Q&A: Predicting Lasting Recovery from Anorexia Nervosa

Q: Do you know of any clinical markers available during hospitalization for anorexia nervosa (AN) that predict how enduring recovery is likely to be? (BD, Flint, MI).

A: The search for predictive markers of long-term recovery from AN during hospitalizations has been vexing, with a number of contradictory and non-replicated findings emerging from various studies. The most consistent finding predictive of post-discharge outcome has been the body mass index (BMI) at discharge; that is, the higher the BMI, the better the outcome. Although the amount of absolute weight gain during hospitalization and the length of stay have been also suggested as markers, studies have not shown these parameters to be strongly associated with outcomes.
Recently, a group at the Laureate Research Institute and Clinic in Tulsa reported that the rate of weight gain during hospitalization was correlated with outcomes one year following hospital discharge. Specifically, even after adjusting for potentially confounding factors, these researchers found that clinical deterioration occurred significantly less often among participants who gained more than  0.8 kg(1.76 lb)/week than among those who gained less than this amount. Based on data from 79 patients followed for a year, 29% of those with weight gain at or above the 0.8 kg/wk level showed clinical deterioration, compared to 53% of those whose rate of weight gain fell below this mark (Int J Eating Disord 2009; 42:301). Facilities treating patients with AN should keep in mind that the rate of weight gain may be an indicator not only of how well patients might be expected to do in the long run, but may also serve as a parameter by which to measure program quality.

– J.Y.