A Theory-Informed Approach to Delivering Genomic Testing for Paediatric Inborn Errors of Immunity

Introduction Genomic testing is essential to diagnosing and treating paediatric inborn errors of immunity (IEIs). A model-of-care (MoC) was established at the Queensland Children’s Hospital to support the delivery of IEI genomic testing. While the MoC has demonstrated feasibility and acceptability among clinicians and families, challenges remain in integrating testing into routine practice. Aim Assess key challenges to implementing paediatric IEI genomic testing into routine care via i) process mapping with healthcare providers and ii) auditing state-wide genomic testing practices. Method Process-mapping semi-structured interviews were conducted with healthcare providers (n = 16) involved in facilitating paediatric IEI genomic testing (i.e., immunologists, nurses, laboratory staff, and genetic counsellors). Interviews were audio-recorded, transcribed, analysed via content analysis, and mapped to the Consolidated Framework for Implementation Research (CFIR). All instances of paediatric IEI genomic testing since 2017 were audited to capture state-wide testing practices (e.g., test modality, diagnostic rate, test documentation) and mapped to CFIR. Results Significant variation in genomic testing practices was identified among providers. Improvement areas were primarily related to the outer setting and individual characteristics of CFIR, including the need to reorganise the immunogenetics team meetings, strengthen communication between clinical and laboratory staff, and implement effective processes for tracking genomic testing. Audit data revealed 441 instances of IEI genomic testing among 291 patients. While the MoC significantly improved patient identification for genomic testing, test documentation (e.g., consent, results), and result interpretation, areas for improvement were noted that related to all aspects of CFIR (e.g., development of family-friendly resources, improved genomics education for providers). Conclusions The MoC improved paediatric IEI genomic testing practices. The application of implementation science methodology provides a robust approach to identifying opportunities to enhance service delivery. Findings will guide the development of targeted strategies to address identified areas for improvement and co-design resources for providers and families.