. Author manuscript; available in PMC: 2019 Apr 1.

Published in final edited form as: J Acquir Immune Defic Syndr. 2018 Apr 1;77(4):358–364. doi: 10.1097/QAI.0000000000001604

Table 5.

Effects of PrEP Use on Condomless Anal Sex in Cohort HIV-Positive Serodiscordant Partnerships

Outcome	Predictor	IRR	Confidence Interval (95%)	p-value
Insertive sex	Partner on PrEP	2.3	1.3 – 4.05	0.004

Insertive CAS	Partner on PrEP	1.66	0.81 – 3.4	0.17

Receptive sex	Partner on PrEP	1.97	1.19 – 3.26	0.008

Receptive CAS	Partner on PrEP	0.41	0.11 – 1.58	0.194
Receptive CAS	Partner on PrEP*Serious	14.27	2.62 – 77.56	0.002

Total anal sex	Partner on PrEP	1.51	1.07 – 2.13	0.018

Total CAS	Partner on PrEP	1.75	0.9 – 3.38	0.097

NOTE: Cohort HIV-positive serodiscordant refers to partnerships in which the participant is HIV-positive and the partner is perceived HIV-negative/unknown. Partner on PrEP*Serious refers to the interaction between partner PrEP status and relationship type (serious vs. non-serious). PrEP = pre-exposure prophylaxis; IRR = incidence-rate ratio; CAS = condomless anal sex.