Peers have intervened to promote health since ancient times, yet few attempts have been made to describe theoretically their role and their interventions. After a brief overview of the history and variety of peer-based health interventions, a 4-part definition of peer interveners is presented here with a consideration of the dimensions of their involvement in health promotion. Then, a 2-step process is proposed as a means of conceptualizing peer interventions to promote health. Step 1 involves establishing a theoretical framework for the intervention’s main focus (i.e., education, social support, social norms, self-efficacy, and patient advocacy), and Step 2 involves identifying a theory that justifies the use of peers and might explain their impact. As examples, the following might be referred to: theoretical perspectives from the mutual support group and self-help literature, social cognitive and social learning theories, the social support literature, social comparison theory, social network approaches, and empowerment models.

Behavioral interventions to prevent HIV or assist HIV-positive persons often incorporate peers, yet empirical support for their efficacy is only recently accumulating. We describe the results of a review of the global literature, identifying 117 studies evaluating the efficacy of peer-based interventions in the area of HIV/AIDS. About half were conducted in the developing world and half in Western nations. Across a range of populations and intervention modalities, the majority of studies provided some support for peer interventions according to outcome indicators in the domains of sexual risk behavior, attitudes and cognitions, HIV knowledge, and substance use. However, outcomes assessed using biomarkers and other non-self-report variables were less likely to indicate intervention efficacy. Overall, findings suggest that we can have some confidence in peer interventions, yet more data are needed demonstrating an effect in the most rigorous study designs and with outcomes that are not potentially affected by respondent bias.

The HPTN 067/Alternative Dosing to Augment Pre-Exposure Prophylaxis Pill Taking (ADAPT) study evaluated daily and non-daily dosing schedules for oral pre-exposure prophylaxis (PrEP) to prevent HIV. A qualitative sub-study including focus groups and in-depth interviews was conducted among men who have sex with men participating in New York City to understand their experience with PrEP and study dosing schedules. The 37 sub-study participants were 68% black, 11% white, and 8% Asian; 27% were of Hispanic/Latino ethnicity. Mean age was 34 years. Themes resulting from qualitative analysis include: PrEP is a significant advance for HIV prevention; non-daily dosing of PrEP is congruent with HIV risk; and pervasive stigma connected to HIV and risk behavior is a barrier to PrEP adherence, especially for non-daily dosing schedules. The findings underscore how PrEP intersects with other HIV prevention practices and highlight the need to understand and address multidimensional stigma related to PrEP use.

Literature describing the roles and activities of peers working in HIV care is limited. Evaluations of the impact of peer-based behavior-change interventions reveal mixed results, due in part to varied program aims, structure, evaluation mechanisms, and training. Peers themselves are important resources to address these concerns and lay the groundwork for developing improved programs and evaluation strategies. This qualitative article describes peer support in HIV care and treatment from the perspective of 23 HIV-positive peers across the United States. Peers reported that peer characteristics (HIV-status, common experiences, and self-care) enable them to engage clients. Peers also required flexibility to respond to client needs, and their activities spanned four types of social support: informational, emotional, instrumental, and affiliational. We recommend peer programs and evaluations accommodate the broad scope of peer work by acknowledging the need for flexibility and activities that are not always directly related to clients' HIV care and treatment.