Health economic evaluation of discrete event simulation model for treating chronic obstructive pulmonary disease based on traditional chinese medicine syndrome differentiation

Abstract

Abstract Objectives To evaluate, from a Chinese healthcare system perspective, the cost-utility of three treatment strategies (Western medicine, Traditional Chinese Medicine [TCM], and combined therapy) for stable chronic obstructive pulmonary disease (COPD) using a discrete event simulation (DES) model parameterized with clinical trial data. Methods A DES model was developed for stable COPD patients (aged 18–80 years) from a Chinese healthcare system perspective. The model incorporated 24 baseline variables, six intermediate outcomes (FEV1, 6MWD, dyspnea, cough, sputum, COPD-PRO), and acute exacerbation as the final outcome. Multilevel mixed-effects models and Weibull regression updated these longitudinal outcomes every three months over a 2-year time horizon. Health outcomes were measured as quality-adjusted life years (QALYs), the primary outcome of the economic evaluation. Costs were estimated in 2013 RMB and adjusted to 2022 values using the China Consumer Price Index (CPI). Results In the three-month base-case analysis, patients with COPD showed a mean 6.8 m increase in six-minute walk distance (6MWD), 0.25 fewer acute exacerbations, and improved symptom scores. The mean two-year total cost was 12,726.18 RMB. Cost-utility ratios (CURs) were 5,066.79, 4,477.09, and 4,540.93 RMB/QALY for the Western medicine, TCM, and combined therapy groups, respectively. Compared with the TCM group, the combined therapy group incurred an additional 448 RMB and gained 0.060 additional QALYs, yielding an incremental cost-utility ratio (ICUR) of 7,467 RMB/QALY; Western medicine alone was dominated. At a willingness-to-pay (WTP) threshold of 85,698 RMB/QALY (1x China’s per-capita GDP), the probability that combined therapy was cost-effective was 98.5% in probabilistic sensitivity analysis (400 iterations). Conclusions The DES model was useful for the health-economic evaluation of TCM in COPD. The 0.060 QALY gain associated with combined therapy corresponds to approximately 22 days in full health and falls within the reported minimum clinically important difference (MCID) range for COPD (0.03–0.07 QALY), suggesting that the benefit may be clinically perceptible at the group level; individual-level variation nonetheless warrants caution. These exploratory findings, which carry potential overfitting risk given the single-trial design, require validation in larger, geographically diverse multi-center studies.