Some professions have to worry about absenteeism—employees not reporting to work. But in the medical field, researchers are calling attention again to the troublesome trend of "presenteeism" among health care workers, and its implications.

It's common knowledge that medical residents often work well beyond the 30-consecutive-hour limit—and sometimes put in more than 80-hour workweeks. Now, a new analysis shows that in addition to fatigue, many residents treating patients are sick themselves.

Of 537 medical residents who responded to a 2009 survey, about 58 percent said they had worked while sick at least once during the previous year. Nearly a third said they had done so at least twice. "Residents may work when sick for several reasons, including misplaced dedication, lack of an adequate coverage system or fear of letting down teammates," the authors of the new analysis wrote. The results were published online in a research letter September 14 in JAMA, Journal of the American Medical Association.

"We noticed that if residents called in sick, people questioned their motives; and if they came in sick people questioned their judgment," Anupam Jena, a resident at Massachusetts General Hospital and co-author of the analysis, said in a prepared statement. At five of the dozen hospitals in the survey, more than 90 percent of residents respondents reported having worked while sick. "Hospitals need to build systems and create a workplace culture that enables all caregivers, not just residents, to feel comfortable calling in sick," Vineet Arora, an associate professor and associate director of the internal medicine residency program at the University of Chicago and study co-author, said in a prepared statement. "Their colleagues and their patients will thank them," she noted.

Residents were more likely to have worked while sick in their second year post graduation from medical school than in their first, the researchers found.

It might be little wonder that frequently sleep deprived physicians get sick, and because of their busy schedules, more than half (about 53 percent) of the residents surveyed had no time to see a doctor themselves.

"The real issue here is what is best for patient care," Jena said. "Knowing your patient well doesn't compensate for being infectious." He suggests that for residents, "If it's contagious—for example a viral cold—or if it's enough to cloud your judgment, stay home."

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