Designing a provider-led multimorbidity care model for fragmented insurance-based health systems: A mixed-methods study in Colombia.

Multimorbidity the coexistence of two or more chronic conditions is a growing challenge for health systems in low- and middle-income countries (LMICs) structured around single-disease paradigms. In Colombia, insurer-provider fragmentation within the General System of Social Security in Health (SGSSS) compounds this challenge, generating discontinuities in care that disproportionately affect people living with multiple chronic conditions. Despite a national epidemiological characterisation, a World Bank-supported management proposal, and a formal pilot implementation, limited published evidence exists of a sustained, provider-level, evidence-grounded model for multimorbidity care in fragmented, insurance-based systems. A sequential exploratory mixed-methods design was employed, comprising three phases: (1) a structured evidence synthesis to identify operational domains and implementation gaps in multimorbidity care models; (2) evidence-informed conceptual model construction; and (3) expert feasibility consultation using elements of the Nominal Group Technique with healthcare professionals and system stakeholders (n = 11). Phases were sequentially integrated, with each informing the development of the next. Evidence synthesis identified five recurring structural domains and four cross-cutting implementation gaps, which together informed the construction of the Integrated Provider-level Adaptive Multimorbidity Model (IPAM). The IPAM comprises five interdependent provider-level components designed to function within fragmented, insurance-based systems. Expert consultation confirmed operational feasibility (mean 4.3/5), clinical relevance (4.7/5), and territorial adaptability (4.6/5) of the proposed model. The IPAM offers a structured, adaptable conceptual framework for strengthening multimorbidity care within provider institutions (IPS) operating in fragmented, insurance-based health systems. Its core design principles minimum-viable risk stratification, provider-level governance, proactive follow-up, and graduated technology integration - are transferable to analogous LMIC contexts. Prospective implementation and cost-effectiveness evaluation represent the essential next phase of validation.