(Belief in) life after death impacts the utility of life before it - a difference in preferences or an artefact?

Abstract

In most of the religions the preservation of own, God-given, life is obligatory. The time-trade-off method (TTO) forces to voluntarily forego life years. We verify if this is a problem for the religious and how it impacts the TTO results. 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 used the belief in afterlife question to measure the religiosity on two levels: strong (definitely yes) and some (also rather yes), both about a third of the sample. The religious on average (yet, not statistically significant) spend more time doing TTO and consider it more difficult. The religious more often are non-traders: odds ratio (OR)=1.97 (strongly), OR=1.55 (rather); and less often consider a state worse-than-death: OR=0.67 (strongly), OR=0.81 (rather). These associations are statistically significant (p< 0.001) and hold when controlling for possible confounders. Strong religiosity abates the utility loss: in the additive approach by 0.136, in the multiplicative approach by the factor of 2.08 (both p< 0.001). Removing the effect of religiosity from the value set reduces the utility by 0.046 on average. The impact of religiosity seems to be a TTO-artefact rather than a true difference in preferences (testing this requires further analysis of, e.g., discrete-choice or visual analogue scale data). Non-Weltanschauung-biased estimates should rather be used in cost-utility analysis to drive resource allocation.