Economic Evaluation of Midazolam–Droperidol Combination, Versus Droperidol or Olanzapine for the Management of Acute Agitation in the Emergency Department: A Within-Trial Analysis

Background The combination of midazolam and droperidol has proven superior to droperidol or olanzapine monotherapy in the management of acute agitation in emergency departments (EDs). Objective This is the first economic analysis to evaluate the cost–benefit and cost effectiveness of the midazolam–droperidol combination compared with droperidol or olanzapine for the management of acute agitation in EDs. Methods This analysis used data derived from a randomised, controlled, double-blind clinical trial conducted in two metropolitan Australian EDs between October 2014 and August 2015. The economic evaluation was from the perspective of Australian public hospital EDs. The main outcomes included agitation management time and the agitation-free time gained. Sensitivity analyses were undertaken. Results The midazolam–droperidol combination was the least costly regimen (Australian dollars [AU$]46.25 per patient) compared with the droperidol and olanzapine groups (AU$92.18 and AU$110.45 per patient, respectively). The main cost driver for all groups was the cost of the labour required during the initial adequate sedation. The combination afforded an additional 10–13 min of mean agitation-free time gained, which can be translated to additional savings of AU$31.24–42.60 per patient compared with the droperidol and olanzapine groups. The benefit–cost ratio for the midazolam–droperidol combination was 12.2:1.0, or AU$122,000 in total benefit for every AU$10,000 spent on management of acute agitation. Sensitivity analyses over key variables indicated these results were robust. Conclusions The midazolam–droperidol combination may be a cost-saving and dominant cost-effective regimen for the treatment of acute agitation in EDs as it is more effective and less costly than either droperidol or olanzapine monotherapy.