Title: The Cost-Effectiveness of models of care for young people with Eating Disorders
Funder: Department of Health (England)

Abstract: DESIGN: The study will involve the development of a decision analytic model to explore the impact of potential changes to the configuration of community-based services for child and adolescent anorexia nervosa (AN) on relative cost and cost-effectiveness. The model will be populated with data on incident cases of child and adolescent AN in England Wales and Northern Ireland collected over a 12-month period via a naturalistic surveillance study using the Child and Adolescent Psychiatric Surveillance System (CAPSS). INCLUSION CRITERIA: Children and adolescents aged 8-18 in contact with community-based mental health services and meeting criteria for AN or eating disorder not otherwise specified (EDNOS) that closely resemble anorexia nervosa (EDNOS-AN). Case definition criteria will be designed to encourage over-reporting and will be based on modified DSM–IV and ICD–10 criteria for eating disorders. BASELINE DATA: Upon notification from CAPSS of a new case of child and adolescent AN in the British Isles the notifying clinician will be sent a brief questionnaire to confirm eligibility of the case and to support the categorisation of the model of service delivered and the geographical mapping of models of care across the British Isles. Classification will focus on the service undertaking the initial assessment and will include tertiary specialist child and adolescent eating disorder service (CAEDS) specialist child and adolescent mental health service (CAMHS) teams based in generic secondary care CAMHS but containing a specialist eating disorder component and generic secondary (non-specialist) CAMHS services.FOLLOW-UP DATA: 9-months and 18-months after notification the notifying clinician and/or the notifying service of cases in England Wales and Northern Ireland will be re-contacted by phone to collect anonymised information on health service use (frequency and length of inpatient admissions and number of hospital or community based outpatient contacts) and outcomes (age adjusted percentage median body mass index Health of the Nation Outcome Score for Children and Adolescents (HoNOSCA) and outcome category according to the Morgan and Russell criteria. A brief telephone-based questionnaire will be designed and tested for use with a treating clinician.SAMPLE SIZE: Notification is estimated to be approximately 1200 cases over 12 months. After exclusions due to insufficient data reporting errors and duplicates a baseline sample size for the British Isles is estimated to be 734 of which 675 will be located in England Wales and Northern Ireland. Assuming an 85% response rate at first follow-up and a 75% response rate at second follow-up the expected final follow-up sample is 430.ANALYSIS: (1) Incidence of child and adolescent AN - Incidence will be calculated as the number of cases as a proportion of the total number of children of that age in the population (UK plus Republic of Ireland) expressed as per 100000 population. (2) Cost of child and adolescent AN - Data on inpatient and outpatient health service use will be used to calculate the 18-month cost of all cases followed-up in England Wales and Northern Ireland and to assess the relative cost of alternative community-based models of service provision. Mean costs for each model of service as categorised at baseline will be compared using standard parametric tests and the robustness of the results confirmed using non-parametric bootstrapping. (3) Cost-effectiveness of models of care for child and adolescent AN - Individual level cost and outcome data will be used to calculate the relative cost-effectiveness of the alternative community-based models of service provision at the 18-month follow-up point. Cost-effectiveness will be assessed using the net benefit approach. Uncertainty around the cost and effectiveness estimates will be represented by cost-effectiveness acceptability curves. (4) Decision analysis - Data from the surveillance study will be used to populate a decision analytic model to estimate the impact on cost and cost-effectiveness of changes to the configuration of specialist NHS services and the potential for cost savings. Decision analysis is a structured way of thinking about the likely impact of a decision or policy change and involves the construction of a logical model to represent the relationship between inputs (costs) and outputs (outcomes) in order to inform resource allocation decisions under conditions of uncertainty. We will select the most suitable modelling framework in which to carry out the analysis dependent upon the results of the naturalistic study. Either a decision tree or a Markov model may be appropriate. The cost-effectiveness of the alternative service routes will be analysed using incremental analysis and probabilistic sensitivity analysis. Regression models and appropriate assumptions regarding the statistical distribution of the data will be used to explore uncertainty. The model will initially be run over 18-months in line with the data to be collected then over five-years using data from an existing 5-year follow-up study of adolescent AN (the TOuCAN study; Health Technology Assessment 2010;Vol.14:No.15).ETHICS AND OTHER APPROVALS: The study will require approval from CAPSS. Ethical approval may be required although an exemption from the National Information Governance Board for Health and Social Care (NIGB) for notification without the need for consent from children and families will be applied for given the use of anonymised data collected from clinicians. All CAPSS studies to date have been granted NIGB exemption.TIMEPLAN: Months 1 to 6 - Set-up phase to include gaining ethical R&D and CAPSS approvals and to set-up the system for CAPSS notification of eligible cases. Months 7 to 18 - Recruitment phase to involve collection of data from all clinicians providing a notification to CAPSS. Months 15 to 26 - First follow-up phase (9-months post baseline) to involve collection and costing of health service use data and collection of outcome data via telephone interviews with clinicians. Months 24 to 35 - Second follow-up phase (18-months post baseline). Months 36 to 42 - Costing data analysis and write-up.RESEARCH OUTPUTS: The primary output will be a decision analytic model capable of estimating the expected costs cost-effectiveness and cost-savings that can be generated as a result of changes to the model of service provision across the British Isles.


Research activity codes: 8.1 ORGANISATION AND DELIVERY OF SERVICES;8.2 HEALTH AND WELFARE ECONOMICS
Health categories: MENTAL HEALTH