Table 4.

Multivariable Models of Time-Varying Hormonal Contraception and Time to Human Immunodeficiency Virus (HIV) Infection Among Zambian Men in HIV-Discordant Relationships

Primary Model	aHR (95% CI)	P Valuea
Contraceptive method
Nonhormonalb	Reference
OCPs	0.84 (.34–2.13)	.72
Injectables	0.64 (.35–1.16)	.14
Implant	0.83 (.50–1.38)	.46
Sensitivity analyses
Model controlling for woman's viral loadc
Nonhormonalb	Reference
OCPs	0.99 (.38–2.57)	.98
Injectables	0.65 (.35–1.21)	.17
Implant	0.92 (.55–1.54)	.92
Model controlling for man's fertility intentionsc
Nonhormonalb	Reference
OCPs	0.59 (.14–2.56)	.48
Injectables	0.48 (.20–1.18)	.11
Implant	0.81 (.39–1.65)	.55
Model censoring at first method switch
Nonhormonalb	Reference
OCPs	0.51 (.12–2.13)	.36
Injectables	0.67 (.34–1.33)	.26
Implant	0.87 (.47–1.60)	.65
Model limited to no self-reported condom use (only condomless sex intervals)
Nonhormonalb	Reference
OCPs	0.92 (.28–3.07)	.90
Injectables	0.68 (.31–1.46)	.32
Implant	0.76 (.37–1.59)	.47
Marginal structural modelse
Nonhormonalb	Reference
OCPs	0.96 (.47–1.99)	.92
Injectables	0.72 (.32–1.62)	.43
Implant	1.68 (.52–5.45)	.39

Abbreviations: OCP, oral contraceptive pill; aHR, adjusted hazard ratio; CI, confidence interval; VL, viral load.

^a Data are 2-tailed.

^b Includes couples using condoms alone, the copper intrauterine device, or permanent methods.

^c Models controlling for woman's viral load were run among the subset of couples tested from 1999–2012; models controlling for man's fertility intentions were run among the subset of couples tested between 2002–2011.

^d Controlling for man's age, pregnancy, any self-reported unprotected sex with study partner in the last 3 months, sperm present on vaginal swab wet mount, genital inflammation in man or woman in the past 3 months, genital ulceration of man in past 3 months, and interval of enrollment (0–3 vs >3 months).

^e Controlling for man's age, male circumcision status, and interval of enrollment (0–3 months vs >3 months).