O-188 Tubal testing with Hysterosalpingo-foam sonography (HyFoSy) versus hysterosalpingography (HSG) during the fertility work-up: a cost-effectiveness analysis alongside a randomised controlled trial

Abstract Study question What are the costs and effects of management based on tubal patency testing by HyFoSy compared to HSG in infertile women during fertility work-up? Summary answer Management based on the results of either HyFoSy or HSG leads to similar pregnancy rates with lower costs for management based on HyFoSy. What is known already Traditionally, tubal patency testing during the fertility work-up is performed by HSG. We recently showed in a randomised controlled trial (RCT) that in infertile women scheduled for tubal patency testing, management based on the results of either HyFoSy or HSG leads to comparable diagnostic accuracy (FOAM trial, van Welie et al, 2022 conditionally accepted). Also, HyFoSy is associated with significantly less pain, it lacks ionizing radiation and exposure to iodinated contrast medium. Moreover, it can be performed by a gynaecologist during a one-stop fertility work-up. Here, we compare the costs and effects of both tubal patency strategies. Study design, size, duration We performed an economic evaluation alongside the FOAM trial, a multi-center cohort study with embedded RCT in the Netherlands. The FOAM trial included 1,160 infertile women (18-41 years) scheduled for tubal patency testing. Women underwent, in a randomised order, both HyFoSy and HSG. The results of both tests were compared and in case of discordant results for HyFoSy or HSG women were randomly allocated to management based on the results of either HyFoSy or HSG. Participants/materials, setting, methods The economic evaluation compared costs of management based on either test within 12 months in the entire study population and in women with discordant results. For the entire study population, we compared two strategies: one that follows the management based on HyFoSy and one based on HSG. We calculated incremental cost-effectiveness ratios (ICERs): the difference in total costs and in chance of live birth. Data were analyzed using the intention to treat principle. Main results and the role of chance Between May 2015 and January 2019, we studied 1,160 women, of which 1026 (88%) women underwent both tubal tests and had data available. They were divided in three groups: women with concordant (n = 747, 48% live births), inconclusive (n = 136, 40% live births) or discordant (n = 143, 41% had a live birth after management based on HyFoSy and 49% had a live birth after management based on HSG) results. When these data were integrated in the two strategies, one based on HyFoSy and one based on HSG, the estimated chance of live birth per management strategy was 47% after HSG and 46% after HyFoSy (difference 1.2% (95%CI: -1.5% to 3.4%)). For the procedures itself, HSG costed €266 and HyFoSy €132. When costs of additional fertility treatments were incorporated, the mean total costs per couple were €1,366 for the HSG strategy and €1,250 for the HyFoSy strategy (mean difference €152 (95%CI: €149 to €155). Taking into account the 1.2% increase in live birth rate after the HSG stratey, this leads to an ICER of €10,014 for one additional live birth after HSG compared to HyFoSy. Limitations, reasons for caution The number of inconclusive results for HyFoSy was higher than anticipated. This might be explained by the learning-curve of performing HyFoSy although training was mandatory. Women underwent both tests, therefore the immediate fertility enhancing effect e.g. by using oil-based contrast, could not be determined and is therefore not incorporated. Wider implications of the findings The diagnostic accuracy of HSG and HyFoSy are comparable, while HyFoSy leads to lower costs, is associated with less pain and no ionizing radiation without exposure to iodinated contrast. HyFoSy could replace HSG as first-line tubal patency test, although the direct fertility enhancing effect of both tests should be incorporated. Trial registration number NTR 4746