Universal school-based mental health promotion in Vietnam: a critical appraisal of a health-economic evaluation

A recent cost-utility analysis modeled the long-term cost-effectiveness of a universal, teacher-delivered school mental health program for adolescents in Vietnam. This key paper evaluation discusses how modeling choices - particularly the translation of short-term symptom outcomes into model-ready risk reductions, the handling of dichotomized thresholds, and assumptions about persistence of benefit - can materially influence long-term cost-effectiveness conclusions. We highlight the importance of distinguishing odds ratios from risk ratios for common outcomes, reporting population-average (marginal) risks and risk differences suitable for transition probabilities, and providing distributional information to assess whether apparent benefits are driven by movement around a cut-point. We also discuss how conclusions depend on structural assumptions about waning and the duration of effects, and on the clarity of the costing perspective and included cost components. We suggest reporting and scenario analyses that would improve transparency and strengthen the credibility of long-horizon results.