Materials and Methods

Data Source

The data for this study comes from the seventh round of the IDHS conducted in 2012 by Statistics Indonesia (Badan Pusat Statistik– BPS) in collaboration with the National Population and Family Planning Board (BKKBN) and the Indonesia Ministry of Health (MoH). The 2012 IDHS covered a nationally representative sample from households sampled using a multistage stratified cluster sampling design (Statistics Indonesia, BKKBN, MOH, & ICF International, 2013). Although previous studies have demonstrated the limitations of CS delivery data from DHS (Holtz & Stanton, 2007; Stanton, Dubourg, De Brouwere, Pujades, & Ronsmans, 2005), this is one of the most reliable sources of information of nationally representative CS rate in Indonesia.

Ethics Statement

This study is a further analysis of a publicly available de-identified secondary data. We download the dataset from the DHS program website <www.dhsprogram.com/Data> after obtaining permission. Hence, we deem that a further ethical review is unnecessary.

Study Population and Sample Size

We used a sample of 18,021 births that occurred during the five years preceding the survey. Following Khawaja et al. (2004), we restrict the analysis to the most recent births during the five years preceding the survey to reduce recall bias. The initial sample size is 15,262 births (Statistics Indonesia et al., 2013). Births with missing information on the dependent and independent variables were excluded from the analysis (n = 383). As such, the final analytic sample included 14,879 most recent births (97.49% of the initial sample).

Variables

The outcome variable, CS delivery, is measured by a binary variable that takes the value of one if the delivery method for the latest pregnancy was a caesarean section, and zero otherwise. The independent variables in this study consist of socio-demographic and spatial characteristics. As socio-demographic characteristics, maternal age, parity, any complications during pregnancy, number of prenatal care (PNC) visits, delivery took place in a private health facility, mother’s and father’s years of formal schooling (in years), ownership of health insurance, and quintiles of wealth index have been included in the analysis. We use the provided wealth index that was created through three steps (Statistics Indonesia et al., 2013). Moreover, we also use two spatial characteristics, namely region (Java, Sumatera, Bali and Nusa Tenggara, Kalimantan, Sulawesi, and Maluku and Papua) and place of residence (urban/rural).

Statistical Analysis

We estimate bivariate and multivariate logit regressions, presenting average marginal effects (AMEs) and 95 % confidence intervals. All regressions were based on weighted data using sampling weights and sampling design of the 2012 IDHS. All hypotheses are tested using two-tailed p values <0.05. As for the descriptive analysis, we calculate and present descriptive statistics as percentages or means in Table 1. We conducted all of the analyses using Intercooled STATA version 13.1 (StataCorp LP, College Station, Texas).