Study protocol for an economic evaluation and budget impact of implementation strategies to support routine provision of antenatal care for gestational weight gain: a stepped-wedge cluster trial

BACKGROUND: Antenatal clinical practice guidelines recommend routine assessment of weight and provision of advice on recommended weight gain during pregnancy and referral to additional services when appropriate. However, there are barriers to clinicians adopting such best-practice guidelines. Effective, cost-effective, and affordable implementation strategies are needed to ensure the intended benefits of guidelines are realised. This paper describes the protocol for evaluating the efficiency and affordability of implementation strategies compared to the usual practice in public antenatal services. METHOD: The prospective trial-based economic evaluation will identify, measure, and value key resource and outcome impacts arising from the implementation strategies compared with usual practice. The evaluation will comprise of (i) costing, (ii) cost-consequence analyses, where a scorecard approach will be used to show the costs and benefits given the multiple primary outcomes included in the trial, and (iii) cost-effectiveness analysis, where the primary outcome will be incremental cost per percent increase in participants reporting receipt of antenatal care for gestational weight gain consistent with the guideline recommendations. Affordability will be evaluated using (iv) budget impact assessment and will estimate the financial implications of adoption and diffusion of this implementation strategy from the perspective of relevant fund-holders. DISCUSSION: Together with the findings from the effectiveness trial, the outcomes of this economic evaluation will inform future healthcare policy, investment allocation, and research regarding the implementation of antenatal care to support healthy gestational weight gain. TRIAL REGISTRATION: Trial Registration: Australian and New Zealand Clinical Trials Registry, ACTRN12621000054819 (22/01/2021) http://www.anzctr.org.au/Trial/Registration/TrialReview.aspx?id=380680&isReview=true.