Table 3. Adjusted relative hazards of HIV seroconversion (with condoms) among North American men who have sex with men from four longitudinal cohort studies, 1995–2007.

				Model with No UAI as reference		Model with Highest risk sex as reference
Risk category	Visits N (%)	HIV SC* (N)	SC per-cent	Adjusted HR**	95% CI	Adjusted HR	95% CI
No UAI	28316 (47.6)	173	0.61	reference	n/a	0.24	0.19–0.29
Single negative partner	6393 (10.8)	16	0.25	0.57	0.33–0.98	0.14	0.08–0.24
Unprotected top	9459 (15.9)	58	0.61	0.79	0.58–1.07	0.19	0.14–0.25
Condom serosorting	6287 (10.6)	88	1.38	1.82	1.39–2.37	0.43	0.34–0.55
Condom seropositioning	1357 (2.3)	25	1.81	1.86	1.21–2.86	0.44	0.29–0.67
Highest risk sex	7680 (12.9)	303	3.80	4.20	3.42–5.15	reference	n/a

^*seroconversion.

^**adjusted for age, race, number of sexual partners, and any methamphetamine and popper use in the last six months, and intervention assignment.

## models are equivalent except for using different groups as the reference category.