Main findings
Outpatient-balloon IOL is cost-saving with lower costs and better health
outcomes than inpatient-PG IOL. The robustness of these findings was
tested through sensitivity analyses varying the costs of CS, and the
mean hourly costs in antenatal ward, birth suite, postnatal ward, and
neonatal nurseries. In all tested scenarios, outpatient-balloon IOL was
favoured, with consistently higher NMB and an ICER below the WTP
threshold. Although outpatient-balloon IOL had a higher mean NMB and
lower cost/QALY gained these results are not conclusive that
outpatient-balloon IOL is the preferred alternative for all women.
Indeed, the probabilistic sensitivity analyses showed outpatient-balloon
IOL was cost-effective 55.3% of the time. The subgroup analyses by
parity, however, more strongly indicated cost-effectiveness of
outpatient-balloon IOL for nulliparous women (NMB $28,420 vs $25,675)
and inpatient-PG IOL for parous women (NMB $36,969 vs $34,210).
Subgroup analysis by cervix favourability was surrounded by higher
levels of uncertainty.
The difference in cost outcomes between the two methods of IOL was
largely due to the amount of time spent in the antenatal ward.
Outpatient-balloon IOL was associated with a saving of almost 13 hours
in antenatal ward care and, consequently, the mean costs were more than
six times higher in the inpatient-PG group ($781 vs $129).
Furthermore, cervical priming costs in the balloon group were less than
half that of the PG group ($49 vs $105). The mean length of stays in
birth suite and in the postnatal ward were slightly longer in the
balloon group (~1.5hrs) which may reflect the higher
proportion of nulliparous women in this group (72.7% vs 67.1%), who
typically experience a longer labour and longer postnatal stay than
parous women. Whilst acknowledging the inherent difficulties in costing
each hour of care in each clinical unit, these findings highlight the
importance of considering location and not just the duration of care
when designing cost-effective models of care. Our findings from a health
services perspective suggest that using outpatient-balloon IOL is
expected to be cost-saving, especially for nulliparous women. In
practical terms cervical priming costs will be reduced and less time
spent in antenatal wards is expected to reduce costs as well as free up
both hospital beds and staff time. The actual impact within health
services might differ between facilities and should be further explored
in future studies.