Objective: The current treatment options available for patients with unresectable hilar cholangiocarcinoma [CCA] are endoscopic biliary drainage [EBD] using a metal stent, percutaneous transhepaticbiliary drainage [PTBD], and palliative care. However, information regarding their cost-effectiveness is not available.This study aimed to compare the cost utility between palliative biliary drainage [EBD or PTBD] and palliative care.

Materials and Methods: We used 2 methods for evaluation, direct calculation and the Markov decision analysis model. The cost of treatment and quality-adjusted life years [QALY] in the EBD, PTBD and palliative care groups were collected from the cohorts of unresectable hilar CCA database at a tertiary care hospital in Thailand. Transition probabilities were derived from international literature and the cohorts. Base-case and sensitivity analysis was also performed.

Results: Compared with palliative care, the incremental cost per additional QALY gained from EBD and PTBD using the direct calculation method were 422,822 baht (US$ 12,622) and 490,578 baht (US$ 14,644) per QALY gained, respectively. This result was in concordance with the Markov model. The ICER from EBD and PTBD were 655,520 baht (US$19,568) and 6,548,398 baht (US$195,475) per QALY gained, respectively. According to probabilistic sensitivity analysis using the Markov model, EBD is preferable to palliative care if the willingness to pay [WTP] is higher than 650,000 baht (US$19,403) per QALY gained. PTBD is not cost-effective compared to palliative care at any WTP threshold. At a WTP threshold of 160,000 Thai baht (the threshold of Thailand; US$ 4,776 per QALY gained) neither EBD nor PTBD were found to be cost-effective. At this threshold, only palliative care is cost-effective.

Conclusion: EBD is more cost-effective than PTBD when compared with palliative care in cases of unresectable hilar CCA, but at the WTP threshold of Thailand only palliative care is cost-effective.

Keywords: Cost-effectiveness, Cost utility, Endoscopic biliary drainage, Hilar cholangiocarcinoma, Percutaneoustranshepatic biliary drainage, Palliative