Adherence of nutritional support prescriptions to clinical practice guidelines in patients with anorexia nervosa

Background: nutritional support (NS) is a core element in the treatment of underweight patients with anorexia nervosa (AN). Objective: to analyze the adherence of NS prescriptions to clinical practice guidelines (CPGs) for AN patients and to compare the effectiveness, safety, and cost of NS according to adherence. Methods: this retrospective observational study included AN patients admitted to an Eating Disorders Unit between January 2006 and December 2009 and followed until December 2014. NS prescriptions were compared with guidelines published by the American Psychiatric Association (APA), the National Institute for Clinical Excellence (NICE), and the Spanish Ministry of Health and Consumption (SMHC). Adherence was defined as percentage of hospitalizations that followed all recommendations. Results: adherence to APA and NICE/SMHC was observed in 10.2% and 73.4%, respectively, of the total of 177 hospitalizations. Body weight and body mass index were higher at admission in the NICE/SMHC adherence versus non-adherence group (p < 0.001). Weight gain rate during hospitalization was higher (p = 0.009) in "APA adherence" (135.5 g/day) versus "non-adherence" (92.1 g/day) group. Hospital stay was significantly shorter (p = 0.025) in "NICE/SMHC adherence" (39.5 days) versus "non-adherence" group (50.0 days). NICE/SMHC adherence was associated with lower costs (p = 0.006). Conclusions: NS prescriptions for anorexic patients more frequently followed NICE/SMHC than APA recommendations. Over the short-term, APA adherence was associated with improved weight gain. Patients adhering to NICE/SMHC recommendations had shorter hospital stay and reduced costs, likely due to their more favorable nutritional status at admission.