Universal cervical length screening with a cervicometer to prevent preterm birth <34 weeks: a decision and economic analysis.

Preterm birth is a leading cause of neonatal morbidity and mortality worldwide; evidence-based strategies to decrease preterm birth are desperately needed. The purpose of this study was to estimate which of three strategies for screening for shortened cervix in asymptomatic low-risk women is the most cost-effective in terms of prevention of preterm birth and associated morbidity. A decision analysis model was developed from available published evidence comparing three strategies in screening asymptomatic low-risk women for shortened cervix: (1) cervicometer with subsequent referral for transvaginal ultrasound, (2) transvaginal ultrasound screening, and (3) no screening. The cost and effectiveness of each strategy was assessed in terms of quality-adjusted life-years (QALYs), and cost in US dollars. Screening with a cervicometer with referral was the most cost-effective strategy and represented a savings of $999.65 ($11,617.28 versus $12,616.93) over screening with ultrasound, and a savings of $15,601.62 ($11,617.28 versus $27,218.90) over no screening. Costs for outcomes ranged from $3528 for a healthy neonate ≥34 weeks to $717,467.5 for a neonate <34 weeks with severe morbidity. The cervicometer strategy avoided 11.68 neonatal deaths per 1000 deliveries (3.59 deaths versus 15.27 deaths) compared with no screening, and avoided 0.73 neonatal deaths per 1000 deliveries (3.59 deaths versus 4.32 deaths) compared with ultrasound strategy. The cervicometer strategy prevented 82.44 preterm births per 1000 deliveries (22.56 versus 105.00) compared with no screening, and 5.10 preterm births per 1000 deliveries (22.56 versus 27.66) compared with ultrasound strategy. Per QALY, cervicometer screening cost $386.57, transvaginal ultrasound cost $420.31, and no screening cost $922.73. Sensitivity analyses confirmed the robustness of these findings, including evaluation across the range of quoted transvaginal ultrasound costs ($43-$300). A simulation of universal screening of asymptomatic low-risk women with a cervicometer with subsequent referral for ultrasound for those with a cervix <25 mm is cost-effective and yields the greatest reduction in preterm births at <34 weeks. A risk simulation trial noted that a cervicometer strategy may be more expensive than a universal transvaginal ultrasound strategy, but both are less expensive than a no screening strategy.