In economic evaluation, the healthcare perspective has gradually given way to use of the societal perspective, as this perspective is often advocated for support in making optimal societal decisions. In practice, economic evaluations conducted from the societal perspective ignore, fail to measure and/or fail to monetize many of the costs that fall outside of the healthcare sector. To limit bias and increase decision-supportive power, researchers could strengthen their evaluations by adhering to a few basic principles. Five "pillars for the societal perspective" are proposed. First, who bears the cost and who does not is irrelevant. Second, it is imperative to consider including costs for sectors outside the healthcare sector. Third, both high frequent costs and costs with high unit prices should be considered. Fourth, double counting should be avoided. And fifth, researchers should reflect on choices related to costs, i.e. cost omission and problems with identifying, measuring, and valuing costs.
Keywords: Costs; Economic analysis; Economic evaluation; Intersectoral costs; Societal perspective.