Treatment Costs

LNG-IUS cost ￥2273.8 RMB per woman on average compared with ￥6318.0 RMB for HNR. Mean treatment cost was substantially lower for LNG-IUS than for HNR. The mean cost difference favored LNG-IUS by ￥4044.2 RMB. Generalised linear models are used to analyse cost variation because they accommodate skewed distributions, heteroskedasticity, and non-linear predictor relationships. Treatment costs will be reported cumulatively and at specific time points, stratified by cancer stage using stage-specific means and medians. Follow-up costs beyond one year are estimated via normative costing based on standard treatment guidelines rather than observed real-world expenditure. Recall bias in retrospective cost collection is mitigated by capping the recall window at nine months and encouraging participants to reference medical bills and hospital records during interviews. Including indirect productivity costs alongside QALYs risks double-counting, as some health economics literature argues these costs are already captured within QALY measures.