BackgroundDespite the availability of practical knowledge and effective interventions required to reduce priority health problems in low-income countries, poor and vulnerable populations are often not reached. One possible solution to this problem is the use of Community or Lay Health Workers (CLHWs). So far, however, the development of sustainability in CLHW programs has failed and high attrition rates continue to pose a challenge. We propose that the roles and interests which support community health work should emerge directly from the way in which health is organized at community level. This review explores the evidence available to assess if increased levels of integration of community health resources in CLHW programs indeed lead to higher program effectiveness and sustainability.Methods and FindingsThis review includes peer-reviewed articles which meet three eligibility criteria: 1) specific focus on CLHWs or equivalent; 2) randomized, quasi-randomized, before/after methodology or substantial descriptive assessment; and 3) description of a community or peer intervention health program located in a low- or middle-income country. Literature searches using various article databases led to 2930 hits, of which 359 articles were classified. Of these, 32 articles were chosen for extensive review, complemented by analysis of the results of 15 other review studies. Analysis was conducted using an excel based data extraction form. Because results showed that no quantitative data was published, a descriptive synthesis was conducted. The review protocol was not proactively registered. Findings show minimal inclusion of even basic community level indicators, such as the degree to which the program is a community initiative, community input in the program or training, the background and history of CLHW recruits, and the role of the community in motivation and retention. Results show that of the 32 studies, only one includes one statistical measure of community integration. As a result of this lack of data we are unable to derive an evidence-based conclusion to our propositions. Instead, our results indicate a larger problem, namely the complete absence of indicators measuring community relationships with the programs studied. Studies pay attention only to gender and peer roles, along with limited demographic information about the recruits. The historicity of the health worker and the community s/he belongs to is absent in most studies reviewed. None of the studies discuss or test for the possibility that motivation emanates from the community. Only a few studies situate attrition and retention as an issue enabled by the community. The results were limited by a focus on low-income countries and English, peer-reviewed published articles only.ConclusionPublished, peer-reviewed studies evaluating the effectiveness and sustainability of CLHW interventions in health programs have not yet adequately tested for the potential of utilizing existing community health roles or social networks for the development of effective and sus...