Importance: Structured antenatal diet and physical activity interventions have been shown to be associated with reduced adverse pregnancy outcomes and recommended to be routinely offered to all pregnant women. The health cost implications of population-level implementation are unclear.
Objective: To estimate the budget impact associated with integrating structured diet and physical activity interventions into routine antenatal care.
Design, setting, and participants: This economic evaluation was conducted from the perspective of Australian health funders. An open-source decision-tree model was constructed to compare the projected budget outcomes of implementing lifestyle intervention vs usual care. Scenario, deterministic, and probabilistic sensitivity analysis were completed. The study setting was Australian health services, and the study population was all Australian women projected to give birth in the years 2022 to 2026 (approximately 330 000 per year).
Interventions: Structured diet and physical activity intervention provided by trained health professionals, integrated into routine antenatal care. Comparator was usual care, which currently in Australia does not include routine structured lifestyle interventions.
Main outcomes and measures: Return on investment (ROI) ratio for lifestyle intervention (cost of intervention divided by cost savings attributable to reduced maternal and infant adverse events) from the perspective of Australian health care funders. Adverse events were obtained from a published meta-analysis and population data. Costs were estimated from aggregate trial data and clinical pathways and valued at the year incurred.
Results: Intervention offered an ROI ratio of 4.75 over the 5-year program; hence every Australian dollar spent on implementation produced an estimated return of A$4.75. The projected total 5-year intervention cost was A$205 million ($151 million), with cost offsets (from reduced incidence of adverse pregnancy outcomes) of A$1022 million ($755 million), and health budget savings of A$807 million (95% CI, A$129 million to A$1639 million) ($596 million [95% CI, $95 million to $1211 million]); 93.3% of the 10 000 iterations were within cost saving, and results were robust to scenario and sensitivity analyses.
Conclusions and relevance: This economic evaluation found that providing access to structured diet and physical activity lifestyle interventions for all pregnant Australian women was estimated to provide strong return on investment for health funders. The open-source model developed can be used by other jurisdictions and health services to explore cost implications of implementation within their patient population.