Table 1 Description and measurement of variables included in the mixed effect multilevel model, rural Tigray region, Ethiopia 2017

 Postpartum contraceptive use

This is defined as a women’s use of any modern method of contraception during the 12 months following their most recent childbirth. The outcome variable categorized as yes response is coded’1′ and no as ‘0′.

 Individual-level variables

Level 1- determinant variables

 Marital status

Marital status of respondent [currently married and un married].

 Maternal age

Self reported age of respondent at the time of the survey [15–49 years].

 Maternal and husband educational-level

Highest level of education level [None/Primary; Secondary or higher].

 Birth order

Birth order of women’s most recent birth [index birth]. It is divided in to three categories: first and second birth, 3rd– 4th and ≥ 5th.

 Birth interval

Birth interval is the length of time between two successive live births. It is divided in to three: <  24 months, 24–36 months and > 36 months.

 Parity

Number of children ever given birth [None; One or more].

 Wealth index

This is computed by principal component analyses from ten variables (based on the ownership of a farmland, own toilet facility, bank account, mobile phone, electricity, corrugated iron sheet roof, number of cows/oxen, horses/mules/donkeys, goats/sheep and chicken). The wealth index is categorized in to five groups and ranked from poorest (first) to wealthiest (fifth) quintile.

 ANC use

Proportion of women who have received ANC at least one and above visit either at health center, hospital or health post.

 Place of delivery

Proportion of women who have given birth at either at health center, hospital or health post.

 PNC use

Proportion of women who have postnatal care at least one visit either at health center, hospital or health post.

 Received FP counseling during prenatal

Any study participants who received family planning (FP) counseling during prenatal, yes ‘responses are coded as ‘1′ and no response as ‘0′.

 History of complication during delivery

An individual study participants who have severe pre-eclampsia, eclampsia, bleeding during intra partum, abnormal presentation of the fetus, prolonged labour, obstructed labour, breech delivery, and cervical tear, if the study participants experienced at least any one of the above, it is categorized as 1(yes), if not 0 (no).

 Model household

A household that applied all health extension packages at their home and got certificates of appreciations from health extension workers. Yes ‘responses are coded as ‘1′ and no response as ‘0′.

 Community-level variables

Level 2-determinant variables

 District -level of ANC use

Proportion of women in the district received 4⁺ANC and above visit. It is categorized in to two: high and low-level.

 Source of income

The cluster’s population main source of income. It is categorized in to two: farming and mixed (farming & trading).

 Distance

Distance in kilometer of villages in each cluster to the nearest health facility. It is categorized in-to three: < 1 km, 1–5 km and > 5 km.

 District residence

Current district residence [Rural Adwa, Tanquae-Abrgelle, Laelay -Maychew and Tahtay- Maychew].