Objective: Dual threats of injection drug use and risky sexual practices continue to increase transmission of HIV and other sexually transmitted Infections (STIs) among drug-using couples in low-income communities in the United States. Two hypotheses were tested: (1) "intervention effect"-whether the HIV risk-reduction intervention provided to the couple or individual partners would be more efficacious in decreasing number of unprotected sexual acts and having a lower cumulative incidence of biologically confirmed STIs over the 12-month follow-up period compared with the attention control condition; and (2) "modality effect"-whether the HIV risk-reduction intervention would be more likely to decrease the number of unprotected sexual acts and have a lower cumulative STI incidence when delivered to a couple compared with the same intervention delivered to an individual.
Design: Using a randomized controlled trial, 282 HIV-negative drug-using couples (564 individuals) were randomly assigned to receive either of the following: (1) couple-based risk reduction; (2) individual-based HIV risk reduction, or (3) couple-based wellness promotion, which served as an attention control condition.
Results: Over 12-month follow-up, there was a 30% reduction in the incidence rate of unprotected acts of intercourse with the study partners compared with participants in the attention control arm. Moreover, over 12-month follow-up there was a 29% reduction in the same outcome in the couple arm compared with the individual arm with a 41% reduction at the 12-month follow-up.
Conclusion: A couple-based approach that addresses drug and sexual risks and targets low-income active drug users may help curb the HIV epidemic.