Purpose: In most religions, the preservation of one's own, God-given, life is considered obligatory, while the time trade-off method (TTO) forces one to voluntarily forego life years. We sought to verify how this conflict impacts TTO-results among the religious.
Methods: We used the data from the only EQ-5D valuation in Poland (2008, three-level, 321 respondents, 23 states each)-a very religious, mostly Catholic country. We measured the religiosity with the belief in afterlife question on two levels: strong (definitely yes) and some (also rather yes), both about a third of the sample.
Results: The religious more often are non-traders, unwilling to give up any time in exchange for quality of life: odds ratio (OR) equal to 1.97 (strong religiosity), OR 1.55 (some religiosity); and less often consider a state worse than death: OR 0.67 (strong), OR 0.81 (some). These associations are statistically significant ([Formula: see text]) and hold when controlling for possible demographic confounders. Strong religiosity abates the utility loss: in the additive approach by 0.14, in the multiplicative approach by the factor of 2.1 (both [Formula: see text]), especially among the older. Removing the effect of religiosity from the value set reduces the utility by 0.05 on average.
Conclusion: The results may stem from a true difference in preferences or be a TTO-artifact and would vanish for other elicitation methods. Juxtaposing our findings with comments from respondents in other studies suggests the latter. Therefore, this Weltanschauung effect should be removed in cost-utility analysis.
Keywords: Health-related quality of life; Life after death; Preference elicitation; Religion; Time trade-off; Utility.