Table 4.

Hazard ratios of having first birth among female adolescents by birth cohort (Cox model), Nairobi informal settlements, 2007

	Hazard ratios (95% CI)
	15- to 17-year-old			18- to 19-year-old
Variables	Model 1	Model 2	Model 3	Model 4	Model 5	Model 6
Socio-demographic variables
Age (years)	1.22 (0.56–2.67)	1.20 (0.45–3.20)	1.12 (0.21–6.08)	0.85 (0.55–1.31)	0.73 (0.46–1.14)	0.81 (0.51–1.29)
Slum residence (ref. Koch)
Viwandani	0.81 (0.27–2.44)	0.24** (0.06–0.94)	0.31 (0.04–2.41)	0.89 (0.53–1.49)	0.92 (0.57–1.48)	1.06 (0.67–1.70)
Education (ref. primary)
Never attended	4.95 (0.60–41.04)	2.00 (0.42–9.42)	4.80 (0.60–38.67)	2.06 (0.49–8.67)	1.88 (0.61–5.79)	2.74 (0.77–9.80)
Secondary or higher	0.13* (0.02–1.05)	0.29 (0.04–2.35)	0.20 (0.01–3.61)	0.41*** (0.24–0.70)	0.57** (0.35–0.94)	0.67 (0.37–1.18)
Other	0.30 (0.04–2.05)	0.05*** (0.01–0.33)	0.21 (0.01–4.61)	0.73 (0.10–5.17)	0.33 (0.03–4.45)	0.42 (0.03–5.12)
Currently in school	0.00*** (0.00–0.00)	0.00*** (0.00–0.00)	0.00*** (0.00–0.00)	0.00*** (0.00–0.00)	0.00*** (0.00–0.00)	0.00*** (0.00–0.00)
Born in slums	0.64 (0.27–1.53)	0.71 (0.25–1.97)	0.47 (0.14–1.66)	0.68 (0.40–1.13)	0.98 (0.58–1.67)	0.95 (0.57–1.59)
Mother alive	0.56 (0.07–4.38)	0.67 (0.13–3.40)	0.43 (0.06–2.88)	0.67 (0.34–1.34)	0.79 (0.39–1.58)	0.60 (0.29–1.23)
Father alive	1.77 (0.43–7.23)	1.87 (0.48–7.27)	2.80 (0.39–20.16)	0.87 (0.55–1.38)	0.98 (0.59–1.62)	0.96 (0.58–1.59)
Ever used contraception			0.98 (0.13–7.64)			0.73 (0.39–1.37)
Transition markers
Married		18.46*** (6.67–51.12)	13.72*** (1.99–94.40)		8.16*** (5.15–12.95)	8.22*** (5.24–12.90)
Owned or rented a house		1.44 (0.40–5.19)	1.12 (0.15–8.28)		1.14 (0.71–1.83)	1.09 (0.65–1.82)
Psychosocial variables
MPBIa			1.53 (0.86–2.72)			1.10 (0.83–1.46)
MPSBIb			0.64 (0.10–4.21)			0.93 (0.46–1.88)
Social controls protection			0.61 (0.26–1.46)			0.76** (0.59–1.00)
Individual controls protection			1.29 (0.53–3.15)			0.73** (0.54–0.98)
Social support protection			1.11 (0.39–3.14)			1.09 (0.80–1.50)
Model risk			2.27** (1.14–4.52)			1.03 (0.78–1.35)
Vulnerability risk			1.15 (0.27–4.92)			1.39 (0.81–2.42)
Positive attitudes towards contraception			1.27 (0.41–3.87)			0.70 (0.42–1.18)
Wald χ2	11,001.622***	19,727.065***	10,400.520***	18,609.371***	29,892.313***	33,661.686***
−2Log Likelihood	188.96	162.54	150.16	1122.66	1030.7	1013.24
Subjects (events)	498 (23)	498 (23)	498 (23)	399 (109)	399 (109)	399 (109)
Time at risk	8164.359	8164.359	8164.359	7365.094	7365.094	7365.094

*p<0.1; **p<0.05; ***p<0.01. Models controlled for ethnicity, religion.

^aMultiple Problem Behaviour Index.

^bMultiple Pro-Social Behaviour Index.