Cost–Utility Analysis of an Integrated CBT‐E Inpatient–Day Patient Treatment Pathway for Treatment‐Experienced Anorexia Nervosa in the United Kingdom

OBJECTIVE: To estimate lifetime cost-utility of an integrated enhanced cognitive behavioural therapy (CBT-E) inpatient-day patient pathway versus prolonged inpatient treatment-as-usual (TAU) for treatment-experienced adults with anorexia nervosa requiring intensive specialist treatment in the United Kingdom. METHOD: A five-state cohort Markov model estimated societal costs and quality-adjusted life years (QALYs) over a lifetime horizon using published clinical and UK economic inputs. Deterministic and probabilistic sensitivity analyses examined parameter uncertainty. RESULTS: The integrated pathway was associated with 23.30 modelled QALYs and costs of £234,379.69, compared with 18.64 QALYs and £831,105.70 for TAU: an incremental gain of 4.65 QALYs and savings of approximately £596,726. Findings were most sensitive to treatment responsiveness, relapse, readmission, and chronic disease costs. Probabilistic analyses were broadly consistent with the base-case findings under the specified assumptions. CONCLUSIONS: These pathway-level, model-based estimates suggest potential health and economic benefits for this intensive-care population. They depend on assumptions about relapse, recovery, and long-term service use and do not isolate the effect of CBT-E psychotherapy. Findings can inform research and service planning. Prospective comparative economic evaluation remains necessary.