Stakeholder Perspectives on Affinity Domains in Digital Health Interoperability: Qualitative Study.

Background: Operational health data interoperability in post-transition health systems requires not only technical standards but also enforceable governance arrangements. Affinity domains, as defined in the IHE XDS (Integrating the Healthcare Enterprise Cross-Enterprise Document Sharing) framework, represent a structured organizational-technical model for cross-enterprise document sharing. However, evidence from Central and Eastern Europe on their governance feasibility and implementation readiness remains limited, particularly in systems characterized by institutional fragmentation and evolving regulatory mandates. Objective: This study aimed to examine stakeholder perceptions of the prerequisites, risks, benefits, and governance conditions for implementing affinity domains in the Czech health care system. The study further sought to identify system-level readiness factors relevant to national interoperability initiatives in the context of the European Health Data Space regulation. Methods: We conducted 18 semistructured interviews between January 2025 and April 2025 with policymakers, regional health authorities, health care providers, health insurance funds, health IT vendors, and independent experts. Participants were selected using purposive and snowball sampling to ensure institutional diversity. Interviews explored governance roles, legal accountability for shared data, enforcement of standards, financing models, and technical readiness. Data were analyzed inductively using thematic analysis in MAXQDA 24 (VERBI Software GmbH), supported by dual coding, consensus discussions, and reflexive memoing. Inductively derived themes were subsequently interpreted against core governance dimensions of affinity domains (rule-making authority, membership and participation, accountability, enforcement, and trust). Results: Five major thematic categories emerged: (1) ambiguous roles and responsibilities marked by fragmented mandates and vendor influence; (2) perceived risks, including institutional distrust, legal uncertainty regarding liability, technical fragmentation, and vendor lock-in; (3) system-level prerequisites such as the need for an empowered coordinating authority, binding interoperability standards (IHE XDS and HL7 FHIR [Health Level 7 Fast Healthcare Interoperability Resources]), sustainable financing, and human resource capacity; (4) perceived benefits, including improved continuity of care, reduced duplication, and enhanced transparency; and (5) structural implementation barriers including political discontinuity, weak enforcement mechanisms, and limited stakeholder engagement. Across stakeholder groups, feasibility was consistently linked to 3 actionable readiness conditions: clearly assigned responsibility and liability for shared data, enforceable technical requirements supported by certification or audit mechanisms rather than voluntary compliance, and financing models addressing both IT infrastructure and organizational change. Conclusions: Affinity domains are recognized as a viable interoperability model in the Czech Republic, but their implementation is constrained primarily by governance deficits rather than technical immaturity. Establishing an empowered coordinating authority, piloting enforceable domain structures, and aligning national governance with European Health Data Space requirements represent necessary steps toward operational interoperability. These findings provide empirically grounded insights into the governance conditions required for scalable health information exchange in post-transition health systems.