Summary of the variables used in the study
| Variable name | [Coding, type]: definition |
|---|---|
| Antenatal care (ANC) visits | [Categorical, dependent variable]: ANC was assessed at three levels: (a) no antenatal care visit in the first trimester vs at least one antenatal care visit in the first trimester, (b) less than four antenatal care visits vs at least four visits and (c) inadequate antenatal care visits vs adequate antenatal care visits, where adequate was defined as attending at least four ANC visits, with the first visit made during the first trimester of the pregnancy. |
| Skilled birth attendance (SBA) | [Categorical, dependent variable]: women who lacked skilled attendance at birth vs those who received skilled attendance at birth (doctor, nurse and midwife). Auxiliary health staff and health assistants included in the 2008 and 2014 surveys were not considered as SBAs. |
| Maternal age | [Continuous variable, independent variable]: women 15–24 years with birth history |
| Urbanicity | [Two categories, independent variable] |
| Rural | Women who lived in rural areas based on national categorisations |
| Urban | Women who lived in urban areas based on national categorisations |
| Education level* | [Four categories, independent variable] |
| Never attended school | Women who confirmed having no formal education |
| Basic education | Women with some level of formal education not exceeding 9 years, including those with primary, middle school or lower secondary/high school education |
| Senior high school | Women who completed up to 12 years of formal education or those whose education ended at the upper secondary/high school level |
| Tertiary or higher education | Women who completed at least 15 years of formal education, including those with college, polytechnic or university level studies |
| Wealth | [Three categories, independent variable]: household wealth, which is consistent with expenditure and income among households, was calculated using household assets data collected from DHS surveys. These assets or consumer items consist of durable consumer goods, such as a television, bicycle and car, as well as dwelling characteristics, such as source of drinking water, sanitation facilities and type of flooring material. These were combined into a single wealth index† |
| Current marital status | [Two categories, independent variable] |
| Single | Women who had never married, were separated, divorced or widowed at the time of the interview |
| Married | Women who were married or living with a partner at the time of the interview |
| Parity | [Three categories, independent variable]: this variable was coded from the question that assessed the number of children ever borne by the woman. Nulliparous women (zero births prior to the survey) were not included in this study. |
| Para 1 | Only 1 birth |
| Para 2 | 2 births |
| Para 3+ | 3 or more births |
| Region of residence | [Ten categories, independent variable]: these represented the 10 administrative regions of Ghana: Western, Central, Greater Accra, Volta, Eastern, Ashanti, Brong-Ahafo, Northern, Upper East and Upper West regions |
| Religion | [Nine categories, independent variable]: these categories were based on the reported religious affiliations as follows: Catholic, Anglican, Methodist, Presbyterian, Pentecostal/charismatic, other Christians, Islamic, Traditional/Spiritualist, no religion and other |
* Educational level was reclassified as three categories: no education, basic education and senior high school or higher (secondary+).
†The index was constructed from household asset data using principal components analysis.32–34 They were then divided into five groups of equal size, or quintiles (poorest, poorer, middle, richer, richest), based on each household's relative standing on the wealth index. In this study, wealth was further ranked into three groups: poor (poorest and poorer), average (middle) and rich (richer and richest) using the fractional rank function in SPSS, in accordance with previous studies using DHS data from Ghana,30 ,31 where these subgroups have been shown to be comparable (more homogeneous in respect to the outcomes studied).