Cost Effectiveness Analysis of Elective Inductions in low-risk Nulliparous Women in Norway – A model-based study

Abstract

Background: Previous studies have indicated that elective induction of labor at 39 weeks of gestation for low-risk nulliparous women can be cost-effective. However, the health-related outcomes proved to be difficult to generalize across populations, and cost related outcomes depend on the healthcare system settings. Therefore, an update is necessary to assess the local context and draw valid conclusions. Objective: The objective of this study was to assess the cost-effectiveness of elective induction of labor for low-risk nulliparous women in Norway in comparison to expectant management from the health payer perspective. Additionally, this study aimed to determine the optimal time to induce labor: at 39 weeks or at 40 weeks. Methods: Two decision analytic models were developed in Microsoft Excel. One model compared elective induction of labor at 40 weeks of gestation for the hypothetical cohort of 15 000 low-risk nulliparous women versus expectant management until induction at week 41. The second model was informed by the best outcome decision in week 40 and compared induction of labor at 39 weeks of gestation versus continued expectant management. Observed effects were health outcomes as measured by QALY and cesarean sections avoided. The models relied on estimates of costs as provided by Norwegian Directorate of Health, and probabilities and health utilities obtained from the scientific literature. Results: The study showed that elective induction of labor at 39 weeks of gestation was a potentially cost-saving strategy compared to expectant management with ICER of 73 904 NOK per QALY gained and a total of 346 cesarean sections avoided. The results held true for 92% of the cases of 10 000 Monte Carlo simulations at willingness to pay threshold of 275 000 NOK. Elective induction of labor at 40 weeks of gestation was shown to be a potentially cost-saving strategy compared to expectant management with ICER of 69 218 NOK per QALY gained and a total of 852 cesarean sections avoided. The results held true for 87% of the cases. The overall conclusion was robust to changes in model parameters, with adverse neonatal outcome probabilities and cesarean section rates mostly affecting the magnitude of cost savings. Week 39 induction was the cost-effective strategy when compared to expectant management ending in elective induction at week 40. Conclusion: This study shows that elective induction is possibly cost-effective from the health payer perspective. However, an additional retrospective observational study is recommended together with the cost-effectiveness analysis from the hospital perspective to more accurately characterize the resulting health outcomes and capture the costs of this procedure.