Table 3 Crude and adjusted hazard ratios for time to attrition

Certification level

Level 1–3

1.00

1.00

Level four

0.2 [0.17–0.3]*

0.4 [0.3–0.5]*

Diploma and degree

2.1 [1.7–2.6]*

3.3 [2.3–4.9]*

Annual leave

No annual leave

1.00

1.00

1–3 annual leaves

0.6 [0.4–0.7]*

0.84 [0.6–1.1]*

 ≥ 4 annual leaves

0.5 [0.4–0.7]*

0.9 [0.7–1.1]

Having biological children

No

1.00

1.00

Yes

0.4 [0.3–0.5]*

0.5 [0.4–0.7]*

Certificate of competence status

Certified

1.00

1.00

Not certified

1.9 [1.6–2.4]*

1.6 [1.3–2.0]*

Deployment year

2004–2008

1.00

1.00

2009–2013

2.0 [1.6–2.5]*

1.5 [1.1–1.9]*

2014–2019

3.5 [2.4–4.9]*

2.6 [1.7–3.8]*

Family size

1–3

1.00

1.00

 ≥ 4

0.5 [0.45–0.65]*

1 [0.75–1.2]

Woreda type

Rural

1.00

1.00

Urban

1.3 [1.1–1.8]*

0.5 [0.3–0.7]*