Real-World Cost-Effectiveness of Three-Sessions Compared to Four-Sessions Intradermal Rabies Post-Exposure Prophylaxis in Patients Bitten by Dogs: A Decision Tree Model from the Patients’ Perspective

Abstract

Background: The annual incidence of rabies deaths has been estimated in Cambodia at nearly 5•8/100,000 person-years. The cost of post exposure prophylaxis (PEP) and travel is potentially a significant barrier for exposed patients and their families, although safety nets are in place to provide the prophylaxis at no cost for low-income families. Method: A decision-tree model compared the costs from the patients’ perspective and the disease outcomes of the Institut Pasteur du Cambodge (IPC) rabies PEP regimen versus the Thai Red Cross (TRC) rabies PEP regimen in patients exposed to WHO category II or III bites by dogs. Derived from the IPC database, data included the trajectory of 203,497 patients, 1,412 called-back patients and economic data on 201 patients. Uncertainty was addressed using one-way and probabilistic sensitivity analyses. Findings: Compared to the TRC regimen, the IPC regimen was cheaper and equally effective in patients with category II bites. In patients with category III bites, the IPC regimen was cheaper and its modeled effectiveness (probability of survival) was 0•04% (95% CI: 0 -0•12%) lower than the TRC regimen. Interpretation: Although the equivalence of the IPC regimen is backed by clinical and serological studies, its effectiveness may be lower than TRC’s for category III bites but not for category II bites. Funding: No funding supported this study. Declaration of Interest: None to declare. Ethical Approval: Ethical approval: all patients had approved the use of their personal data for research purposes and we accessed de-identified patient data. The Cambodian National Ethics Committee for Human Research approved the study (approval #046 dated 20 February 2015).