and home life also become blurry. People spend an average of 4.5 hours doing work at home each week, with 20 percent spending 10 or more hours working at home. This could represent a cycle in which people are less productive at work because they're tired, so they bring work home, only to have it interfere with their sleep.
One of the professions where sleepiness makes an obvious (and sometimes dangerous) dent in work performance is the medical field. Researchers have studied the extended hours of medical professionals and found that losing sleep has a big impact on their work quality. For example, when on-call residents work overnight, they have twice as many attention failures, commit 36 percent more serious medical errors and report 300 percent more medical errors that lead to death than those who work a 16-hour shift. In one study, researchers capped the workweek of medical school interns at 80 hours and found that these interns had less than half the rate of failures in attention than did the interns who worked more than 80 hours.