Interpretation
Several economic evaluations of IOL have been undertaken, including
comparing IOL at 39 weeks (22-24) or 41 weeks (25) to expectant
management. An Australian study of outpatient (Foley) catheter with
inpatient IOL (26) found non-significantly higher mean costs ($6,524
OCF and $5,876 IPG). Although not directly comparable to our study as
they did not include a generic health outcome measure, they did
similarly report significantly fewer antenatal ward hours in
outpatient-balloon compared to inpatient-PG group. We observed a
slightly longer and more expensive stay in birth suite for women in
outpatient-balloon group, as was also reported in two Dutch CEA
alongside RCTs (27, 28). From a health economic perspective, it is
therefore tempting to consider outpatient-PG IOL, with a potential
reduction in cervical priming costs and time spent in antenatal ward,
especially for nulliparous women whose duration of induced labour can be
prolonged. However, our findings were of more adverse perinatal outcomes
amongst nulliparous women receiving PG (16). A 2014 systematic review,
meta-analysis and CEA on best method of IOL (29) found most
interventions compared had similar utility but differed on cost
outcomes. Titrated misoprostol solution and sublingual misoprostol had
the highest probability of being cost-effective. But given their
increased rates of uterine hyperstimulation, compared to mechanical
methods, misoprostol may also not be appropriate for outpatient cervical
priming. Future outpatient IOL studies should consider the role of
alternative mechanical methods, or different durations of insertion in
order to determine safe, cost-effective approaches that are acceptable
to women.
The decision-making around the choice of IOL method is complex and is
likely influenced by best-practice guidelines, clinician/health service
preferences, but also women’s’ beliefs, past experiences and willingness
to undergo a certain intervention. Although a clinician’s principal
focus may be to provide high-quality care, they share responsibility for
making the best decisions for a health system with finite resources, by
choosing cost-effective care options. In this study, outpatient-balloon
IOL resulted in both cost-saving and improved health outcomes with
reduced uncertainty for nulliparous women representing excellent value
for money. These findings should be considered for future
decision-making, along with evidence on safety and women’s preferences.