Abstract

Objectives

Genomic testing can shorten the diagnostic odyssey for people with rare diseases, yet clinical uptake has lagged funding policy in Australia. Therefore, we evaluated the 10-year budget impact of alternative implementation strategies for publicly funded genomic testing using national claims data and diffusion modeling.

Methods

Monthly Medicare Benefits Schedule claims (1993–2025) were analyzed for chromosomal microarray analysis (CMA), Fragile X (FMR1) testing, and genomic tests across 7 rare-disease groups (syndromic and non-syndromic intellectual disability, neuromuscular, inherited cardiac, renal ciliopathies/tubulopathies, congenital hearing loss, mitochondrial). Logistic, Gompertz, and Bass diffusion functions and Seasonal Autoregressive Integrated Moving-Average models were fitted to uptake and used to forecast 2025 to 2034 volumes. Scenarios included status quo, broadened second-line eligibility, and first-line exome sequencing/genome sequencing (ES/GS) replacing CMA/FMR1 (60:40 ES:GS). Costs used were the 1 July 2024 Medicare Benefits Schedule fees; the results are in Australian (AUD) dollars.

Results

Observed genomic testing volumes were below diffusion-implied trajectories. The 10-year cumulative spending was as follows: status quo AUD 1.1 million; broadened second-line AUD 7.5 million (incremental +6.4 million vs status quo); and first-line ES/GS AUD 6.2 million (incremental +5.1 million). In 2028, it was status quo AUD 0.23 million, second-line AUD 1.21 million, and first-line AUD 0.97 million. ES/GS achieved lower cumulative spend than the broadened second-line despite higher per-test fees, reflecting substitution from CMA/FMR1 and efficient diagnostic pathways.

Conclusions

Indication-by-indication funding has yielded slower-than-expected uptake and likely under-budgeting. A first-line genomic testing pathway, aligned with CMA criteria, could better match clinical need while constraining spend versus expanding second-line eligibility. Harmonized eligibility and streamlined implementation would improve access and planning.