Cost-effectiveness of history-indicated cerclage vs cervical length assessment for prevention of preterm birth

BACKGROUND: Preterm birth is one of the major causes of neonatal morbidity and mortality. Preterm delivery is a large burden to our health care system, and a history of preterm birth is one of the most common risk factors for subsequent preterm birth. OBJECTIVE: We sought to examine the cost-effectiveness of the history-indicated cerclage strategy compared with the transvaginal ultrasound cervical length assessment strategy in individuals with a history of preterm birth.STUDY DESIGN: We developed a decision analysis model to compare history-indicated cerclage and cervical length assessment. The primary outcome was the net monetary benefit from a maternal and neonatal perspective of both strategies, defined as the value of an intervention with a known willingness to pay threshold for a unit of benefit. The time horizon was set to be a lifetime. Costs (in 2022 USD) included those for the cerclage, serial transvaginal ultrasounds, maternal care for admission, neonatal care, and severe disability. Probabilities, utilities, and costs were derived from the literature. A cost-effectiveness threshold was set at $100,000 per QALY (quality-adjusted life year). We first conducted 1-way sensitivity analyses with associated variables as sensitivity analyses. We then performed a probabilistic sensitivity analysis using Monte Carlo simulation with 1000 trials to test the robustness of the results in the setting of simultaneous changes in probabilities, costs, and utilities.RESULTS: In our base-case analysis, the history-indicated cerclage strategy compared to transvaginal ultrasound cervical length assessment was associated with more cost ($85,038 vs $70,155), with slightly less effectiveness from the maternal perspective (26.74 QALY vs 26.78 QALY) and from the neonatal perspective (28.91 QALY vs 29.06 QALY), and with less maternal and neonatal net monetary benefit. Therefore, the history-indicated cerclage strategy was dominated. With the 1000 trials of Monte Carlo simulation, transvaginal ultrasound cervical length assess-ment was the preferred strategy 84% and 88% of the time from the maternal and neonatal perspectives, respectively.CONCLUSION: The history-indicated cerclage strategy was more expensive and slightly less effective than the transvaginal ultrasound cervical length assessment strategy with a lower net monetary benefit.