A multicenter audit of outpatient care for adult anorexia nervosa: Symptom trajectory, service use, and evidence in support of "early stage" versus "severe and enduring" classification.

Background: We explored the utility of "staging" anorexia nervosa (AN) by duration of illness and psychological wellbeing. We also investigated 12-month symptom trajectories and service usage in a large cohort of patients with AN assessed for outpatient treatment.

Method: We conducted secondary analyses on data from a multisite clinical trial of adults with AN (n = 187) recruited from 22 NHS England specialist eating disorder (ED) services into a digital treatment augmentation study. Clinical outcomes and service use were measured at postintervention (six weeks), 6 and 12 months. We grouped patients into two categories: "early stage" (illness duration <3 years; n = 60) and "severe and enduring" stage (SE-AN; n = 41) indicated by distress (Depression Anxiety and Stress Scales, DASS ≥60) and illness duration (≥7 years).

Results: At 12 months, patients reported large improvements in body mass index, small to moderate improvements in ED symptoms, mood, and work/social adjustment, and 23.6% met criteria for recovery. However, patients classified as SE-AN reported higher rates of accessing intensive services, higher ED symptomatology, and poorer work/social adjustment at baseline, and lower rates of improvement in work/social adjustment at 12 months compared to "early stage" respondents.

Discussion: Although present findings suggest overall symptomatic improvements, exploratory results highlight marked differences in course and service use between people at different stages of AN, suggesting a need to consider staging for clinical decision-making. Further research differentiating between clinical subtypes of AN and adoption of a more personalized approach may ensure that services and care pathways better fit patient needs.