Table 3.

Event counts, incidence rates, and incidence rate ratios (95% confidence intervals) for incident cervical cancer by abnormality, follow-up time (years), and histopathology of cancer

	0.5-3.5 years				3.5-6.5 years				6.5-10.5 years				10.5-15.5 years
	No of cases*	IR†	IRR (95% CI)‡		No of cases*	IR†	IRR (95% CI)‡		No of cases*	IR†	IRR (95% CI)‡		No of cases*	IR†	IRR (95% CI)‡
All histopathologies
AGC	73	190.8	24.1 (19.1 to 30.5)		26	79.3	10.0 (6.8 to 14.7)		21	58.7	7.4 (4.8 to 11.4)		12	37.9	4.8 (2.7 to 8.5)
HSIL	178	103.9	13.4 (11.5 to 15.6)		58	40.1	5.1 (4.0 to 6.7)		72	45.4	5.8 (4.6 to 7.3)		63	43.6	5.5 (4.3 to 7.1)
LSIL	347	52.9	6.8 (6.1 to 7.6)		193	35.5	4.5 (3.9 to 5.3)		192	33.2	4.2 (3.7 to 4.9)		168	33.4	4.2 (3.6 to 5.0)
Normal	—	—	Reference		—	—	Reference		—	—	Reference		—	—	Reference
Adenocarcinoma
AGC	53	138.6	60.8 (46.0 to 80.4)		22	67.1	29.0 (19.0 to 44.4)		16	44.7	19.2 (11.7 to 31.5)		7	22.1	9.4 (4.5 to 19.9)
HSIL	25	14.6	6.8 (4.6 to 10.2)		7	4.8	2.2 (1.0 to 4.7)		12	7.6	3.4 (1.9 to 6.0)		11	7.6	3.3 (1.8 to 6.1)
LSIL	44	6.7	3.1 (2.3 to 4.2)		39	7.2	3.3 (2.4 to 4.5)		31	5.4	2.4 (1.7 to 3.4)		30	6	2.6 (1.8 to 3.8)
Normal	—	—	Reference		—	—	Reference		—	—	Reference		—	—	Reference
Squamous cell cancer
AGC	18	47.1	9.1 (5.7 to 14.5)		4	12.2	2.4 (0.9 to 6.3)		4	11.2	2.2 (0.8 to 5.8)		4	12.6	2.5 (0.9 to 6.7)
HSIL	145	84.6	16.3 (13.7 to 19.4)		47	32.5	6.3 (4.7 to 8.4)		57	36.0	7.0 (5.3 to 9.1)		50	34.6	6.7 (5.1 to 8.9)
LSIL	292	44.5	8.6 (7.6 to 9.8)		147	27.1	5.2 (4.4 to 6.2)		151	26.1	5.1 (4.3 to 6.0)		133	26.4	5.1 (4.3 to 6.1)
Normal	—	—	Reference		—	—	Reference		—	—	Reference		—	—	Reference

*No of cases of cervical cancer.

†Observed incidence rate, per 100 000 person years.

‡Incidence rate ratio with 95% confidence interval, relative to women with regular normal cytology, adjusted for attained age.