Severe malnutrition flags adolescents most likely to return after eating disorder admission

A study of more than 9,800 adolescent eating disorder admissions identifies severe malnutrition, anorexia nervosa and medical and psychiatric complications linked to readmission within 12 months.

Among adolescents hospitalised for an eating disorder, those with moderate or severe malnutrition, a diagnosis of anorexia nervosa and several common medical and psychiatric complications were more likely to be readmitted within a year, according to research published in the Journal of Adolescent Health. The findings suggest that the sickest patients at the point of admission may also be those who need the closest follow-up after discharge.

The study, led by Sarah J. Calardo of Nemours Children’s Hospital-Delaware in Wilmington, drew on the PEDSnet clinical research network and examined admissions to eight children’s hospitals between 2010 and 2024. Researchers looked at patients aged 12 to 21 who were treated for eating disorders including anorexia nervosa, bulimia nervosa and purging-related conditions, then assessed which clinical and demographic features were linked with rehospitalisation within 12 months. In the dataset used in the study, 7,505 patients were admitted once and 2,324 were readmitted within a year.

Malnutrition emerged as one of the clearest warning signs. Compared with patients without malnutrition, those classified as moderately malnourished had a higher chance of returning to hospital, while the risk was even greater for those with severe malnutrition. A primary diagnosis of anorexia nervosa also carried a higher odds of readmission than other eating disorder types. Female patients were more likely to be readmitted as well, according to the analysis.

The study also found that other medical and behavioural health problems mattered. Depression and anxiety were both associated with increased readmission risk, as were public insurance coverage, low potassium levels, low calcium levels and bradycardia, a slower-than-normal heart rate that can signal medical instability in patients with eating disorders. PubMed’s abstract for the paper additionally notes an association between readmission and orthostatic hypotension, a drop in blood pressure on standing.

The authors said identifying these risk factors early could help clinicians flag young people who are most likely to return to hospital and shape discharge planning, follow-up and post-discharge care. The study had limitations, however: body mass index data were available for only 78% of patients, limiting the assessment of malnutrition severity, and the analysis was confined to large children’s hospitals in the PEDSnet network. The researchers reported no conflicts of interest, and the work was supported through PEDSnet, a paediatric clinical research network funded by the Patient-Centred Outcomes Research Institute.