Effects of acute caffeine consumption following sleep loss on cognitive, physical, occupational and driving performance: A systematic review and meta-analysis.
Level 1 - systematic review of randomized trials
Systematic review and meta-analysis of experimental trials
PubMed 31837359 · doi:10.1016/j.neubiorev.2019.12.008
What was done
A systematic review and meta-analysis evaluating the impact of acute caffeine consumption on cognitive, physical, occupational, and driving performance in sleep-deprived or sleep-restricted individuals across 45 publications providing 327 effect estimates (EEs).
What was found
Caffeine intake improved attention 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), executive function (38 EEs; g = 0.35; 95% CI: 0.15-0.55), information processing reaction time (12 EEs; g = 1.11; 95% CI: 0.75-1.47), 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). It enhanced driving lateral control (29 EEs; g = 1.67; 95% CI: 1.32-2.02) and longitudinal control (12 EEs; g = 1.60; 95% CI: 1.16-2.03). Benefits were also noted for memory (25 EEs), crystallized intelligence (11 EEs), physical (39 EEs), and occupational (36 EEs) performance, though specific effect sizes for these latter categories were not detailed in the abstract.
Why it matters
This review provides quantitative evidence that caffeine effectively mitigates performance impairments caused by sleep loss, particularly for critical tasks such as vehicle control and rapid information processing.
Limits
The abstract does not report the total human sample size, doses administered, timing of administration, or participant characteristics. Quantitative effect sizes were omitted from the abstract for memory, physical, occupational, and crystallized intelligence outcomes, and the degree or type of sleep loss (total deprivation vs. restriction) was not differentiated.