OBJECTIVE:

We evaluated the relationship between two types of social relationships (i.e., 1) external support for use of HIV pre-exposure prophylaxis [PrEP] and related study supplies 2) participants’ disclosure of PrEP use and condom use and HIV PrEP adherence among daily-dosing regimen participants in HPTN 067, an open-label trial of oral tenofovir (TFV) disoproxil fumarate (TDF) 300 mg/emtricitabine (FTC) 200 mg.

METHODS:

Using HPTN-067 survey data, we developed scales examining 1) Low Perceived External Support for PrEP: low perceived support by others for PrEP use or perceived negative reactions to the pill case (scoring ranges from 0 to 2) and 2) Participant-Staff Disclosure Challenges Scale which identifies challenges to sharing non-use of PrEP or condoms to study staff (scoring ranges from 0 to 4); these scales are the primary independent variables. Adherence, the dependent variable, was determined using log-transformed plasma TFV concentrations. GEE linear regression was used to assess the association between both scales and adherence.

RESULTS:

Participants (n=161) included HIV-uninfected women in South Africa, and men who have sex with men and transgender women, in Thailand and the U.S. In multivariable analyses, higher scores in the Participant-Staff Disclosure Challenges Scale were significantly associated with lower PrEP adherence (exp(β) = 0.62, 95% CI (0.46- 0.84); p=0.002) as were increased days since the last PrEP dose (exp(β) = 0.73, 95% CI (0.65- 0.83); p≤0.001).

CONCLUSIONS:

Given the association with adherence, study staff-participant interactions and participants’ disclosure of PrEP challenges may be worthwhile intervention targets for improving PrEP adherence in confirmatory studies.

Photo caption: A transgender woman in a hospital gown being treated by a doctor, a transgender man. (Zackary Drucker for the Gender Spectrum Collection)