Table 4.

Categorization into the continuum of implementation [17]

	N	%	Articles
Proof of Concept Studies where implementation is not relevant or is relevant but not considered as research questions. The context of these studies is controlled and the factors affecting implementation are not relevant, fixed, or ignored Examples: Basic science, Phase I, II, & III clinical tr ials, efficacy studies, qualitative studies that are non-implementation or consider service quality	20	39.2	[13, 28, 31, 36, 39, 44–46, 48, 51, 52, 54, 56, 57, 60, 61, 64, 67, 72, 74]
Proof of Implementation Implementation variables are relevant but the effects are reduced. The context is real world with some control to intervention. Single implementation strategy. Implementation variables are equal or unchanging Examples: Pragmatic trials, Quasi-experimental, Observational studies with Implementation as secondary aim	13	25.5	[25, 27, 32, 33, 35, 38, 40, 42, 55, 63, 66, 71, 73]
Informing Scale-up Emphasize health system integration and sustainability as principal consideration. In these studies, implementation science contributed significantly or was the primary focus in the development of the research questions. Various methodologies may be used, such as participatory research, mixed methods, or observational studies, but implementation variables are either primary outcomes or independent variables  Examples: Effectiveness implementation trials, participatory research, Mixed methods or quasi-experimental studies evaluating changes in delivery or acceptability, Observational studies with implementation as secondary factors or focused on adaptation, learning, and program scaling	18	35.3	[26, 29, 30, 34, 37, 41, 43, 47, 49, 50, 53, 58, 59, 62, 65, 68–70]