To evaluate the lifetime cost-utility of endoscopic microdiscectomy (EM) compared with open microdiscectomy (OM) for the surgical treatment of symptomatic lumbar disc herniation (LDH) from a Canadian healthcare payer perspective.

A three-state Markov state-transition model (responder, non-responder, death) with annual cycles simulated a hypothetical cohort of adults undergoing EM or OM over a lifetime horizon. Costs and quality-adjusted life years (QALYs) were discounted at 1.5% annually. Transition probabilities, utilities and costs were derived from randomized controlled trials, systematic reviews and published economic data. Cost-effectiveness was assessed using incremental cost-effectiveness ratios (ICERs) and net monetary benefit (NMB) at a willingness-to-pay threshold of $50,000 per QALY. Deterministic and probabilistic sensitivity analyses, including 1,000 Monte Carlo simulations, were performed to evaluate parameter uncertainty and model robustness.

In the base-case analysis, lifetime costs were $11,144 for OM and $11,162 for EM, with discounted QALYs of 24.55 and 24.59, respectively. EM yielded an incremental gain of 0.042 QALYs at an additional cost of $18, corresponding to an ICER of $434 per QALY. At a willingness-to-pay threshold of $50,000 per QALY, EM demonstrated a modestly higher NMB. Probabilistic sensitivity analysis showed substantial overlap between strategies, with EM favored in 55.2% of simulations.

EM and OM provide comparable lifetime health outcomes and economic value. Although EM showed a small base-case advantage, this difference was not robust to uncertainty. These findings should be interpreted in the context of local implementation factors, including endoscopic equipment costs and health system structure, which may influence real-world adoption.