Feasibility, Acceptability and Outcomes of Group CBT-T: A Naturalistic Mixed-Methods Comparison With Individual CBT-T.

OBJECTIVE: This study aimed to evaluate the feasibility of implementing 10-session group cognitive behavioural therapy (CBT-Tg) in routine outpatient eating disorder care and to descriptively examine outcomes of CBT-Tg and individual CBT-T (CBT-Ti). METHOD: Using a naturalistic, non-randomised, mixed-methods design, this implementation study was conducted in a publicly funded outpatient eating disorder service. Adults eligible for outpatient eating disorder services selected CBT-Tg or CBT-Ti following intake. Feasibility outcomes included acceptability (treatment satisfaction, qualitative interviews, dropout), demand (uptake over time) and practicality (estimated clinician time). Effectiveness outcomes included eating-disorder psychopathology, measured by the eating disorder examination questionnaire (EDE-Q), and secondary outcomes assessing eating disorder symptoms, impairment and mood/anxiety during treatment and follow-up. RESULTS: Of 157 referred patients, 116 consented and initiated treatment. Satisfaction was high in both formats. Premature termination from CBT-Tg was 44.7%. Demand supported offering CBT-Tg in 8 of 9 three-month intervals. Estimated clinician time per enrolled patient was 4.3-5.7 h for CBT-Tg versus 8.0 h for CBT-Ti. EDE-Q global scores improved with very large within-group effects at end of therapy and were maintained through 6-month follow-up in both formats (CBT-Tg: g = -1.57 at end of therapy; g = -1.63 at follow-up; CBT-Ti: g = -1.97; g = -2.14). DISCUSSION: CBT-Tg appears feasible and acceptable in real-world outpatient care, with large and sustained improvements in eating disorder psychopathology and potential efficiency advantages relative to individual delivery. Findings support further evaluation in comparative and cost-effectiveness studies.