Cost-effectiveness analysis of probiotics in patients with gestational diabetes mellitus: a model‑based pharmacoeconomic evaluation from the Chinese healthcare perspective

Gestational diabetes mellitus (GDM) is among the most common pregnancy complications, with its incidence increasing rapidly worldwide. Although lifestyle interventions and insulin therapy remain standard treatments, they can be difficult to maintain and costly. Because of the role of gut microbiota in GDM, probiotics have been proposed as a potential therapeutic option. This study aimed to evaluate the cost‑effectiveness of probiotics for GDM management in China. A cost‑effectiveness analysis was performed using a decision‑tree model in TreeAge Pro to compare probiotics with placebo following GDM diagnosis. The analysis was conducted from the Chinese healthcare system perspective with a short‑term time horizon corresponding to the 8‑week treatment period. This analysis should be interpreted as an acute‑treatment economic evaluation, not a comprehensive lifetime cost‑effectiveness analysis, as it does not capture long‑term maternal or offspring outcomes. No discounting was applied owing to the short time frame. The model incorporated GDM complications, preterm birth, and neonatal death as key health states. Probabilities, utilities, and costs were obtained from meta‑analyses and national pharmacoeconomic data. Health outcomes were measured in quality‑adjusted life years (QALYs), and the incremental cost‑effectiveness ratio (ICER) was calculated and compared with the willingness‑to‑pay (WTP) threshold of ¥257,094 per QALY. One‑way and probabilistic sensitivity analyses were conducted to test robustness. The probiotic strategy resulted in an average total cost of ¥2,119.29 and 0.14997 QALYs, while the placebo cost ¥1,687.90 and provided 0.14996 QALYs. The extremely high ICER of ¥65,400,488 per QALY arises primarily from the very small QALY difference (0.00001 QALYs, equivalent to approximately 5.3 quality‑adjusted life minutes) between strategies, reflecting the short treatment duration and limited health utility gains captured in the model. This ICER far exceeds the WTP threshold, demonstrating that probiotics are not cost‑effective compared with placebo. Sensitivity analyses confirmed the stability of these results. Under current Chinese healthcare economic conditions, probiotics do not represent a cost‑effective treatment for GDM. However, this conclusion is subject to uncertainty stemming from the limited utility gain captured and the short‑term modeling assumptions. Future research should evaluate long‑term effects, species‑specific outcomes, and regional utility values to refine policy decisions.