ABSTRACT

Caffeine is widely used to counteract the effects of sleep loss. This systematic review and meta-analysis examined the impact of acute caffeine consumption on cognitive, physical, occupational and driving performance in sleep deprived/restricted individuals. 45 publications providing 327 effect estimates (EEs) were included in the review. Caffeine improved response time (44 EEs; g = 0.86; 95% CI: 0.53-0.83) and accuracy (27 EEs; g = 0.68; 95% CI: 0.48-0.88) on attention tests, improved executive function (38 EEs; g = 0.35; 95% CI: 0.15-0.55), improved reaction time (12 EEs; g = 1.11; 95% CI: 0.75-1.47), improved response time (20 EEs; g = 1.95; 95% CI: 1.39-2.52) and accuracy (34 EEs; g = 0.43; 95% CI: 0.30-0.55) on information processing tasks, and enhanced lateral (29 EEs; g = 1.67; 95% CI: 1.32-2.02) and longitudinal (12 EEs; g = 1.60; 95% CI: 1.16-2.03) measures of vehicular control on driving tests. Studies also typically indicated benefit of caffeine on memory (25 EEs), crystallized intelligence (11 EEs), physical (39 EEs) and occupational (36 EEs) performance. Ingestion of caffeine is an effective counter-measure to the cognitive and physical impairments associated with sleep loss.