Cost utility analysis of endoscopic biliary stent in unresectable hilar cholangiocarcinoma: decision analytic modeling approach

Abstract

The objective of this study was to evaluate the cost-utility of metal and plastic stent endoscopic biliary drainage in unresectable hilar cholangiocarcinoma (CCA) patients. Markov model was used to evaluate cost and quality-adjused life year (QALY) of endoscopic biliary drainage in unresectable hilar CCA. Costs of treatment were calculated from hospital charges at Srinagarind hospital in year 2008-2010 using health care provider perspective. Utilities of hilar CCA patients at Srinagarind hospital were used in this model. Transition probability of death in patients with endoscopic biliary drainage and effectiveness of biliary stent were retrieved from ongoing randomized controlled trial at Srinagarind hospital. Transition probability of death in patients with percutaneous transhepatic biliary drainage (PTBD) and effectiveness of PTBD were retrieved from literature review. Base case analyses and sensitivity analyses were performed and presented in terms of incremental cost per QALY gained. Under the baseline assumptions, metal stent is more effective but more expensive than plastic stent. An incremental cost per additional QALY gained is 192,584 baht. From probability sensitivity analysis presented in the form of cost-effectiveness acceptability curve, at the willing to pay threshold or decision threshold of 1 time GDP per capita (158,000 baht) and 3 times GDP per capita (474,000 baht) in year 2010, the probability of metal stent being cost-effective are 26% and 99.9% respectively. In conclusion, according to the model assumptions and the limitations of the study, endoscopic biliary drainage using metal stent is cost-effective compared to plastic stent at the willingness to pay threshold between one and three times GDP per capita in tertiary care hospital in Thailand in year 2010.