Trajectories of Change in Body Weight During Inpatient Treatment for Anorexia Nervosa

Trajectories and predictive factors of weight recovery in patients with anorexia nervosa completing treatment. A latent class mixed model approach

BACKGROUND

Treatment of anorexia nervosa (AN) sometimes requires hospitalisation, which is often lengthy, with little ability to predict individual trajectory. Depicting specific profiles of treatment response and their clinical predictors could be beneficial to tailor inpatient management. The aim of this research was to identify clusters of weight recovery during inpatient treatment, and their clinical predictors.

METHODS

A sample of 181 inpatients who completed a treatment programme for AN was included in a retrospective study. A latent class mixed model approach was used to identify distinct weight-gain trajectories. Clinical variables were introduced in a multinomial logistic regression model as predictors of the different classes.

RESULTS

A four-class quadratic model was retained, able to correctly classify 63.7% of the cohort. It encompassed a late-rising, flattening, moderate trajectory of body mass index (BMI) increase (class 1), a late-rising, steady, high trajectory (class 2), an early-rising, flattening, high trajectory (class 3) and an early-rising, steady, high trajectory (class 4). Significant predictors of belonging to a class were baseline BMI (all classes), illness duration (class 2), and benzodiazepine prescription (class 3).

CONCLUSION

Predicting different kinetics of weight recovery based on routinely collected clinical indicators could improve clinician awareness and patient engagement by enabling shared expectations of treatment response.

Inpatient treatments for adults with anorexia nervosa: a systematic review of literature

PURPOSE

Anorexia nervosa (AN) is a mental disorder for which hospitalization is frequently needed in case of severe medical and psychiatric consequences. We aim to describe the state-of-the-art inpatient treatment of AN in real-world reports.

METHODS

A systematic review of the literature on the major medical databases, spanning from January 2011 to October 2023, was performed, using the keywords: "inpatient", "hospitalization" and "anorexia nervosa". Studies on pediatric populations and inpatients in residential facilities were excluded.

RESULTS

Twenty-seven studies (3501 subjects) were included, and nine themes related to the primary challenges faced in hospitalization settings were selected. About 81.48% of the studies detailed the clinical team, 51.85% cited the use of a psychotherapeutic model, 25.93% addressed motivation, 100% specified the treatment setting, 66.67% detailed nutrition and refeeding, 22.22% cited pharmacological therapy, 40.74% described admission or discharge criteria and 14.81% follow-up, and 51.85% used tests for assessment of the AN or psychopathology. Despite the factors defined by international guidelines, the data were not homogeneous and not adequately defined on admission/discharge criteria, pharmacological therapy, and motivation, while more comprehensive details were available for treatment settings, refeeding protocols, and psychometric assessments.

CONCLUSION

Though the heterogeneity among the included studies was considered, the existence of sparse criteria, objectives, and treatment modalities emerged, outlining a sometimes ambiguous report of hospitalization practices. Future studies must aim for a more comprehensive description of treatment approaches. This will enable uniform depictions of inpatient treatment, facilitating comparisons across different studies and establishing guidelines more grounded in scientific evidence.

LEVEL OF EVIDENCE

Level I, systematic review.

Recovery Trajectories in Adolescent Girls with Anorexia Nervosa

Background: This study aimed to document recovery trajectories among adolescents with anorexia nervosa (AN) based on three markers of remission, namely changes in body weight, food restriction, and excessive exercise, and to identify predictors of these trajectories. Methods: One hundred twenty-six adolescent girls (14.7 ± 1.3 years) were recruited during initial assessment visits at specialized eating disorder (ED) programs in five University Health Centers across the province of Quebec, Canada. z-BMI and AN symptom severity (food restriction and excessive exercise) were assessed at initial assessment visits and subsequently reassessed at each quarterly follow-up over a 12-month period to identify recovery trajectories. Results: Considering the three markers of remission, three distinct trajectories emerged: Group 1, rapid responders; Group 2, gradual responders; and Group 3, unstable responders. At initial visits, a difference between groups was found regarding the type of treatment (p = 0.01) and weight suppression (p = 0.02). Group 1 had a higher number of youths hospitalized than Group 2 and Group 3, and a greater weight suppression than Group 3. Furthermore, individuals with atypical AN were more likely to belong to Group 2 than to Group 1 and Group 3 (p < 0.0001). Conclusions: This study contributes to a better understanding of the heterogeneity of recovery trajectories in adolescent girls with AN.

A systematic review and meta-analysis of intensive treatment options for adults with eating disorders

Eating disorders (EDs) are complex conditions with one of the highest mortality rates among psychiatric illnesses. While outpatient evidence-based treatments for EDs in adults exist, there is often utilisation of more intensive interventions as part of treatment. However, a comprehensive analysis of the impacts of intensive treatment (inpatient, residential and day program) on physical and psychosocial outcomes is lacking. Thus, the current systematic review and meta-analysis aimed to investigate the effectiveness of intensive treatments in adults with EDs for the outcomes of body mass index (BMI), disordered eating, depression, and quality of life, as well as a moderation analysis investigating a range of clinical characteristics. Overall, 62 studies were included in the meta-analysis. The results revealed that intensive treatment in adults yielded significant improvements in BMI (for underweight patients), disordered eating, depression, and quality of life. Treatment setting, length of stay and geographical region of the study all served as moderators for disordered eating and depression. Nevertheless, given the high heterogeneity in the meta- and moderation analyses, these results should be interpreted with caution. Future high-quality research is needed to determine the most beneficial elements of intensive treatment (compared to outpatient) in adults with EDs.

Weight suppression and body mass index at admission interactively predict weight trajectories during inpatient treatment of anorexia nervosa

OBJECTIVE

Weight suppression refers to the difference between an individual's current and highest body weight at their current height. Higher weight suppression has been found to predict weight gain in both non-clinical samples and patients with eating disorders. Few studies also have reported interactive effects between weight suppression and current body mass index when predicting weight gain.

METHODS

In this retrospective study, we analyzed clinical records of inpatients with anorexia nervosa (N = 2191, 97% female) and tested whether weight suppression and body mass index at admission would interactively predict different weight trajectories during treatment.

RESULTS

Body weight increased non-linearly during treatment. Higher weight suppression predicted larger weight gain but the nature of this effect depended on body mass index at admission. In patients with a relatively low body weight at admission, those with high weight suppression started at a lower weight and showed a nearly linear and steeper weight gain than those with low weight suppression. In patients with a relatively high body weight at admission, those with high weight suppression started at a similar weight and showed a non-linear and larger weight gain than those with low weight suppression.

CONCLUSION

Findings further support that weight suppression is a robust predictor of weight gain in addition to-and in interaction with-current body weight. As weight suppression can easily be assessed at admission, it may help to anticipate treatment course and outcome in patients with anorexia nervosa.

Early within-person weight gain and variability during inpatient treatment for anorexia nervosa: Age-dependent effects on treatment outcome

OBJECTIVE

Early weight gain during inpatient treatment for anorexia nervosa (AN) is a dynamic process characterised by within-person variability that may be age-dependent. We examined whether age moderates the effect of within-person weight gain and variability on treatment outcome.

METHOD

Within-person level estimates of N = 2881 underweight adolescents and adults with AN for daily average weight gain (linear slope) and variability (root mean squared errors) were obtained using random-effects modelling. Between-person level regression analyses were calculated to assess effects on weight, eating disorder psychopathology and attaining normal body weight (body mass index [BMI]: 18.5-25 kg/m² ).

RESULTS

Higher weight gain during first 2 weeks of inpatient treatment predicted higher weight, lower drive for thinness and lower body dissatisfaction at discharge, but not lower bulimic symptoms. Moreover, it predicted a higher probability of discharge weight within normal range. Younger age was associated with stronger effects of early weight gain on weight, drive for thinness and body dissatisfaction at discharge. Weight variability was not associated with any outcome.

CONCLUSIONS

Age moderated effects of early weight gain on treatment outcomes, with larger effects for younger patients. Weight variability alone did not influence treatment across age and should be of lesser clinical concern during early inpatient treatment.

Early weight gain trajectories in first episode anorexia: predictors of outcome for emerging adults in outpatient treatment

BACKGROUND

Early response to treatment has been shown to be a predictor of later clinical outcomes in eating disorders (EDs). Specifically, early weight gain trajectories in anorexia nervosa (AN) have been shown to predict higher rates of later remission in inpatient treatment. However, no study has, as of yet, examined this phenomenon within outpatient treatment of first episode cases of AN or in emerging adults.

METHODS

One hundred seven patients with AN, all between the ages of 16 and 25 and with an illness duration of < 3 years, received treatment via the first episode rapid early intervention in eating disorders (FREED) service pathway. Weight was recorded routinely across early treatment sessions and recovery outcomes (BMI > 18.5 kg/m2 and eating psychopathology) were assessed up to 1 year later. Early weight gain across the first 12 treatment sessions was investigated using latent growth mixture modelling to determine distinct classes of change. Follow-up clinical outcomes and remission rates were compared between classes, and individual and clinical characteristics at baseline (treatment start) were tested as potential predictors.

RESULTS

Four classes of early treatment trajectory were identified. Three of these classes (n = 95), though differing in their early change trajectories, showed substantial improvement in clinical outcomes at final follow-up. One smaller class (n = 12), characterised by a 'higher' start BMI (> 17) and no early weight gain, showed negligible improvement 1 year later. Of the three treatment responding groups, levels of purging, depression, and patient reported carer expressed emotion (in the form of high expectations and low tolerance of the patient) determined class membership, although these findings were not significant after correcting for multiple testing. A higher BMI at treatment start was not sufficient to predict optimal clinical outcomes.

CONCLUSION

First episode cases of AN treated via FREED fit into four distinct early response trajectory classes. These may represent subtypes of first episode AN patients. Three of these four trajectories included patients with substantial improvements 1 year later. For those in the non-response trajectory class, treatment adjustments or augmentations could be considered earlier, i.e., at treatment session 12.

Prediction of eating disorder treatment response trajectories via machine learning does not improve performance versus a simpler regression approach

OBJECTIVE

Patterns of response to eating disorder (ED) treatment are heterogeneous. Advance knowledge of a patient's expected course may inform precision medicine for ED treatment. This study explored the feasibility of applying machine learning to generate personalized predictions of symptom trajectories among patients receiving treatment for EDs, and compared model performance to a simpler logistic regression prediction model.

METHOD

Participants were adolescent girls and adult women (N = 333) presenting for residential ED treatment. Self-report progress assessments were completed at admission, discharge, and weekly throughout treatment. Latent growth mixture modeling previously identified three latent treatment response trajectories (Rapid Response, Gradual Response, and Low-Symptom Static Response) and assigned a trajectory type to each patient. Machine learning models (support vector, k-nearest neighbors) and logistic regression were applied to these data to predict a patient's response trajectory using data from the first 2 weeks of treatment.

RESULTS

The best-performing machine learning model (evaluated via area under the receiver operating characteristics curve [AUC]) was the radial-kernel support vector machine (AUCRADIAL = 0.94). However, the more computationally-intensive machine learning models did not improve predictive power beyond that achieved by logistic regression (AUCLOGIT = 0.93). Logistic regression significantly improved upon chance prediction (MAUC[NULL] = 0.50, SD = .01; p <.001).

DISCUSSION

Prediction of ED treatment response trajectories is feasible and achieves excellent performance, however, machine learning added little benefit. We discuss the need to explore how advance knowledge of expected trajectories may be used to plan treatment and deliver individualized interventions to maximize treatment effects.

Latent trajectories of eating disorder treatment response among female patients in residential care

OBJECTIVE

Eating disorder (ED) treatment outcomes are highly variable from beginning to end of treatment; however, little is known about differential trajectories during the course of treatment. This study sought to characterize heterogeneous patterns of ED treatment response during residential care.

METHOD

Participants were adolescent girls and adult women (N = 360) receiving residential ED treatment for anorexia nervosa, bulimia nervosa, binge-eating disorder, other specified feeding or eating disorder, unspecified feeding or eating disorder, or avoidant/restrictive food intake disorder. Self-report symptom assessments were completed at admission, discharge, and approximately weekly throughout the residential stay to assess curvilinear patterns of change. Latent growth mixture modeling was applied to identify subgroups of patients with similar treatment response trajectories.

RESULTS

Three latent groups emerged, including gradual response (58.3%; steady improvements from admission to discharge), rapid response (23.9%; steep early improvements that were maintained through discharge), and low-symptom static response (17.8%; nearly nonclinical self-reported symptoms at admission that remained static through discharge). Groups differed on important clinical characteristics, such as body mass index, endorsement of compensatory behaviors, severity of global ED psychopathology at admission, and degree of symptom improvement by end of treatment.

DISCUSSION

Patients follow heterogeneous response patterns in residential ED treatment, and these patterns are associated with differential treatment outcome. Future work should explore whether these trajectories are associated with differential outcomes at follow-up and whether tailoring clinical intervention to a patient's trajectory type can improve treatment response.

Factors associated with weight gain in anorexia nervosa inpatients

OBJECTIVE

Nutrition restoration in inpatients with anorexia nervosa (AN) is a core element in treatment, enabling recovery of cognitive functions essential for psychological care. This study aims to identify factors associated with inpatient weight gain.

METHODS

Medical records from 107 inpatients aged 13-55 years with AN, hospitalized for more than 7 days at a specialized unit, were examined in a retrospective study. Weight evolution graphs were created for each patient and graded independently as optimal, moderate, and inadequate weight gain after 2 weeks and increasing, flat or decreasing weight in the first 2 weeks by expert clinicians. Driven by explicit hypotheses, bivariable analyses were carried out to detect relevant factors associated with weight gain during and after the first 2 weeks of admission.

RESULTS

Initial weight gain in the first 2 weeks of hospitalization and the introduction of a protocol harmonizing treatment procedures around rapid refeeding were strong factors associated with optimal weight gain after 2 weeks of hospitalization, whereas prior hospitalization in a psychiatric unit, diagnosis with binge-eating/purging subtype and age over 18 years were significantly associated with inadequate weight gain (p < 0.001-0.05).

CONCLUSION

To promote weight gain during hospitalization, clinicians should consider the following therapeutic measures: rapid refeeding strategies, renutrition protocols, and controlling purging behaviors.

LEVEL OF EVIDENCE

Level III, retrospective cohort study.

The independent and interacting effects of weight suppression and admission body mass index on treatment weight change in patients with anorexia nervosa or bulimia nervosa

OBJECTIVE

Weight suppression (WS) and body mass index (BMI) have predicted weight change in individuals with eating disorders, but the interaction between these variables is understudied. Furthermore, WS is usually measured as absolute WS-the numeric difference between current weight and highest past weight-overlooking the potentially important influence of how much a person weighed at their highest historical weight.

METHOD

The current study investigated the independent and interacting effects of BMI and two measures of WS at admission on residential treatment weight change. WS measures included absolute WS and the relative WS index, the percentage of total body weight lost from highest past weight. Participants were women with anorexia nervosa (n = 357) or bulimia nervosa (n = 293) who provided complete data, 87% of the eligible treatment sample.

RESULTS

In both diagnostic subsamples, BMI, absolute WS, and the relative WS index all significantly predicted weight change. The interaction between BMI and WS predicted weight change, but only when the relative WS index was used.

DISCUSSION

Results highlight the potential importance of considering an individual's weight and weight history when predicting their treatment weight change and support the importance of utilizing both methods of calculating WS in future research.