**2.2 Explanatory variables**

The C-section delivery is an outcome of demographic, socioeconomic, insurance status and institutional factors. Among demographic factors, maternal age at last birth (below 20, 20–24, 25–29 and 30+ years) and birth order (first birth order, second birth order and third birth order or above) were taken. The level of mother's education (no schooling, up to 5 years, 6–10 years, 11+ years), household wealth index (poor, middle and rich), religion (Hindus, Muslims and others), caste/tribe (Scheduled Caste (SC), Scheduled Tribe (ST) and others or general) and place of residences (rural and urban residence) were taken from socioeconomic factors. Coverage by health insurance scheme (yes, no) was also included as an explanatory variable. Antenatal care services include the number of ANC visits (up to three times, four to seven times and eight or more times) and places of ANC services (no ANC visits, only public health facilities, only private health facilities, public/private health facilities, and home or elsewhere), and the place of delivery (public health facilities, private health facilities) were taken from institutional factors.

## **2.3 Statistical analysis**

The differences in C-section delivery by women's background characteristics were gross differentials and had been obtained through bivariate analysis. As a number of factors were strongly associated with each other, there was the possibility of confounding. Therefore, it was necessarily desirable to detect the net effect. For this purpose, logistic regression model had been used. In this model, the coefficient (B) and odds ratio (Exp B) were estimated. In order to assess the true differences, it was desirable to obtain adjusted probabilities; by that one can see the actual difference in probabilities [35]. The adjusted probabilities were computed from the coefficients of logistic regression analysis for C-section delivery. A p-value of less than and equal to 0.05 was considered as the significant association between independent variable and outcome variable.
