Strengths and limitations
This research has generated detailed data on utility weights and costs
relating to IOL that can be used in other economic evaluations. It adds
to the scarce literature in this context. Conducting a cost-utility
analysis (CUA) with generic health outcome measure (QALY) rather than
other types of cost-effectiveness analyses (CEA) with outcomes measured
in clinical terms (e.g. reduction in stillbirths), enables comparison to
other cost-effectiveness outcomes across different fields, and aids
decision-makers in selecting healthcare interventions with best value
for money. In addition, we used real-life data from a large multi-centre
RCT including actual costs and clinical events observed. The results of
this trial have been reported in three phases, including clinical
outcomes (16), women’s preferences (15) and now cost-effectiveness
outcomes. Our findings from different angles strengthen the confidence
in our conclusions with the economic benefit, safety and preference of
nulliparous women for outpatient-balloon IOL.
Although this was the largest RCT of outpatient IOL undertaken, more
research with larger patient cohorts and in different settings is
warranted to confirm our conclusions and explore generalisability of
results. The costing approach also had some limitations due to the
nature of administrative records as hourly costs per length of stay in
each clinical unit were calculated based on patient cohort averages
(bottom-down approach) rather than a sum of each individual cost
component per patient (bottom-up approach), which is regarded as the
gold standard in costing. We are nonetheless confident that our costing
methodology did not significantly influence overall costs since all
relevant components were detailed, including midwifery, nursing, medical
and allied health staff costs, pathology, radiology, equipment,
consumables, hotel services and business overheads. Furthermore, the
time horizon in this evaluation only included immediate adverse events
until discharge from hospital for both mother and baby. It is possible
that some women may have experienced long-term physical or psychological
impact associated with their birth experience, but this was beyond the
scope of this study. Finally, all model-based analyses have inherent
limitations and might not capture all real-world events.