GAP2POP as a complementary hierarchical framework for aligning knowledge gaps, health priorities, evidence generation, and population influence-impact

Background Health research evaluation frameworks rarely integrate the identification of knowledge gaps and health needs, the definition of health priorities, evidence generation, the monitoring of population indicators, and the assessment of knowledge translation and population influence and impact within a single model. This structural absence lets research agendas drift from population needs, evidence be produced without correspondence to measurable health indicators, and the link between scientific knowledge and health outcomes remain unexamined. Methods We conceptually developed GAP2POP, a six-level hierarchical framework, through a narrative synthesis integrating principles from epidemiology, evidence-based medicine, implementation science, meta-research, and responsible research evaluation. The framework was designed to serve as both an evaluative tool, for auditing existing research portfolios, and a normative tool, for guiding future ones. Results GAP2POP organizes the research-to-outcome pathway into six hierarchical, bidirectional levels: identification of knowledge gaps and health needs, definition of health priorities, evidence generation, epidemiological outcome monitoring, knowledge translation and implementation, and assessment of population influence and impact. Each level has distinct conceptual functions, operational indicators, and methodological requirements, preventing the collapse of analytically distinct phenomena into one undifferentiated judgment of research value. The framework’s central contribution is a formal distinction between influence, the epistemic and discursive repercussion of research on scientific communities, clinical practice, or health policy without requiring causal demonstration of outcome modification, and impact, the causally attributable and demonstrable modification of a health outcome in a defined population. GAP2POP also identifies four categories of scientific incoherence, foundational, translational, implementational, and causal, that existing frameworks do not capture. Conclusions GAP2POP offers a complementary framework for aligning health research with population needs and evaluating research value with greater precision. By distinguishing influence from impact and locating where coherence breaks down along the research-to-outcome pathway, it may help investigators, funders, and health systems design and assess research agendas.