A May 2021 study by Michigan State University found,
"that sleep deprivation impaired performance on both types of tasks and that having caffeine helped people successfully achieve the easier task. However, it had little effect on performance on the placekeeping task for most participants,"
"Caffeine may improve the ability to stay awake and attend to a task, but it doesn't do much to prevent the sort of procedural errors that can cause things like medical mistakes and car accidents."
"Caffeine increases energy, reduces sleepiness and can even improve mood, but it absolutely does not replace a full night of sleep … Although people may feel as if they can combat sleep deprivation with caffeine, their performance on higher-level tasks will likely still be impaired. This is one of the reasons why sleep deprivation can be so dangerous."
"If we had found that caffeine significantly reduced procedural errors under conditions of sleep deprivation, this would have broad implications for individuals who must perform high stakes procedures with insufficient sleep, like surgeons, pilots and police officers,"
"Instead, our findings underscore the importance of prioritizing sleep."