In a retrospective observational econometric analysis Luo et al. from the Panzhihua Central Hospital, Sichuan Provincial People’s Hospital, Chengdu, Sichuan, China 1) in Frontiers in Public Health attempt to quantify the cost-containment effects of DRG-based payment systems in China hospitals using advanced statistical tools. They claim significant cost reductions (especially in drug and material expenditures) and more “concentrated” cost distribution post-reform.
Major Criticisms
1. **Shallow Econometric Sophistication Masquerading as Rigor**
While Propensity Score Matching (PSM) and Difference-in-Differences (DiD) models are commonly used to infer causal effects, their validity hinges on critical assumptions — none of which are addressed with sufficient care here. The authors provide no robustness checks, falsification tests, or sensitivity analyses. The technical glitter hides conceptual rust.