To Örebro University

OBJECTIVE: To assess the cost-effectiveness of induction of labour (IOL) at 41 weeks of gestation compared with expectant management until 42 weeks of gestation.

DESIGN: A cost-effectiveness analysis alongside the Swedish Postterm Induction Study (SWEPIS), a multicentre, randomised controlled superiority trial.

SETTING: Fourteen Swedish hospitals during 2016-2018.

POPULATION: Women with an uncomplicated singleton pregnancy with a fetus in cephalic position were randomised at 41 gestational weeks to IOL or to expectant management and induction at 42 gestational weeks.

METHODS: Health benefits were measured in life years and quality adjusted life years (QALYs) for mother and child. Total cost per birth was calculated, including healthcare costs from randomisation to discharge after the delivery, for mother and child. Incremental cost-effectiveness ratios (ICERs) were calculated by dividing the difference in mean cost between the trial arms by the difference in life years and QALYs, respectively. Sampling uncertainty was evaluated using non-parametric bootstrapping.

MAIN OUTCOME MEASURES: The cost per gained life year and per gained QALY.

RESULTS: The differences in life years and QALYs gained were driven by the difference in perinatal mortality alone. The absolute risk reduction in mortality was 0.004 (from 6/1 373 to 0/1 373). Based on Swedish life tables, this gives a mean gain in discounted life years and QALYs by 0.14 and 0.12 per birth, respectively. The mean cost per birth was €4,108 in the IOL group (n=1 373) and €4,037 in the expectant management group (n=1 373), mean difference €71 (95% CI -€232 to €379). The ICER for IOL compared with expectant management was €545 per life year gained and €623 per QALY gained. Confidence intervals were relatively wide and included the possibility that IOL had both lower costs and better health outcomes.

CONCLUSIONS: IOL at 41 gestational weeks results in a better health outcome and no significant difference in costs. IOL is cost-effective compared to expectant management until 42 gestational weeks using standard threshold values for acceptable cost per life year/QALY.