Implementing a National Registry of Patients with Inborn Errors of Immunity in Peru: A Mixed-Methods Protocol

BackgroundInborn errors of immunity (IEIs) include more than 500 genetic disorders that cause recurrent infections, autoimmunity, and inflammatory complications. Although classified as rare diseases, their prevalence is increasing, making IEI an emerging public health problem. However, reliable national epidemiological data and coordinated follow-up data of IEI patients are lacking, which potentially affects up to 20,000 people in Peru. ObjectiveIn this study, we aim to describe the protocol of a three-phase mixed-method study that will design, build, and evaluate the usability and feasibility of the first Peruvian National IEI Registry. MethodsGuided by the Exploration-Preparation-Implementation-Sustainment (EPIS) framework, Phase I (qualitative) will map stakeholder needs through in-depth interviews and focus groups; the data will undergo hybrid thematic analysis in ATLAS.ti. Phase II (pre-experimental) will enroll [≥]20 clinical immunology consultants and residents to complete standardized tasks on the REDCap-based prototype; efficiency (task time), effectiveness (error rate), and satisfaction will be compared pre/post-iteration. Phase III (observational) will assess feasibility by enrolling [≥]126 IEI cases across six national reference hospitals; the primary outcomes are clinical profile, data completeness, and accuracy. ResultsThe study protocol received institutional review board approval in February 2025 from the UNMSM-Research Ethics Committee. Phase I enrollment started in March 2025. We expect our REDCap-based prototype to incorporate key needs and preferences gathered from focus groups and interviews to develop the platform. By the completion of the study phase II, we will have assessed the usability of the prototype platform. Study phase III will begin in April 2026. The final results are expected by November 2026 and will be published thereafter. ConclusionsBy evaluating usability and feasibility in real-world conditions, this protocol lays the groundwork for a national IEI registry. The resulting evidence will inform scale-up decisions and facilitate its incorporation into Peruvian health policy. Contributions to the literature- Shows how the EPIS framework can steer real-world adoption of a REDCap-based registry and prospectively measure usability and feasibility across six public hospitals involved in rare-disease surveillance. - Provides a mixed-methods protocol that designs, iterates and field-tests Perus first national registry for inborn errors of immunity, tackling persistent barriers to rare-disease data capture in low- and middle-income countries and offering a scalable blueprint for other resource-constrained settings. - Outlines a FAIR-aligned governance and data-sharing strategy that can be adapted by future programmes planning registries for rare and orphan diseases in similar contexts.