Treatment outcome in a specialized unit for adults with severe and extreme anorexia nervosa at one-year follow up

Abstract

Background: Inpatient treatment successfully increases body weight and decreases eating disorder and associated symptoms in patients with anorexia nervosa (AN). However, relapse rates are high, particularly within the first year after discharge.

Methods: We examined treatment outcome one year after discharge in adults with AN (N = 80, 2 males; BMI at admission: M = 13.2 kg/m², SD = 1.79) who received treatment in a specialized inpatient unit for AN patients with severe underweight (body mass index < 15 kg/m²) and/or excessive purging or exercising.

Results: From admission to discharge, body weight and self-reported life satisfaction significantly increased and self-reported eating disorder symptoms, depressive symptoms, and compulsive exercise significantly decreased. From discharge to follow up, life satisfaction and body weight decreased, and eating disorder symptoms, depressive symptoms, and compulsive exercise increased, although 87% of patients indicated to have received some kind of eating disorder treatment in the past six months. At follow up, the majority of patients indicated that they regularly ate three meals per day in the past week, including consumption of high-calorie, formerly forbidden foods. However, only a minority of patients indicated that they adhered to the hospital's guidelines on portion sizes. Patients' self-reported desired body weight at follow up was significantly higher than their current body weight.

Conclusions: While inpatient treatment results in substantial improvements that are partially maintained after discharge, severe and extreme cases of AN require more long-lasting, alternating treatment approaches (e.g., interval treatment) to ensure long-term recovery.

Keywords: Body mass index; Eating disorders; Inpatient treatment; Psychotherapy; Severe and enduring anorexia nervosa.

Fig. 1

Participant flow

Fig. 2

Mean A body mass index and scores on the B Eating Disorder Examination–Questionnaire, C Commitment to Exercise Scale, D Beck Depression Inventory–Revised, and E Satisfaction With Life Scale at admission, discharge, and follow up. Error bars indicate standard error of the mean. The black lines are second-order polynomial fit lines indicating non-linear change over time and the grey-shaded areas represent 95% confidence intervals. Note that numbers in the different panels are not comparable because of different scaling and scoring of variables

Fig. 3

Changes across admission, discharge, and follow up in A body mass index (BMI) as a function of BMI at admission and B scores on the Beck Depression Inventory–Revised as a function of illness duration. The lines are second-order polynomial fit lines indicating non-linear change over time and the grey-shaded areas represent 95% confidence intervals. Note that high and low refer to ± 1 SD from the sample’s mean BMI at admission and illness duration, respectively. These values are arbitrarily chosen for visualizing the interaction effect time² × BMI at admission and time² × illness duration in the robust mixed models. That is, BMI at admission and illness duration were used as continuous variables in these analyses and not categorized into groups