The past and future of uncertainty in advanced illness: a systematic scoping review of underlying cognitive processes.

Background: To explain what cognitive capacity shapes uncertainty in advanced illness by identifying the types of evidence, mapping underlying cognitive processes to uncertainty, and outlining future directions for research and interventions.

Design: A systematic scoping review of mixed study designs was carried out following the methodological framework of Arksey and O'Malley (2005) and using qualitative content analysis.

Methods: PubMed, CINAHL, Embase, and PsycINFO were searched for original studies published in full and in English through December 2021 that reported on uncertainty in illness and related cognitions, cognitive science, or cognitive functions.

Results: After screening 978, 18 articles met the inclusion criteria for review. We found the cognitive capacity of mental time travel - to relive the past or foresee life in the future - interacted with episodic memory retrieval to inform decision-making, and prospection to imagine, predict or prepare for future outcomes to determine lesser or greater uncertainty in advanced illness.

Conclusions: Mental time travel is a fundamental cognitive function when the future is limited by an advanced illness, to review life as a meaningful narrative. The role of mental time travel to construct or make sense of uncertain futures inherent in advanced illness can inform theory and targets for intervention.