Points to consider for incorporating climate impacts into health economic evaluation.

The EQ-5D-3L is among the most widely used measures of health-related quality of life (HRQoL). It describes health states across five dimensions (mobility, self-care, usual activities, pain/discomfort, and anxiety/depression), with three levels of severity per dimension (no problems, moderate problems, severe problems) []. This 5-dimension, 3-level structure enables the distinction of 243 unique health states, denoted by 5-digit codes representing the level of problems on each dimension. For instance, health state 12313 indicates no problems with mobility (level 1), some problems with self-care (level 2), inability to perform usual activities (level 3), no pain/discomfort (level 1), and extreme anxiety or depression (level 3). To enable the calculation of Quality Adjusted Life Years (QALYs), country-specific value sets have been developed. These sets assign quality weights to each EQ-5D-3L health state based on preference-based trade-offs between quality and duration of life, anchored on a health-utility scale where 0 represents immediate death and 1 represents full health. Values below 0 indicate health states considered worse than death (WTD). For the Netherlands, such a value set has been available since 2006 [], which has been extensively employed in health economic evaluations and is among the recommended instruments for cost-utility analyses in the country []. However, the current Dutch EQ-5D-3L value set, published 18 years ago and based on data collected 21 years ago, may no longer accurately reflect contemporary Dutch population preferences. The Netherlands has undergone significant demographic changes during this period, and societal preferences may have evolved independently of these demographic shifts. Furthermore, methodologies for eliciting health-state preferences have substantially advanced since the current value set’s publication.