Purging behavior in anorexia nervosa and eating disorder not otherwise specified: A retrospective cohort study

Purging behavior in eating disorders is associated with medical risks. We aimed to compare remission rates in purging and non-purging females with anorexia nervosa (AN) and eating disorder not otherwise specified (EDNOS) in a large retrospective single center cohort. A total of 339 patients with AN and 266 patients with EDNOS were included in the study. The proportion of subjects with purging behavior at least once a week during the last 3 months was similar in the two groups: 22% in AN and 24% in EDNOS. Remission was defined by a goal weight ≥ 85% of ideal body weight and no reported purging behavior in the last 6 months. The median time from onset to remission for patients with AN was 7 years for the non-purging vs. 11 years for the purging patients. The purging AN patients with both vomiting and laxative abuse displayed the poorest course. Among EDNOS patients, the time to remission was also significantly longer for purging patients compared to non-purging patients. Thus, in line with previous studies, we found that purging behavior is associated with delayed time to remission in treatment-seeking AN and EDNOS patients. This study provides evidence to support the retention of the diagnostic sub-typing in AN.