Table 2. Relative risks (RR) with 95% confidence intervals (95% CI) for cervical intraepithelial neoplasia (CIN3) and cervical cancer (CC) among women with at least five children, by study variables, adjusted for each other.

	CIN3		CC
Variable	RR	95% CI	RR	95% CI
Parity
5	1.00	Ref	1.00	Ref
6	1.03	0.72–1.47	1.08	0.78–1.48
7	0.90	0.54–1.53	1.14	0.72–1.82
8+	0.63	0.36–1.11	0.73	0.44–1.21
Age at first birth (years)
<20	1.00	Refa	1.00	Ref
20–24	0.72	0.51–1.02	0.73	0.51–1.06
25–29	0.54	0.33–0.90	0.66	0.42–1.03
30+	0.57	0.24–1.33	0.65	0.35–1.23
Birth interval (years)
<2.0	1.00	Refb	1.00	Ref
2.0–3.0	0.81	0.58–1.15	0.79	0.57–1.11
3.0+	0.52	0.34–0.81	0.91	0.63–1.33
Age at follow up (years)
<40	0.73	0.39–1.37	2.30	1.27–4.18c
40–49	0.74	0.40–1.37	1.55	0.95–2.52
50–64	0.74	0.42–1.29	1.25	0.87–1.81
65+	1.00	Ref	1.00	Ref

^aTrend P=0.02.

^bTrend P=0.004.

^cTrend P=0.0003.