Cost-effectiveness of ovarian stimulation agents for IUI in couples with unexplained subfertility

STUDY QUESTION: Which agent for ovarian stimulation (OS) is the most cost-effective option in terms of net benefit for couples with unexplained subfertility undergoing IUI? SUMMARY ANSWER: In settings where a live birth is valued at €3000 or less, between €3000 and €55 000 and above €55 000, clomiphene citrate (CC), Letrozole and gonadotrophins were the most cost-effective option in terms of net benefit, respectively. WHAT IS KNOWN ALREADY: IUI-OS is a common first-line treatment for couples with unexplained subfertility and its increased uptake over the past decades and related personal or reimbursed costs are pressing concerns to patients and health service providers. However, there is no consensus on a protocol for conducting IUI-OS, with differences between countries, clinics and settings in the number of cycles, success rates, the agent for OS and the maximum number of dominant follicles in order to minimise the risk of a multiple pregnancy. In view of this uncertainty and the association with costs, guidance is needed on the cost-effectiveness of OS agents for IUI-OS. STUDY DESIGN, SIZE, DURATION: We developed a decision-analytic model based on a decision tree that follows couples with unexplained subfertility from the start of IUI-OS to a protocoled maximum of six cycles, assuming couples receive four cycles on average within one year. We chose the societal perspective, which coincides with other perspectives such as that from health care providers, as the treatments are identical except for the stimulation agent. We based our model on parameters from a network meta-analysis of randomised controlled trials for IUI-OS. We compared the following three agents: CC (oral medication), Letrozole (oral medication) and gonadotrophins (subcutaneous injection). PARTICIPANTS/MATERIALS, SETTING, METHODS: The main health outcomes were cumulative live birth and multiple pregnancy. As the procedures are identical except for the agent used, we only considered direct medical costs of the agent during four cycles. The main cost-effectiveness measures were the differences in costs divided by the differences in cumulative live birth (incremental cost-effectiveness ratio, ICER) and the probability of the highest net monetary benefit in which costs for an agent were deducted from the live births gained. The live birth rate for IUI using CC was taken from trials adhering to strict cancellation criteria included in a network meta-analysis and extrapolated to four cycles. We took the relative risks for the live birth rate after Letrozole and gonadotrophins versus CC from that same network meta-analysis to estimate the remaining absolute live birth rates. The uncertainty around live birth rates, relative effectiveness and costs was assessed by probabilistic sensitivity analysis in which we drew values from distributions and repeated this procedure 20 000 times. In addition, we changed model assumptions to assess their influence on our results. MAIN RESULTS AND THE ROLE OF CHANCE: The agent with the lowest cumulative live birth rate over 4 IUI-OS cycles conducted within one year was CC (29.4%), followed by Letrozole (32.0%) and gonadotrophins (34.5%). The average costs per four cycles were €362, €434 and €1809, respectively. The ICER of Letrozole versus CC was €2809 per additional live birth, whereas the ICER of gonadotrophins versus Letrozole was €53 831 per additional live birth. When we assume a live birth is valued at €3000 or less, CC had the highest probability of maximally 65% to achieve the highest net benefit. Between €3000 and €55 000, Letrozole had the highest probability of maximally 62% to achieve the highest net benefit. Assuming a monetary value of €55 000 or more, gonadotrophins had the highest probability of maximally 56% to achieve the highest net benefit. LIMITATIONS, REASONS FOR CAUTION: Our model focused on population level and was thus based on average costs for the average number of four cycles conducted. We also based the model on a number of key assumptions. We changed model assumptions to assess the influence of these assumptions on our results. WIDER IMPLICATIONS OF THE FINDINGS: The high uncertainty surrounding our results indicate that more research is necessary on the relative effectiveness of using CC, Letrozole or gonadotrophins for IUI-OS in terms of the cumulative live birth rate. We suggest that in the meantime, CC or Letrozole are the preferred choice of agent. STUDY FUNDING/COMPETING INTEREST(S): This work was supported by ZonMw Doelmatigheidsonderzoek, grant 80-85200-98-91072. The funder had no role in the design, conduct or reporting of this work. BWM is supported by a NHMRC Practitioner Fellowship (GNT1082548). B.W.M. reports consultancy for ObsEva, Merck KGaA and Guerbet and travel and research support from ObsEva, Merck and Guerbet. All other authors have no conflicts of interest to declare. TRIAL REGISTRATION NUMBER: N/A.