Table 3.

Risk of CIN 2 and CIN 3+ diagnosed following detection of prevalent carcinogenic human papillomavirus (HPV) infections by screening density and age groups, excluding CIN 2 and CIN 3+ diagnosed at enrollment^*

Screening group	Age group, y†	Infections followed, No.‡	Incident CIN 2 diagnosis, No. (%)	Incident CIN 3+ diagnosis, No. (%)	Total incident CIN 2+, No. (%)
Active follow-up of prevalent infections§	18–25	259	8 (3.1)	10 (3.9)	18 (7.0)
	26–33	189	4 (2.1)	8 (4.2)	12 (6.4)
	34–41	106	2 (1.9)	7 (6.6)	9 (8.5)
	≥42	211	2 (1.0)	17 (8.1)	19 (9.0)
Passive follow-up of prevalent infections‖	18–25	90	0 (0.0)	0 (0.0)	0 (0.0)
	26–33	98	1 (1.0)	2 (2.0)	3 (3.1)
	34–41	56	1 (1.8)	2 (3.6)	3 (5.4)
	≥42	119	1 (0.8)	1 (0.8)	2 (1.7)

^*CIN = cervical intraepithelial neoplasia (grade 2 or 3 or higher). Of the 142 CIN 2+ censored at enrollment the distribution for the four age groups is 15, 47, 35, and 45.

^†Age at time of first detection of the carcinogenic HPV infection.

^‡Regardless of follow-up time.

^§Six cancers, 1, 1, 1, 3 by age group (one cancer from woman aged 42+ y who was HPV negative). One CIN 2 assigned to two persisting carcinogenic HPV infections (1, 0, 0, 0), and seven CIN 3 assigned to 13 persisting carcinogenic HPV infections (one had both a prevalent and newly detected persistent infection) (3, 1, 0, 3).

^‖Three cancers, 0, 1, 1, 1 by age group (one cancer from woman aged 42+ y who had a newly detected carcinogenic infection). No cases of multiple persisting carcinogenic HPV infections at the time of CIN 2+ diagnosis.