When chronic fatigue syndrome (CFS) was first identified in the 1980s, it was called the "yuppie flu," because most of its victims seemed to be upper-middle-class white professionals. But a recent study led by DePaul University psychology professor Leonard Jason, PhD, indicates that not only is CFS not restricted to yuppies, it's actually more common in people of color and those with lower levels of education and occupation.
Indeed, the work suggests that the problem may be much more common in the population as a whole than previous research suggested. The DePaul data indicate that 422 of every 100,000 Americans are affected, about twice the rate estimated by the Centers for Disease Control and Prevention (CDC).
The study is the first, according to Jason, to look for CFS with a random sample and a physical and psychiatric evaluation of an ethnically diverse population. He theorizes that earlier studies found lower rates because they studied only people already in contact with the health-care system.
"Many low-income individuals lack access to the health-care system, and many patients with fatigue drop out of the medical care system," he says.
The study also found the syndrome to be about 80 percent more common in women than in men, a rate that would make CFS one of the most common of serious health problems for women.
The study started with telephone interviews screening for possible CFS symptoms in a random sample of 28,673 adults. Sixty-five percent completed the interview. A battery of tests was given to the 166 respondents who had CFS-like symptoms and agreed to be tested, as well as a random sample of 47 respondents who did not have such symptoms. The testing included a structured psychiatric interview as well as a physical evaluation. A team of four physicians and a psychiatrist made the final diagnosis, finding that 32 of those with symptoms actually had CFS.
The DePaul work used the standard definition of CFS, revised by CDC in 1994. To be considered as having CFS, patients must have severe chronic fatigue for six months or longer. They must not have other medical conditions that might be causing the fatigue. They also must have four or more specific symptoms from a list that includes such items as substantial impairment in short-term memory or concentration, sore throat, tender lymph nodes and muscle pain.
The study was published in the Archives of Internal Medicine.