Genomic Testing in Australia: A Budget Impact Analysis Using Diffusion Modeling From a Healthcare System Perspective

Area of Science:

• Genomics
• Health Economics
• Rare Diseases

Background:

• Genomic testing accelerates rare disease diagnosis but faces slow clinical adoption in Australia.
• Current funding policies and implementation strategies may not align with clinical needs.

Purpose of the Study:

• To evaluate the 10-year budget impact of different genomic testing implementation strategies in Australia.
• To compare the cost-effectiveness of status quo, broadened second-line, and first-line exome/genome sequencing (ES/GS) approaches.

Main Methods:

• Analysis of Australian Medicare Benefits Schedule claims data (1993-2025) for genomic tests across seven rare disease groups.
• Utilized diffusion modeling (Logistic, Gompertz, Bass functions) and time-series analysis (SARIMA) to forecast testing volumes.
• Scenarios included status quo, expanded second-line testing, and first-line ES/GS replacing chromosomal microarray analysis (CMA) and Fragile X (FMR1) testing.

Main Results:

• Observed genomic testing volumes lagged behind projected trajectories.
• The 10-year cumulative spending projections were: status quo AUD 1.1M, broadened second-line AUD 7.5M, and first-line ES/GS AUD 6.2M.
• First-line ES/GS demonstrated lower cumulative costs than broadened second-line testing, despite higher per-test prices, due to efficient diagnostic pathways.

Conclusions:

• Current indication-by-indication funding has led to slower-than-expected uptake and potential under-budgeting.
• A first-line genomic testing pathway, aligned with CMA criteria, could better meet clinical needs and manage costs.
• Harmonized eligibility criteria and streamlined implementation are crucial for improving patient access and healthcare planning.