Objective: To explore the relationship between junior doctors' long working hours and their performance in a variety of cognitive and clinical decision-making tests. Also, to consider the implications of performance decrements in such tests for healthcare quality.
Design: A within-subject design was used to eliminate variation related to individual differences. Each participant was tested twice, once post call and once rested. At each session, participants were tested on cognitive functioning and clinical decision-making.
Setting: The study was based on six acute Irish hospitals during 2008.
Participants: Thirty junior hospital doctors, ages ranged from 23 to 30 years; of them, 17 of the participants were female and 13 were male. Measures Cognitive functioning was measured by the MindStreams Global Assessment Battery (NeuroTrax Corp., NY, USA). This is a set of computerized tests, designed for use in medical settings, that assesses performance in memory, executive function, visual spatial perception, verbal function, attention, information processing speed and motor skills. Clinical decision-making was tested using Key Features Problems. Each Key Features Problem consists of a case scenario and then three to four questions about this scenario. In an effort to make it more realistic, the speed with which participants completed the three problems was also recorded.
Results: Participants' global cognitive scores, attention, information processing speed and motor skills were significantly worse post call than when rested. They also took longer to complete clinical decision-making questions in the post-call condition and obtained lower scores than when rested.
Conclusions: There are significant negative changes in doctors' cognitive functioning and clinical decision-making performance that appear to be attributable to long working hours. This therefore raises the important question of whether working long hours decreases healthcare quality and compromises patient safety.