Cost-effectiveness analysis
VTE, venous thromboembolism
We followed a detailed health economics analysis plan developed before the end of the trial and last modified before the freezing of the trial database. We chose a cost-effectiveness analysis instead of a cost minimization procedure, with a non-inferiority margin of 1.35%, as described in the published study protocol [The primary medical outcome was the percentage of patients without undetected VTE averted (defined as venous thromboembolism (VTE) diagnosis at 3 months after exclusion of PE during the initial ED visit). The economic endpoint was the incremental cost-effectiveness ratio (ICER), expressed as the difference in costs divided by the difference in patients without cost per undetected VTE averted (i.e. patients correctly diagnosed), between the intervention and control strategies. Total costs were estimated from inclusion (the visit to ED) and over a three-month follow-up period. Given the non-inferiority hypothesis, the ICER was initially planned to estimate the small health loss (acceptable increase in diagnostic failure) for a reduction in cost.Due to the short duration of this study, costs and outcomes were not discounted. We adopted a healthcare system perspective with cost expressed in Euros (€), in 2022 prices [