Table 3.

 Ten year hazard ratios of developing cervical cancer after negative follow-up test results following histologically confirmed cervical intraepithelial neoplasia, by age group

Age (years) at primary smear test	Woman years at risk	No of cases	Hazard ratio* (95% CI)
≤29	12 579	6	5.2 (2.3 to 11.7)
30 to 49	39 165	12	3.2 (1.8 to 5.6)
≥50	5212	2	6.8 (1.7 to 27.3)
Total	56 956	20	4.2 (2.7 to 6.5)

*Compared with normal primary smear test results (see tables 1 and 2). Corrected for year in follow-up.