Cost-effectiveness of transvaginal ultrasound cervical length screening in singletons without a prior preterm birth: an update

Abstract

We sought to reevaluate the cost-effectiveness of universal transvaginal ultrasound (TVU) cervical length (CL) screening in singleton pregnancies without prior spontaneous preterm birth. We developed a decision model to assess costs and effects of universal TVU CL screening at 18-23 weeks' gestation compared to routine care for singleton pregnancies without prior preterm birth. Based on recent data, the model contains the following updates: (1) reduced incidence of CL ≤20 mm at initial screening ultrasound (0.83%), (2) vaginal progesterone supplementation for women with CL ≤20 mm, (3) additional ultrasound(s) for women with CL 21-24.9 mm, and (4) the assumption that vaginal progesterone reduces the rate of preterm birth <34 weeks' gestation by 39% if a short CL is diagnosed. The primary outcome was incremental cost-effectiveness ratio. We assumed a willingness to pay of $100,000 per quality-adjusted life year (QALY) gained. Additional outcomes included incidence of offspring with long-term neurological deficits and neonatal death. Sensitivity analyses were performed to assess the robustness of the results. For every 100,000 women screened, universal TVU CL screening costs $9132 compared to routine care. Screening results in 215 QALYs gained and 10 fewer neonatal deaths or neonates with long-term neurologic deficits per 100,000 women screened. Based on the updated data, universal CL screening in low-risk women remains a cost-effective strategy (incremental cost-effectiveness ratio = $43/QALY), but is not cost saving as previously estimated. Sensitivity analyses reveal that when incidence of TVU CL ≤20 mm is <0.31%, universal TVU CL screening is no longer cost-effective. Additionally, when TVU CL costs >$314, progesterone reduces preterm delivery risk before 34 weeks <19%, or the incidence of a TVU CL 21-24.9 mm is >6.5%, CL screening is also no longer cost-effective. Despite the reduced incidence and efficacy used in this model, universal TVU CL continues to be cost-effective when compared to routine care in singletons without prior preterm birth.