**4. Methodology of the conceptual framework**

The conceptual framework (CF) was developed by conceptualizing the two stages of the study—The impact of NIMART training on HIV management and barriers to NIMART Training and Implementation. An explanatory sequential mixed method (QUAN-qual) was used [7]. Mixed methods refer to a research strategy in which a researcher combines qualitative and quantitative methods to comprehensively understand the phenomenon under study to produce a more complete and validated conclusion [8–10]. In order to develop a conceptual framework that will provide direction, strengthen NIMART training and implementation, and improve patient outcomes, a descriptive and explorative program evaluation design was used. Retrospective data were gathered from the District Health Information System (DHIS) and the three integrated electronic registers (TIER.NET), of the selected PHC facilities, including interviews with purposively selected NIMART-trained nurses and program managers directly involved in managing TB/HIV coinfection until data saturation was reached. Programme evaluation research refers "to an applied system scientific method used to measure or assess the implementation, conceptualization, design, utility and outcomes or impact of social programs for decision making purpose", and is very useful in mixed methods [11, 12].

The Donabedian structure-process-outcome (SPO) model and Dickoff, James, and Wiedenbach's practice-oriented theory were two models that were crucial in the creation of the theoretical lens through which this conceptual framework was developed. The Donabedian's SPO model gave the researcher a framework to assess and enhance the application of HIV management following NIMART training [13]. The structure of the fixed PHC facilities providing ART or health care system and the process of NIMART training to professional nurses greatly influence the achievement of the health outcomes. Furthermore, following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses, a thorough review of the literature was conducted in studies conducted in Africa and around the world from January 2012 to February 2017 from various databases. The results were analyzed using the quality assessment research instrument created by the Joan Briggs Institute in 2014 to obtain a broader perspective of factors that can enable and those that can be a barrier to NIMART training and implementation and play a major role in the development of the conceptual framework. Studies consulted for the thorough literature review revealed positive and negative factors affecting NIMART training and implementation. These will be discussed in detail in section five as barriers and enablers to efficient NIMART training and implementation, together with study findings.

The final conceptual framework was developed following Dickoff et al.'s POT, with six elements presented as questions and integrated into Donabedian's SPO model [14], as presented in **Figure 1**. The six elements questions addressed include:
