Impact of country-specific EQ-5D-3L tariffs on the economic value of systemic therapies used in the treatment of metastatic pancreatic cancer

Background Previous Canadian cost-effectiveness analyses in cancer based on the EQ-5D-3L (EuroQoL, Rotterdam, Netherlands) have commonly used U.K. or U.S. tariffs because the Canadian equivalent only just recently became available. The implications of using non-Canadian tariffs to inform decision-making are unclear. We aimed to re-evaluate an earlier cost-effectiveness analysis of therapies for metastatic pancreatic cancer (originally performed using U.S. tariffs) with tariffs from Canada and various other countries to determine the impact of using non-country-specific tariffs. Methods We used tariffs from Canada, the United States, the United Kingdom, Denmark, France, Germany, Japan, the Netherlands, and Spain to derive EQ-5D-3L utilities for the 10 health states in the pancreatic cancer model. Quality-adjusted life years (QALYS) and incremental cost-effectiveness ratios (ICERS) were generated, and probabilistic sensitivity analyses (PSAS) were performed. Results Canadian utilities are generally lower than the corresponding U.S. utilities and higher than those for the United Kingdom. Compared with the Canadian-valued scenarios, U.S. and U.K. estimates were statistically different for 3 and 9 scenarios respectively. Overall, 35% of the non-Canadian utilities (28 of 80) were significantly different, clinically, from the Canadian values. Canadian QALYS were 6% lower than those for the United States and 6% higher than those for the United Kingdom. When comparing the QALYS of each treatment with those of gemcitabine alone, the average percent change was + 6.8% for a U.S. scenario and -7.5% for a U.K. scenario compared with a Canadian scenario. Consequently, Canadian ICERS were approximately 5.4% greater than those for the United States and 8.6% lower than those for the United Kingdom. Based on the PSAS and compared with the Canadian threshold value, the minimum willingness-to-pay threshold at which the combination chemotherapy regimen of gemcitabine-capecitabine is the most cost-effective is $5,239 less than in the United States and $11,986 more than in the United Kingdom. Conclusions The use of non-country-specific tariffs leads to significant differences in the derived utilities, ICERS, and PSA results. Past Canadian EQ-5D-3L-based cost-effectiveness analyses and related funding decisions might need to be re-visited using Canadian tariffs.