Alternative community-based models of care for young people with anorexia nervosa: the CostED national surveillance study

Background: Evidence suggests investing in specialist eating disorders services for young people with anorexia nervosa could have important implications for the NHS, with the potential to improve health outcomes and reduce costs through reductions in hospital admissions. Objective(s): The primary aim was to evaluate the cost and cost-effectiveness of alternative community-based models of service provision for young people with anorexia nervosa and to model the impact of potential changes to the provision of specialist services. Design: Observational, surveillance study using the Child and Adolescent Psychiatry Surveillance System. Setting: Community-based secondary or tertiary child and adolescent mental health services (CAMHS) in the UK or Republic of Ireland. Participants: 298 young people aged 8 to 17, in contact with CAMHS for a first episode of anorexia nervosa according to DSM-5 diagnostic criteria. Interventions: Community-based specialist eating disorders services and generic CAMHS. Main outcome measures: Children’s Global Assessment Scale (CGAS; primary) and percentage of median expected body mass index for age and gender (%mBMI; secondary) assessed at baseline, 6 and 12-months. Data sources: Data collected by clinicians from clinical records. Results: There were no significant differences in total costs between young people initially assessed in specialist eating disorders services and young people initially assessed in generic CAMHS. However, adjustment for baseline covariates resulted in observed differences favouring specialist services (costs lower, on average), due to significantly poorer clinical status of the specialist group at baseline. At 6-month follow-up, mean %mBMI was significantly higher in the specialist group, but no other significant differences in outcomes were evident. Cost-effectiveness analyses suggest that initial assessment in a specialist service has a higher probability of being cost-effective than initial assessment in generic CAMHS, for CGAS and %mBMI. However, no firm conclusion can be drawn without knowledge of society’s willingness to pay for improvements in these outcomes. Decision modelling did not support the hypothesis that changes to the provision of specialist services would generate savings for the NHS, with results suggesting that cost per ten-point improvement in CGAS (improvement from one CGAS category to the next) varies little as the percentage of participants taking the specialist or generic pathway is varied. Limitations: Follow-up rates were lower than expected, but the sample was still larger than RCTs carried out in this population in the UK have been able to achieve to date, and exploration of the impact of missing cost and outcome data produced very similar results to the main analyses. Conclusions: The results of this study suggest that initial assessment in a specialist eating disorders service for young people with anorexia nervosa may have a higher probability of being cost-effective than initial assessment in generic CAMHS, although the associated uncertainty makes it hard to draw firm conclusions. Whilst costs and outcomes were similar, young people in specialist services were more severely ill at baseline, suggesting specialist services were achieving larger effectiveness gains without the need for additional expenditure. The results did not suggest that providing more specialist services would save money for the NHS, given similar costs and outcomes, so decisions about which service type to fund could be made with reference to other factors, such as the preferences of patients and carers. Future work: Data on measures of quality of life capable of generating quality adjusted life years are needed to confirm the cost-effectiveness of specialist services. Study registration: ISRCTN12676087 Funding details: NIHR HS&DR Programme (11/1023/17).