A comprehensive review of official discount rates in guidelines of health economic evaluations over time: the trends and roots.

Background: The question of discounting in health economics is anything but settled, so much so that a section of the Health Technology Assessment (HTA) guidelines is devoted to it.

Objective: This study aimed to review the trend of the value of the official discount rates (DRs) of costs and health outcomes and their roots worldwide.

Methods: Four methods were combined to identify official DRs over time globally.