Abstract
Background. Health disparities are aggravated when prevention and care initiatives fail to reach those they are intended to help. Groups can be classified as hardly reached according to a variety of circumstances that fall into 3 domains: individual (e.g., psychological factors), demographic (e.g., socioeconomic status), and cultural–environmental (e.g., social network). Several reports have indicated that peer support is an effective means of reaching hardly reached individuals. However, no review has explored peer support effectiveness in relation to the circumstances associated with being hardly reached or across diverse health problems.
Objectives. To conduct a systematic review assessing the reach and effectiveness of peer support among hardly reached individuals, as well as peer support strategies used.
Search methods. Three systematic searches conducted in PubMed identified studies that evaluated peer support programs among hardly reached individuals. In aggregate, the searches covered articles published from 2000 to 2015.
Selection criteria. Eligible interventions provided ongoing support for complex health behaviors, including prioritization of hardly reached populations, assistance in applying behavior change plans, and social–emotional support directed toward disease management or quality of life. Studies were excluded if they addressed temporally isolated behaviors, were limited to protocol group classes, included peer support as the dependent variable, did not include statistical tests of significance, or incorporated comparison conditions that provided appreciable social support.
Data collection and analysis. We abstracted data regarding the primary health topic, categorizations of hardly reached groups, program reach, outcomes, and strategies employed. We conducted a 2-sample t test to determine whether reported strategies were related to reach.
Results. Forty-seven studies met our inclusion criteria, and these studies represented each of the 3 domains of circumstances assessed (individual, demographic, and cultural–environmental). Interventions addressed 8 health areas, most commonly maternal and child health (25.5%), diabetes (17.0%), and other chronic diseases (14.9%). Thirty-six studies (76.6%) assessed program reach, which ranged from 24% to 79% of the study population. Forty-four studies (94%) reported significant changes favoring peer support. Eleven strategies emerged for engaging and retaining hardly reached individuals. Among them, programs that reported a strategy of trust and respect had higher participant retention (82.8%) than did programs not reporting such a strategy (48.1%; P = .003). In 5 of the 6 studies examining moderators of the effects of peer support, peer support benefits were greater among individuals characterized by disadvantage (e.g., low health literacy).
Conclusions. Peer support is a broad and robust strategy for reaching groups that health services too often fail to engage. The wide range of audiences and health concerns among which peer support is successful suggests that a basis for its success may be its flexible response to different contexts, including the intended audience, health problems, and setting.
Public health implications. The general benefits of peer support and findings suggesting that it may be more effective among those at heightened disadvantage indicate that peer support should be considered in programs intended to reach and benefit those too often hardly reached. Because engendering trust and respect was significantly associated with participant retention, programs should emphasize this strategy.
PLAIN-LANGUAGE SUMMARY
Health programs sometimes fail to reach those they intend to help, which contributes to health disparities. We reviewed research on the effectiveness of peer support among individuals too often hardly reached, identified via individual (e.g., psychological distress), demographic (e.g., ethnic minority), and environmental (e.g., rural) characteristics. Peer support refers to emotional, social, and practical assistance provided by nonprofessionals to encourage behaviors such as healthy diets or medication adherence. Although previous research has noted the benefits of peer support among those hardly reached, no review has explored peer support across the circumstances associated with being hardly reached.
Of the 47 studies reviewed here, 94% reported significant changes favoring peer support. Furthermore, peer support was effective across varied health topics (e.g., maternal and child health, diabetes, HIV/AIDS) and circumstances related to being hardly reached. Interventions engaged 55.1% of those who agreed to participate and retained 78.6% of participants. Retention was greater among interventions emphasizing trust and respect. Peer support was more effective among those with disadvantages such as low health literacy. Peer support is a broad and robust approach to reaching and benefiting those too often hardly reached. The breadth of circumstances in which it is effective suggests that flexibility is a contributor to its success.