Objective: We examined the cost-effectiveness of conservative management (CM) compared to planned caesarean hysterectomy (CH) for placenta accreta spectrum (PAS).

Design: A cost-effectiveness analysis in a theoretical cohort of patients.

Setting: A decision analytic model.

Population: A theoretical cohort of 1000 pregnant patients with PAS greater than 20 weeks gestation.

Methods: In base case analysis, we assumed that between 20% and 40% of individuals would be eligible for CM. Model inputs were derived from the literature. Analysis was conducted from a healthcare system perspective with a 1 year analytic horizon. Outcomes included hysterectomy, surgical site infection (SSI), length of hospitalisation, intensive care unit (ICU) admission and death. An incremental cost-effectiveness ratio (ICER) of $50 000 per quality-adjusted life year (QALY) defined cost-effectiveness. Sensitivity analyses were performed.

Main outcome measures: The cost gained per life year and per QALY.

Results: For base case estimates, CM was the cost-saving strategy with an ICER of $9330.51 USD. Compared to CH, CM resulted in 905 fewer hysterectomies, 80 fewer instances of SSI and five fewer deaths. CM resulted in 149 more admissions with length of stay > 5 days and 25 more ICU admissions. In probabilistic sensitivity analysis, CM was the cost-effective strategy in 71% of runs and the dominant strategy in 42% of runs.

Conclusions: CM was the cost-effective strategy for the management of PAS in greater than 70% of iterations of our model. Modelling demonstrated significant uncertainty in the comparative effectiveness of the two strategies, highlighting the need for prospective research evaluating the effectiveness of CM.