Table 1 Definition of terms

Realist methodology. A theory driven, interpretative approach to uncovering underlying middle-range theories (or logics) driving interventions and their multiple components, as well as illuminating the contextual factors that influence mechanisms of change to produce outcomes.

Middle-range theory (MRT): an implicit or explicit explanatory theory that can be used to explain specific elements of programs or how program logic manifests in implementation. “Middle-range” means that it can be tested with the observable data and is not abstract to the point of addressing larger social or cultural forces (i.e., grand theories). MRT is sought at the outset and examined iteratively throughout the review.

Context-mechanism-outcome (CMO) configurations: CMO configuring is a heuristic used to generate causative explanations about outcomes in the observed data. A CMO configuration may be about the whole program or only to certain aspects. One CMO may be embedded in another or configured in a series (ripple effect in which the outcome of one CMO becomes the context for the next in the chain of implementation steps). Configuring CMOs is a basis for generating and/or refining the theory that becomes the final product of the review.

Context: Context often pertains to the “backdrop” of programs and research. For example, in our review of CBPR, it covers the conditions connected to the development of research partnerships. As these conditions change over time, the context may reflect aspects of those changes while the program is implemented. Examples of context include cultural norms and history of the community in which a program is implemented, the nature and scope of existing social networks, or built program infrastructure. They can also be trust-building processes, geographic location (e.g., rural or urban), types of funding sources, and other opportunities or constraints.

Mechanism: the intended or unintended resources created by an intervention and the response to those resources (cognitive, emotional, motivational etc) by participants. Mechanisms can pertain to why participants choose (or choose not) to participate in interventions or internalize health knowledge or behavior change from the intervention. It may also be applied to other ‘actors’ such as implementers and staff. Mechanisms are not synonymous with strategies (e.g., a strategy may be an intended plan of action, whereas a mechanism involves the resource create by the strategy + the participants’ reaction or response to the intentional offer of incentives, disciplinary actions, or other resources).

Outcomes and effects: Our interest in evaluating CBPR outcomes is not only in assessing intended outcomes (did the project succeed against the criteria it set itself at the outset), but also all the intermediate outcomes as well as unplanned and/or unexpected impacts, of which we have noted many. These are important because unplanned outcomes can sometimes have a greater influence on the determinants of health for a community than the more narrowly focussed outcome goals of projects. Furthermore, unintended impacts may have ‘ripple effects’ [42] in that they lead to new effects which then lead to more effects, thus changing the context of research overtime. The realist methodology used here is particularly suited to capturing these ripple effects in linked context-mechanism-outcome (CMO) configurations, depicted in Fig. 1.