Risk of first cervical HPV infection and pre-cancerous lesions after onset of sexual activity: analysis of women in the control arm of the randomized, controlled PATRICIA trial

Table 3 Factors associated with risk of the first CIN1+ or CIN2+ (multivariable Cox proportional-hazards analysis)

Covariate	Category	CIN1+				CIN2+
		No. of women (N = 982)	No. of women with CIN1+ (N = 50)	HR (95% CI)	p-value	No. of women (N = 982)	No. of women with CIN2+ (N = 29)	HR (95% CI)	p-value
Region	Europe	644	35	1		644	21	1
	Asia Pacific	168	6	2.99 (1.03-8.70)	0.0441	168	3	0.76 (0.20-2.93)	0.6942
	Latin America	76	3	1.18 (0.34-4.05)	0.7932	76	1	0.57 (0.07-4.37)	0.5869
	North America	94	6	1.93 (0.80-4.68)	0.1439	94	4	1.73 (0.58-5.18)	0.3238
				0.1480				0.6452
Age at first sexual intercourse	≥18 years	801	41	1		801	26	1
	15-17 years	181	9	0.46 (0.21-1.02)	0.0545	181	3	0.18 (0.05-0.64)	0.0086
				0.0545				0.0086
Number of lifetime sexual partners¹	1	800	9	1		800	5	1
	2-3	537	15	1.73 (0.72-4.15)	0.2213	537	10	1.93 (0.63-5.92)	0.2529
	≥4	245	26	5.60 (2.28-13.77)	0.0002	248	14	4.02 (1.24-13.05)	0.0203
				0.0001				0.0504
Cumulative duration of hormone use for contraception or other indication¹	No use	804	3	1		Not included
	1-12 months	786	13	3.61 (0.94-13.86)	0.0614
	13-48 months	707	32	3.84 (1.00-14.77)	0.0502
	>48 months	102	2	6.09 (0.89-41.63)	0.0653
				0.2157
Tobacco exposure (number of pack-years)¹	<0.5	862	36	1		Not included
	≥0.5	177	14	1.44 (0.76-2.74)	0.2622
				0.2622
Previous cervical HPV infection¹	No	974	2	1		975	1	1
	Yes	431	48	35.70 (8.47-150.50)	<0.0001	432	28	42.30 (5.61-318.63)	0.0003
				<0.0001				0.0003

¹Time-varying covariates. The number of women represents the number of observations that appeared at least once during the follow-up period. One woman can be counted in several categories. The number of events (CIN1+ or CIN2+) corresponds to the value recorded at the most recent visit before the endpoint.
Values in italics are the global p-value.
History of Chlamydia trachomatis (CIN1+ and CIN2+), cumulative duration of hormone use (CIN2+), marital/partner status (CIN1+ and CIN2+) and tobacco exposure (CIN2+) were not included in the multivariable analyses because p-values of >0.2 were obtained in the univariate analyses. The covariates of number of sexual partners during the past 12 months and hormone use or not for contraception or another indication were not included in the multivariable analyses because of overlap with the covariates of number of lifetime sexual partners and cumulative duration of hormone use or other indication, respectively.
CI: confidence interval; CIN: cervical intraepithelial neoplasia; HPV: human papillomavirus; HR: hazard ratio.

ISSN: 1471-2334