Cost-effectiveness of continuity of midwifery care for women with complex pregnancy: A structured review of the literature

Background: Critical evaluation of the cost-effectiveness and clinical effectiveness of continuity of midwifery care models for women experiencing complex pregnancy is an important consideration in the review and reform of maternity services. Most studies either focus on women who experience healthy pregnancy or mixed risk samples. These results may not be generalised across the childbearing continuum to women with risk factors. This review critically evaluates studies that measure the cost of care for women with complex pregnancies, with a focus on method and quality. Aims / objectives: To critically appraise and summarise the evidence relating to the combined cost-effectiveness, resource use and clinical effectiveness of midwifery continuity models for women who experience complex pregnancies and their babies in developed countries. Design: Structured review of the literature utilising a matrix method to critique the methods and quality of studies. Method: A search of Medline, CINAHL, MIDIRS, DARE, EMBASE, OVID, PubMed, ProQuest, Informit, Science Direct, Cochrane Library, NHS Economic Evaluation Database (NHSEED) for the years 1994 - 2018 was conducted. Results: Nine articles met the inclusion criteria. The review identified four areas of economic evaluation that related to women who experienced complex pregnancy and continuity of midwifery care. (1) cost and clinical effectiveness comparisons between continuity of midwifery care versus obstetric-led units; (2) cost of continuity of midwifery care and/or team midwifery compared to Standard Care; (3) cost-effectiveness of continuity of midwifery care for Australian Aboriginal women versus standard care; (4) patterns of antenatal care for women of high obstetric risk and comparative provider cost. Cost savings specific to women from high risk samples who received continuity of midwifery care compared with obstetric-led standard care was stated for only one study in the review. Kenny et al. 1994 identified cost savings of AUS $29 in the antenatal period for women who received the midwifery team model from a stratified sub-set of high-risk pregnant woman within a mixed risk sample of 446 women. One systematic review relevant to the UK context, Ryan et al. (2013), applied sensitivity analysis to include women of all risk categories. Where risk ratio for overall fetal/neonatal death was systematically varied based on the 95% confidence interval of 0.79 to 1.09 from pooled studies, the aggregate annual net monetary benefit for continuity of midwifery care ranged extremely widely from an estimated gain of £472 million to a loss of £202 million. Net health benefit ranged from an annual gain of 15 723 QALYs to a loss of 6 738 QALYs. All other studies in this review reported cost savings narratively or within mixed risk samples where risk stratification was not clearly stated or related to the midwifery team model only. Conclusions: Studies that measure the cost of continuity of midwifery care for women with complex pregnancy across the childbearing continuum are limited and apply inconsistent methods of economic evaluation. The cost and outcomes of implementing continuity of midwifery care for women with complex pregnancy is an important issue that requires further investigation. Robust cost-effectiveness evidence is essential to inform decision makers, to implement sustainable systems change in comparative maternity models for pregnant women at risk and to address health inequity.