Effects of interval-based inpatient treatment for anorexia nervosa: An observational study

Abstract

Objective: After inpatient treatment for anorexia nervosa (AN), many patients relapse and need to be readmitted. To obtain a sustained improvement, a pre-planned multistep inpatient procedure might help to improve the patient's skills in dealing with symptoms and transdiagnostic problems, thus decreasing symptoms of AN. However, no data have been reported for such interval treatment yet. Therefore, this study examined effects of interval treatment in inpatients with AN.

Method: Data of adult women with AN (N = 304) who received inpatient treatment and either received interval treatment (n = 179) or not (n = 125) were analyzed. Of these, 225 patients completed a follow up measurement after an average of 25 months. Treatment outcome variables were body mass index and subscales of the Eating Disorder Inventory-2 at admission, discharge, and follow up.

Results: Across measurements, the interval treatment group had larger increases in body mass index and larger decreases in drive for thinness and binge/purge symptoms than the no interval treatment group. These differences did not seem to be driven by longer treatment duration.

Discussion: Our data suggest that interval treatment for AN is effective and may even be superior to conventional single inpatient treatment. Given the observational nature of this study, however, controlled studies are necessary to corroborate these findings.

Keywords: anorexia nervosa; inpatient treatment; intermittent treatment; interval treatment; weight gain.

FIGURE 1

Mean body mass index (BMI) with second‐order polynomial fit lines. Error bars represent the standard error of the mean. Panel (a) displays BMI as a function of treatment groups. Panel (b) displays BMI as a function of treatment groups and total treatment duration. Short and long total treatment durations are based on a median split for which mean total treatment duration was 57 and 224 days in the no interval treatment group and 85 and 214 days in the interval treatment group. Note, however, that analyses are based on the continuous variable of total treatment duration and not based on group categorization, which only serves the purpose of visualizing the interaction effect

FIGURE 2

Mean subscale scores of the Eating Disorder Inventory‐2 (EDI‐2) with second‐order polynomial fit lines. Error bars represent the standard error of the mean. Panel (a) displays mean scores of the drive for thinness subscale, panel (b) displays mean scores of the bulimia subscale, and panel (c) displays mean scores of the body dissatisfaction subscale as a function of treatment groups