Integrating environmental considerations in HTA: The strategy of the Institut National d'Excellence en Santé et Services Sociaux (INESSS).

Executive functioning and episodic memory begin to display subtle declines in midlife (; ). While initially modest, these changes tend to accelerate in older age (; ). Importantly, there are large individual differences in these trajectories: some adults experience greater losses, whereas others maintain relatively stable levels well into old age (; ). Overall, cognitive aging manifests as a gradual change, yet we still know little about whether these changes co-occur with changes in people’s everyday positive and negative experiences. Daily events are important determinants of well-being. They reflect active engagement with the environment, capturing experiences that provide reinforcement, as well as daily demands that require adjustment (). Positive events are minor, favorable transactions with the environment that usually result in upticks in positive emotions (). Stressors, in contrast, encompass the routine challenges of everyday life, such as arguments, unexpected disruptions, and ongoing chronic strains (). Importantly, unlike perceived stress or feelings of stress, stressful events are external to a person and represent occurrences and conditions in the environment that place demands on the individual (). Although both positive events and stressors are thought to change in their frequency with age (; ), the evidence remains mixed, and little is known about how such shifts unfold in tandem with cognitive aging. According to socioemotional selectivity theory, as people grow older, they increasingly prioritize emotionally meaningful relationships and activities while avoiding situations that might generate stress (; ; ). By steering clear of potentially stressful contexts, however, older adults may also limit their opportunities for positive experiences. Indeed, longitudinal data from the VA Normative Aging Study have shown that exposure to both stressors and positive events decreased with advancing age (). While this longitudinal pattern has been corroborated for stressors using the Midlife in the United States Study (MIDUS; ), other longitudinal findings for positive events are missing. Cross-sectional studies are mixed, with studies focusing on older adulthood showing older age being related to fewer positive events (; ), while lifespan samples tend to show the opposite effect (; ). Importantly, these findings reflect average trends; there are marked individual differences in both the rate and direction of age-related change ().