麻豆果冻传媒

For Release: April 10, 2010

STANFORD, Calif.聽- Diagnostic cutoffs for聽anorexia nervosa听补苍诲听bulimia nervosa聽may be too strict, a study from the Stanford University School of Medicine and Lucile Packard Children鈥檚 Hospital has found. Many patients who do not meet full criteria for these diseases are nevertheless quite ill, and the diagnosis they now receive, 鈥淓ating Disorder Not Otherwise Specified,鈥� may delay their ability to get treatment.

鈥淭here鈥檚 mounting evidence that we should reconsider the EDNOS categorization for young people,鈥� said聽Rebecka Peebles, MD, the study鈥檚 primary author. The EDNOS diagnosis has become a 鈥渕osh pit,鈥� lumping dissimilar patients into a single category that gets poor recognition from clinicians and health insurers, she said. 鈥淚t is a bit misleading to patients 鈥� it can make them feel like they don鈥檛 have a real eating disorder,鈥� said Peebles, an instructor in pediatrics at Stanford and an adolescent medicine specialist with the聽Comprehensive Eating Disorders Program at Packard Children鈥檚 Hospital.

Anorexia and bulimia affect about 1 percent and between 2 and 5 percent of teen girls, respectively, and both diseases are more common among females than males. Their diagnostic criteria were developed by expert consensus, without the benefit of studies to track patients鈥� health. An anorexia diagnosis is now based on being at less than 85 percent of the expected body weight, loss of menstrual periods for at least three months and fear of weight gain despite being dangerously thin. Bulimia patients repeatedly binge on large quantities of food, then 鈥減urge鈥� calories by vomiting, abusing laxatives or diuretics, or overexercising. Both diseases can cause serious long-term health problems, and severe cases may lead to death.

Peebles鈥� team conducted the first-ever large study to ask whether adolescents with EDNOS are less ill than those who meet the full diagnostic criteria for anorexia or bulimia. The research, which will be published online April 12 in Pediatrics, examined records from all 1,310 female patients treated for eating disorders at Packard Children鈥檚 between January 1997 and April 2008. They verified patients鈥� diagnoses of anorexia, bulimia or EDNOS, and created categories of 鈥減artial anorexia nervosa鈥� and 鈥減artial bulimia nervosa鈥� to analyze patients who barely missed cutoffs for these diseases. 鈥淥ur purpose was to ask if the diagnostic criteria now in use are really separating out the sickest of the sick,鈥� Peebles said. Patients鈥� conditions were assessed by noting signs of malnutrition 鈥� such as low heart rate, low blood pressure, low body temperature, low blood levels of potassium and phosphorus 鈥� and long QT interval (an electrocardiogram measurement linked to risk of sudden cardiac death).

Nearly two-thirds of the patients studied had EDNOS. As the researchers suspected, the EDNOS category acted as a catchall; patients with partial anorexia were more similar to those with full-blown anorexia than to other EDNOS patients with partial bulimia, for instance. In addition, 60 percent of EDNOS patients met medical criteria for hospitalization and this group was, on average, sicker than patients diagnosed with full-blown bulimia. The sickest EDNOS patients were those who had dropped more than 25 percent of their body weight before diagnosis. These patients had been overweight and had lost weight too quickly and dangerously in order to end up at what is typically considered a normal weight.

鈥淧eople were initially just patting them on the back for their weight loss,鈥� Peebles said. 鈥淚t often took months or years for others to realize that what they were doing didn鈥檛 seem healthy.鈥� Despite their normal body weights, this group was in some ways worse off than underweight patients diagnosed with anorexia, she added. 鈥淭hey manifested criteria of severe malnutrition.鈥� In sum, Peebles said, the study suggests that medical criteria for eating disorders should be re-evaluated. Though the current diagnostics cover the right general areas, 鈥渨e erroneously treat these criteria in a very black-and-white way,鈥� she said. 鈥淢any practitioners interpret these to believe that menses has to be lost to get an anorexia diagnosis; bulimics have to binge and purge at least two times a week for three months. These findings illustrate the arbitrary nature of those cutoffs.鈥�

The issue is particularly urgent because many health insurers offer less coverage for EDNOS treatment than for treatment of anorexia or bulimia. And doctors and parents may be falsely reassured if a child is labeled with EDNOS. 鈥淚 think that when parents walk out of a doctor鈥檚 office having heard their kid doesn鈥檛 meet criteria for anorexia, they鈥檙e relieved,鈥� Peebles said. But they shouldn鈥檛 let their guard down: in many cases, the child鈥檚 disturbed eating patterns still need treatment. The Stanford collaborators on Peebles鈥� team were Jenny Wilson, MD, a resident in pediatrics, and聽James Lock, MD, PhD, professor of psychiatry and behavioral sciences and of pediatrics. The study was funded by the Stanford Pediatric Research Fund and the American Heart Association, with additional support from the Stanford Medical Scholars Research Program and the National Institutes of Health.

Authors

Robert Dicks
(650) 497-8364
rdicks@stanfordchildrens.org