Adaptation Model for Patient and Caregiver Dyads in Hospital-to-Home Transition: Theory Development and Content Validation.

Background/Objective: The H-HT represents a critical vulnerability for patient-family caregiver dyads. This study developed and content-validated a middle-range nursing theory, the Adaptarte Model, designed to guide dyadic adaptation during the H-HT within the Latin American healthcare context. Methods: A sequential exploratory multimethod design was executed in two phases. Phase 1 integrated three evidence streams: clinical practice insights, a JBI-guided scoping review, and two focus groups with transitional care professionals. Qualitative content analysis and iterative consensus refined the model's core concepts, assumptions, and propositions. Phase 2 evaluated the model's content, structure, functionality, and projection using an international panel of eleven Latin American experts meeting strict eligibility criteria. Data were analyzed using Lawshe's Content Validity Ratio (CVR) modified by Tristán (cutoff = 0.58) and the overall Content Validity Index (CVI). Reporting followed PRISMA-ScR and GRAMMS guidelines. Results: Expert consensus confirmed the essential model components. Item-level CVR values ranged from 0.90 to 0.99, yielding an overall CVI of 0.96, while external functionality and conceptual projection achieved an average rating of 0.88. Conclusions: The Adaptarte Model demonstrates high content validity and structural clarity, establishing a rigorous theoretical foundation for subsequent empirical research. Rather than being ready for immediate clinical implementation, it provides a structured blueprint for prospective protocol development. Systematic empirical testing and longitudinal studies are now imperative to evaluate its clinical utility and drive future healthcare transformations. The scoping review protocol was prospectively registered on the Open Science Framework (OSF) URL (accessed on 23 September 2024).