Table 2.

Stepwise quasipoisson mixed-effects incident risk ratios (IRR) estimates of 6-month unprotected anal intercourse (UAI) episodes within male–male partnerships

	Model 1			Model 2
	IRR	(95 % CI)	p	IRR	(95 % CI)	p
(Intercept)	0.23	(0.12, 0.44)	0.000	0.85	(0.13, 5.14)	0.857
Dyadic
Anal episodes	1.02	(1.02, 1.03)	0.000	1.02	(1.02, 1.02)	0.000
Partner is a ‘regular’ partner	1.78	(1.41, 2.24)	0.000	1.81	(1.43, 2.28)	0.000
Number of months sexual	1.24	(1.15, 1.33)	0.000	1.23	(1.14, 1.33)	0.000
Partner age difference	1.01	(0.99, 1.03)	0.210
Sexual positioning (ref = both)
Receptive	0.54	(0.33, 0.88)	0.015	0.51	(0.31, 0.84)	0.009
Insertive	0.97	(0.63, 1.50)	0.898	0.89	(0.58, 1.37)	0.597
Extra-dyadic
Proportion of months concurrent with other partners (ref = 0)
(0, 0.75]	1.28	(0.91, 1.81)	0.155
(0.75, 1]	1.04	(0.74, 1.44)	0.835
Unknown	1.03	(0.33, 3.17)	0.959
Has a regular female partner	0.88	(0.56, 1.37)	0.562
Has a regular male partner	1.40	(0.83, 2.36)	0.562
Total male and female partners (6 months)	1.03	(1.00, 1.06)	0.037	1.02	(0.99, 1.05)	0.156
Individual
Number of close MSM friends				1.00	(1.00, 1.00)	0.291
Internalized homonegativity				1.18	(0.59, 2.37)	0.635
Experiences of homonegativity				3.98	(1.04, 15.26)	0.044
Sexual identity (ref = gay)
Bisexual/down-low				0.84	(0.49, 1.45)	0.540
Straight				0.69	(0.36, 1.31)	0.254
Social norms				0.96	(0.44, 2.09)	0.926
Safer sex self-efficacy				0.15	(0.07, 0.29)	0.000
Years of schooling				0.99	(0.90, 1.09)	0.790
Income ≤ZAR500/month				0.61	(0.40, 0.93)	0.021
Age				1.02	(0.98, 1.06)	0.318
Circumcised (ref. not circumcised)				1.86	(1.27, 2.73)	0.002
HIV status at enrollment (ref. prior negative)
Prior positive				0.82	(0.37, 1.80)	0.620
Never tested, negative				1.19	(0.74, 1.92)	0.476
Never tested, positive				1.14	(0.59, 2.21)	0.698
No HIV test				1.04	(0.56, 1.95)	0.894
var (intercept)		1.547			1.055
var (residual)		2.439			1.699
IQR (standardized within-individual residual)		(−0.49, −0.05)			(−0.47, −0.04)