Cost, cost-consequence and cost-effectiveness evaluation of a practice change intervention to increase routine provision of antenatal care addressing maternal alcohol consumption

Zoe Szewczyk, Penny Reeves, Melanie Kingsland, Emma Doherty, Elizabeth Elliott, Luke Wolfenden, Tracey W. Tsang, Adrian Dunlop, Andrew Searles, John Wiggers

Implementation of antenatal clinical guideline recommendations for addressing maternal alcohol consumption is sub-optimal. There is a complete absence of evidence of the cost and cost-effectiveness of delivering practice change interventions addressing maternal alcohol consumption amongst women accessing maternity services. The study sought to determine the cost, cost-consequence and cost-effectiveness of developing and delivering a multi-strategy practice change intervention in three sectors of a health district in New South Wales, Australia. The trial-based economic analyses compared the costs and outcomes of the intervention to usual care over the 35-month period of the stepped-wedge trial. A health service provider perspective was selected to focus on the cost of delivering the practice change intervention, rather than the cost of delivering antenatal care itself. All costs are reported in Australian dollars ($AUD, 2019). Univariate and probabilistic sensitivity analyses assessed the effect of variation in intervention effect and costs. The total cost of delivering the practice change intervention across all three sectors was $367,646, of which $40,871 (11%) were development costs and $326,774 (89%) were delivery costs. Labour costs comprised 70% of the total intervention delivery cost. A single practice change strategy, 'educational meetings and educational materials' contributed 65% of the delivery cost. Based on the trial's primary efficacy outcome, the incremental cost effectiveness ratio was calculated to be $32,570 (95% CI: $32,566-$36,340) per percent increase in receipt of guideline recommended care. Based on the number of women attending the maternity services during the trial period, the average incremental cost per woman who received all guideline elements was $591 (Range: $329 - $940) . The average cost of the intervention per eligible clinician was $993 (Range: $640-$1928). The intervention was more effective than usual care, at an increased cost. Healthcare funders' willingness to pay for this incremental effect is unknown. However, the strategic investment in systems change is expected to improve the efficiency of the practice change intervention over time. Given the positive trial findings, further research and monitoring is required to assess the sustainability of intervention effectiveness and whether economies of scale, or reduced costs of intervention delivery can be achieved without impact on outcomes. The trial was prospectively registered with the Australian and New Zealand Clinical Trials Registry, No. ACTRN12617000882325 (date registered: 16/06/2017).