OBJECTIVES: To determine the return on investment (ROI) for Australia’s health budget resulting from integration of structured exercise and diet counselling interventions into antenatal care as an adjunct to current standard practice.

METHODS: A decision-tree model was constructed to compare budget impact of implementing the lifestyle intervention versus usual care for pregnant Australian women in the years 2022 to 2026. The outcome of interest was ROI ratio for the lifestyle intervention program (cost of intervention divided by cost savings attributable to reduced maternal and infant adverse events) from the perspective of Australian healthcare funders. Adverse events included incidence of gestational diabetes, hypertensive disease in pregnancy, birth intervention, and admission to neonatal care unit, and were obtained from a published meta-analysis and population data. Costs were estimated from published data and clinical pathways and valued at the year in which they were incurred. Scenario analyses were conducted with an alternative data source for baseline risk and individual patient cost data to explore external validity of the base case results. Deterministic and probabilistic sensitivity analyses examined the impact of uncertainty in the model.

RESULTS: Implementation of the lifestyle intervention offers a ROI ratio of 4.75 over the 5-year program; hence every dollar spent on implementation resulted in a return of AUD4.75 in the model. The total 5-year intervention cost is projected to be AUD205 million, with cost offsets (from reduced incidence of maternal morbidity and adverse outcomes) of AUD1,022 million, and a health budget saving of AUD807 million (95% CI: AUD-129 million to AUD1,639 million). 93.3% of the iterations were cost saving, and results were robust to sensitivity and scenario analyses.