CS) rate during the past three decades. Although several studies have been conducted on the prevalence and risk factors affecting CS, but few studies were done regarding socioeconomic factors influencing the CS rate. The aim of this study was to identify socioeconomic inequalities and its determinants in CS in Tehran, capital of Iran. Methods A population-based cross-sectional study was conducted on 5170 pregnancies in Tehran, since 2015. Principal component analysis was applied to measure the asset-based economic status. Concentration index was used to measure socioeconomic inequality in CS and then decomposed in to its determinants. Results The concentration index and its 95% CI for CS history was 0.102 (0.091 to 0.112). Decomposition of the concentration index showed that economic status had the largest contribution (49.2%) to socioeconomic inequality in CS. Mother's education (14.9%), father's occupation (13.3%) and father's nationality (9.7%) had the next high positive contribution to measured inequality in CS, respectively. Conclusions CS is mostly concentrated among women with high economic status. The identified contributing factors should be addressed to decrease the socioeconomic inequalities as possible.