Table 1.

Definitions of variables used to explore factors associated with women’s use of MWHs in three districts in Jimma Zone, Ethiopia (2016–2017)

Variable	Definition
Outcome variable
Maternity waiting home use	Binary variable indicating stay at an MWH reported by women for any previous pregnancy (yes or no).
Independent variables
Education	Women’s responses on highest level of education completed (none, primary, secondary, tertiary) were collapsed into a binary variable (no formal schooling or some formal schooling).
Occupation	Women’s responses on their primary occupation were collapsed into a binary variable to reflect the main occupations listed (housewife or farmer/trader/other). Other occupations included government employee, student, domestic worker, private organisation employee.
Household wealth	An asset-based wealth index created using information on asset ownership (radio, television, mobile phone, motorbike, car/truck), number of animals owned (cows, sheep, poultry), electricity supply to home, health insurance, drinking water source, type of toilet and type materials used for construction of floors in the home.
Healthcare decision-making	Women were asked who usually makes decisions about (i) their own health and (ii) their children’s health. Women indicated whether they made decisions on their own, jointly with someone else or were not involved. Responses for both questions were collapsed into three categories: never involved, sometimes involved or always involved. ‘Never involved’ included women who described someone other than themselves being involved in healthcare decision-making for both themselves and their children. ‘Sometimes involved’ included women who described that they were either involved in healthcare decisions about their own health or decisions about their children’s health. ‘Always involved’ included women who described being involved in both healthcare decisions about their own health and that of their children.
Companion support for facility visits*	As part of an assessment of social support available to women during pregnancy, women were asked if they had someone to accompany them to health facility visits (yes or no). This dimension of support has been termed companion support.
Travel time to obstetric care facility	Women’s estimates of the time required to reach the nearest health facility able to provide obstetrical care were classified into two categories: (i) none nearby (ie >30 min) and (ii) ≤30 min away. Women who listed a health post as their nearest health facility were classified under‘none’ as health posts do not routinely provide delivery services. For the 5% of women who were unable to estimate travel, available husband responses were used to minimise missing data.
Community birthing norms	Percentage of women in a PHCU cluster that reported having ever given birth at a health facility.
Covariates and design variables
District	District of residence (Gomma, Seka Chekorsa or Kersa) reported by women.
Primary healthcare unit	Health system administrative level comprising a health centre and satellite health posts that functioned as cluster-level sampling unit in the trial.

*Several dimensions of social support including financial or in-kind assistance, emotional support and practical support were assessed in the survey. Companion support was the dimension most relevant for maternity waiting home use.

MWH, maternity waiting home; PHCU, primary healthcare unit.