Systematic review of the effects of decision fatigue in healthcare professionals on medical decision-making.

Decision fatigue is the tendency towards making less effortful decisions as the cumulative mental burden of effortful decision-making increases. Health professionals working long shifts may be particularly vulnerable to decision fatigue. This preregistered systematic review (Prospero ID = CRD42021260081, no external funding) aims to synthesise the empirical evidence on decision fatigue in the healthcare context. Systematic searches across eight databases identified 14,740 records. N = 82 studies (72 quantitative, 1 qualitative, 1 review, 8 expert discussions) met the inclusion criteria (health professionals/trainees; medical decisions over time; healthcare context; any design). Study quality was assessed with the MMAT or relevant JBI checklist. Narrative synthesis revealed that 45% of cases that quantitatively assessed the decision fatigue hypothesis provided evidence of significant decision fatigue effects across diagnostic, test ordering, prescribing, and therapeutic decisions. Expert discussions confirmed healthcare professionals' recognition of decision fatigue as an important phenomenon. However, decision fatigue was inconsistently defined and inadequately operationalised, reflecting limitations in current theoretical understanding of the phenomenon. To address this, we propose a new definition for greater conceptual clarity and more consistent operationalisation in future research.' Future studies should prioritise the development and testing of different theoretical explanations for decision fatigue to improve understanding and facilitate the development of appropriate interventions.