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.