Genomic test stewardship at scale: retrospective evaluation of a statewide public health service

Technical Summary: Genomic Test Stewardship at Scale

Problem Statement
The integration of genomic testing (GT) into routine mainstream healthcare ("mainstreaming") faces significant barriers, including a complex testing landscape, a shortage of clinical genetics expertise, and the difficulty of scaling support models like embedded genetic counsellors. Non-genetic clinicians often lack the necessary upskilling to order and interpret GT appropriately, leading to issues such as insufficient clinical information, inappropriate test selection, and inadequate patient consent. While genetic laboratory stewardship programs exist to guide clinicians, most evaluations are limited to North American institutional or commercial settings. There is a lack of evidence regarding the implementation and sustainability of stewardship models within large, integrated public health systems.

Methodology
This retrospective observational study evaluated the implementation of the Genetic Testing Stewardship (GeTS) service, a genetic counsellor-led model embedded within Pathology Queensland (PQ), the centralised public pathology provider for the state of Queensland, Australia. The service operates with a 2.6 full-time equivalent (FTE) team comprising senior genetic counsellors and a senior laboratory scientist, supported by on-call clinical geneticists and pathologists.

• Scope: The study analyzed operational data from February 2023 to June 2025, covering 5,331 genomic test orders eligible for review (sendaway tests and flagged internal tests) out of 21,376 total sendaway requests.
• Workflow: Eligible tests undergo a review for clinical information adequacy, test appropriateness, and consent. If issues are identified, GeTS staff contact the ordering clinician (via phone or email) to provide targeted guidance. Tests are cancelled only if there is no response after four weeks or if the request is deemed inappropriate.
• Evaluation Framework: The study utilized the Proctor Implementation Framework, focusing on late-stage outcomes: fidelity (performance of stewardship functions), penetration (reach across health districts and specialties), sustainability (workload management and integration), and implementation cost.
• Data Analysis: Descriptive statistics were used to analyze review reasons, modification rates, clinician engagement, and cost differences between initial and final test orders. Cost analysis followed cost minimisation principles.

Key Contributions and Results

• Fidelity and Intervention Rates: Of the 5,331 reviewed tests, 54% (n=2,878) required follow-up. The primary reasons for follow-up were insufficient clinical information (36.3%), inappropriate test selection (34.1%), and inadequate consent (23.6%).

  • Modifications: 11.2% of follow-up cases resulted in test modification, most commonly selecting a more appropriate test (38.8%).
  • Withdrawals: 24.1% of reviewed tests were withdrawn, primarily due to inappropriate requests (e.g., predictive testing outside scope, testing minors inappropriately).
  • Resolution: 91.0% of reviews were resolved independently by the GeTS team (counsellors or scientists) without escalating to genetic pathologists or clinical geneticists. This independence rate increased from 86.0% to 98.0% over the study period.

• Penetration and Reach: The service achieved broad penetration across 15 of 16 Queensland Health and Hospital Services (HHS), covering major metropolitan, regional, and remote areas. Requests originated from 22 specialties, with the highest volume from Paediatrics (24%) and Neurology (19.5%).

• Clinician Engagement and Education: The service provided direct educational guidance to 1,184 clinicians (2,228 instances of education). Key educational topics included obtaining/documented consent (18.0%), clinical documentation (13.1%), and appropriate test selection (8.8%). Additionally, the team delivered 42 integration activities, including workshops and laboratory process improvements.

• Implementation Cost: Test modifications resulted in total cost savings of AUD$558,500.48 (€362,810.55). In 80.8% of altered tests, costs decreased, primarily due to test cancellations (71.5%).

Significance and Claims
The paper claims that the GeTS service demonstrates the efficacy and sustainability of embedding a genetic counsellor-led stewardship model within a statewide public health system. The study highlights several key findings:

1. Scalability: The model successfully managed high volumes of test requests across a vast, diverse geographic area, overcoming the limitations of traditional embedded counsellor models which are difficult to scale due to workforce constraints.
2. Educational Impact: The service functioned not merely as a gatekeeper but as an educational resource, improving clinician capability in consent, documentation, and test selection through real-time, peer-based support.
3. Workforce Efficiency: By resolving 91% of reviews independently, the model reduced the workload on specialist geneticists and pathologists, allowing them to focus on complex analytical roles.
4. Economic Viability: The service generated significant cost savings through the prevention of inappropriate testing, suggesting economic sustainability alongside clinical benefits.

The authors conclude that this model addresses critical gaps in mainstreaming genomic testing by providing a structured, scalable approach that supports non-genetic clinicians while preserving specialist resources for complex cases. They note that while the study demonstrates successful implementation, further prospective evaluations incorporating patient-level outcomes (e.g., diagnostic yield) are needed to fully assess long-term scalability and impact.