Research Studies

• Level 1 (baseline, simple epidemiology): baseline registry data export analyses of already existing (routinely captured) data for, e.g., cross-sectional epidemiological studies or to locate patients with ultrarare diseases for add-on studies. If retrospective longitudinal data are needed (field histories), these will need to be provided by Castor-edc on a designated service order. Example: Initial manifestations of IEI.
• Level 2 (add-on, e.g., limited longitudinal data capture): Sub-studies typically limited to specific disease categories, diagnoses, or geographically, with an add-on CRF (either in Castor-edc or hybrid), often prospective disease-specific data collections or surveys. Example: HLH-Registry.
• Level 3 (add-on, separate study protocol-based prospective observational study): Larger sub-studies with a clear study endpoint and duration, limited to specific, mostly monogenically defined diseases; often pharma-sponsored. New: may also be designed to serve as registry-based post-authorization efficacy and safety (PAES) study. Example: APDS Study.

Evaluation of Study Proposals

Each submitted study proposal is first reviewed by the Registry Chairperson to ensure completeness, after which it is forwarded to the Steering Committee (SC; see the Registry Working Party main page) for evaluation. The SC is composed of six experts in the field of IEI/PID and clinical research from diverse countries and professional backgrounds, together with the Chairperson. The committee meets regularly and aims to provide feedback within 2–4 weeks of submission.

The primary purpose of the review is to assess proposals for potential redundancies—helping to prevent duplicate or overlapping studies within the ESID registry—and to evaluate the overall feasibility of the proposed project. Please note that the SC does not assess the scientific merit or novelty of the study idea itself, and that responsibility for defining the study scope, ensuring proper conduct, and maintaining ethical and legal compliance with the ESID registry protocol rests entirely with the study’s principal investigator or research group.

Before developing a detailed study proposal, we strongly encourage applicants to review the ESID Level 1 (baseline) dataset. It is also important to be aware that data from the annually recommended patient follow-up visits may not always be complete or up to date.