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Re-ASCed Research - Realist Evaluation of Autism Service Delivery

Autism is a lifelong condition, with symptoms usually emerging during the first two years of life and persisting throughout an individual’s life.

Parents often notice signs that something may not be quite right, but it might also be a teacher, doctor, or someone else. When this happens, the child and their parent see a specialised diagnosis team.

However, diagnosis of autism is not easy and parents often experience frustrating and distressing delays.

The Re-ASCed study is a national research project that aims to examine existing models of Autism diagnosis and to investigate which approaches offer the most timely, cost-effective, high quality and child and family friendly solutions.

How can services that assess children for autism make accurate and quick decisions?

Diagnosing autism is not easy. It involves gathering information about a person’s behaviour, functioning, and development by more than one type of professional. Another reason is that professionals might assess a child for other conditions too. The number of children referred for assessment has been gradually increasing over the last few years. As a result, many families spend more than a year waiting for a diagnosis.

In 2019, the NHS made a commitment for more families to get the right help, quicker. To do this, waiting times need to be shorter so children will get the right support sooner. This new national project, called Re-ASCed, aims to guide the people who plan services for autistic children and their families.

Sussex Community NHS Foundation Trust is a key partner in this study and will work with NHS England, families and parents across the UK, *** and *** over the next several years.

The first part of this research project looked for any evidence from the UK that discussed how to work out if a child or young person may have autism.

Those involved discussed the evidence with the project team, which included groups/people who support autistic people. They found there are many different approaches to diagnosis, for example, with respect to:

  • Which professional makes the diagnosis,
  • How many professionals are involved,
  • What tests are carried out.

They also found that families wanted to have their say, know what is going to happen and how long things will take. Families liked having good support and information before, during and after their child was (or was not) diagnosed. Parents liked to have a report that said what their child was good at, not just what they found difficult. They also found it helpful if the report suggested how to help their child.

Professionals wanted to have more training to understand autism. Sometimes they found it complicated to know which specialist should assess a child or young person and this caused delays. Most professionals understood that it can be upsetting for some parents to be told that their child is on the autism spectrum. Professionals also knew that often this was because local post-diagnostic support services were few and far between.

This review of the current evidence will be used as a basis for the next stages of the project:

  • A national survey of Autism Diagnostic Services to see what is currently happening in diagnostic services
  • A more detailed look at some examples of services from around England. This will include interviews and focus groups with autistic children and their families, and the professionals involved in their local autism services.

Which diagnostic pathways for children with possible autism work best, for whom, when, and at what cost?

Delays in diagnosis for children with possible autism are increasingly common, and can have a significant impact on the child, family and wider society, for example in school. Improving access to timely diagnosis has therefore been identified as a key priority for:

  • the NHS England Long Term Plan (2019)
  • by CQC and OFSTED in local areas inspection reports
  • by commissioners and clinicians in the NHS
  • within the Autistica James Lind Alliance Research Priority Setting
  • by charities, including the Embracing Complexity Alliance, and
  • by parents.

This study seeks to address the desire, expressed in the NHS England Long Term Plan, to “test and implement the most effective ways to reduce waiting times and achieve timely diagnostic assessments in line with best practice guidelines”. It will do so by examining existing examples of innovative practice.

In the UK, NICE guidelines recommend that diagnosis should be made by specialist multidisciplinary teams with the skills and training to be able to identify if the child has autism; but, also to recognise other conditions that present similarly, or that can occur alongside autism, such as ADHD. The team may include paediatricians, child psychiatrists, speech therapists, psychologists and others.

The assessment process is labour intensive and costly, our own research suggesting this typically takes 13-14 hours, costing £8-900/child. Given that the number of children being diagnosed has doubled in recent years, with often limited additional resources available to meet the resulting increase in demand for diagnostic assessment, waiting times have increased significantly. Our recent survey suggesting that families often wait one to two years, or longer, for a diagnosis, even once they have been referred for assessment, which itself can take several years.

Set against this background the aim of this project is to identify approaches that deliver a high quality and timely diagnostic assessment.

To do this, the team are conducting a literature review and a survey of current UK practice in child development services (CDS) and child and adolescent mental health services (CAMHS) to find out what approaches are in place that may help.

Six to eight services from the survey will be selected to observe in detail. This will enable the team to understand how their approaches have been successful, and what needs to be in place for this to happen. For example, it may be that an approach such as running an integrated CAMHS/CDS neurodevelopmental pathway that has worked well in a city setting, with both teams working in the same building and health trust, may not work so well in a large rural county with 3 or 4 health trusts involved and with CAMHS and CDS based in different locations.

The six or eight teams will be selected for their use of different and innovative approaches which have enabled them to improve timeliness and quality of assessment. Where possible, two teams will be examined for each approach.

The different approaches will be studied to find out what works well in each team, what helps this and what things can make this difficult. This will help the team to understand whether similar approaches could work as well elsewhere, for example, what professional backgrounds (eg nurse or psychologist), training and support need to be in place to enable successful introduction of skill mix solutions.

Interviews will take place with clinical staff, managers, referrers, parents and young people to understand how the service works, and how those who have used the service feel about their experiences. Parents and young people spoken to will have all experienced the diagnostic process.

Information from case records will also be studied, including:

  • dates of referral and each clinical contact
  • members of the team involved and time taken in each assessment, and
  • diagnostic outcome,

to examine the journeys of 70 children going through the diagnostic process in each type of service.

This will help determine how long each assessment takes, how much clinician time it takes, and how much it costs. The findings will be compared across teams and approaches. The study is using an approach known as Realist Evaluation which is designed to look at services to ask the question: ‘what works, for whom, in what circumstances, over what duration and why?’. We have added a further question: At what cost?

The research team has specialist expertise in autism, health service (including Realist Evaluation) and health economics research, and statistics, and of delivering autism diagnostic services within the NHS, in CDS, CAMHS and tertiary settings. The team includes public and NHS England partners who have, and will continue to, contribute to the co-design and co-delivery of the study. This will ensure we take account of the needs of families.

Once data has been analysed, national meetings with autism experts and patient groups will be held to discuss the findings.

These groups will agree recommendations for practice, which will be shared with clinical teams, service managers, commissioners, parents’ groups, and NHS England.

Scientific Summary (following Rameses 2 reporting guidelines)

Study Title

A Realist Evaluation of Autism ServiCe Delivery (RE-ASCeD): Which diagnostic pathways work best, for whom, when, and at what cost?

Research Question

Which autism diagnostic pathways work best, for whom, in what circumstances, and at what cost when providing timely and high-quality diagnostic services?

“Timely” currently refers to diagnostic pathways that according to NICE41 guidelines must be started within three months of referral, but does not give an end point for the process. Timely for this project is defined as: “A pathway lasting no more than one calendar year (365 days). Pathways need to be started within three to four months of referral (18-week rule), with assessment taking no longer than six to nine months.” We recognise that waiting times may be affected by the Covid-19 Pandemic and Lockdown, as many services have either had staff redeployed to support acute services and/or to pause autism diagnostic clinics as face to face observation/assessment (e.g. use of ADOS) of the child has not been possible

“High Quality” is defined by compliance with NICE guidelines41 and quality standard on Autism. This is when an assessment is conducted by a multi-disciplinary team (MDT), with competencies in child neurodevelopment and/or mental health, and includes

  • Detailed questions of parents concerns
  • Childs experience of home life, school, social care etc
  • Developmental history with focus on ASD criteria (consider standard tool e.g. ADI)
  • Assessment by interaction and observation of social skills, sensory and repetitive behaviours etc
  • Medical history and physical examination
  • Consideration of differential diagnosis
  • Systematic assessment for conditions that may coexist with ASD
  • Development of a profile of child’s strengths, skills, impairments including intellectual ability, speech, motor, sensory and adaptive behaviours (e.g. sleep, eating), and mental and neurodevelopmental health
  • Assessment for co-existing physical and mental health problems including genetic, cerebral palsy, epilepsy

As has been defined by our “Initial Program Theory” (see below).

In keeping with the iterative nature of realist evaluation, we anticipate these definitions may well change over the course of the study, not least with the potential impact on waiting times for outpatient-based services, of the “Coronavirus lockdown”.

Secondary Research Questions

  • What factors underpin timely diagnosis service delivery success or failure?
  • What needs to be in place to identify the needs and create individualized, holistic pathways of diagnosis for the child and their family?


The NHS England Long Term Plan states: “Children and young people with suspected autism wait too long before being provided with a diagnostic assessment. Over the next three years...(we aim) to test and implement the most effective ways to reduce waiting times…achieving timely diagnostic assessments in line with best practice guidelines...(and) to support children with autism and their families, throughout the diagnostic process.” Set against a background of increasing demand for diagnostic assessment, and the need, as recommended by the NICE guidelines, for a multidisciplinary approach to assessment, taking an average 13 hours of professional time and £800 per child, evidence is needed to identify models of diagnostic assessment to achieve timely diagnoses, and how families can best be supported through this process. The NHSE Long Term Plan aims to reduce the wait time for diagnosis, and the aim of this project is to find ways/models to directly address that need.


Aims and Objectives

This study aims to examine existing models of Autism diagnostic service delivery, and to investigate which approaches offer the most timely, cost-effective, high quality and child and family friendly solutions, and in line with realist thinking, to identify the factors that are likely to underpin their success, or failure, if rolled out more generally across providers.


Method for Overall Study (ie Work Packages 1 to 5)

The study will use Realist Evaluation methodology, which enables evaluation of complex interventions in health care by building on existing research, to identify “what works, for whom and in what circumstances”. Mixed methods, including Rapid Realist (literature) Review (currently underway), survey of current practice (about to commence), and case studies of centres delivering promising approaches, will be used to build a picture in an iterative manner, to identify underlying Contexts and Mechanisms that contribute to the desired Outcomes (CMO configurations) of improved Autism diagnostic service delivery and user experience, that in turn can provide plausible explanations of why the service models work or do not in certain circumstances (Shearn et al, 2017). Data analysis from each phase of the study will be synthesised through a realist evaluative process comprising of five stages (Hewitt et al,2012):

  1. Articulation of programme theories and propositions from WP1 of the study (rapid realist review). Identification of candidate CMO configurations. (in write up phase (22/5/20)
  2. Online survey to create a national picture of current diagnostic practice across paediatric and child mental health services, and identify potential study sites for WP4, who have already introduced approaches to improve the timeliness and quality of their Autism diagnostic, and support, services. (HRA approval NIHR Portfolio status confirmed, survey launched 1/6/20)
  3. WP3 will use results from the above to create a typology, and sampling frame and identify and recruit sites to act as case studies in WP4.
  4. Data collection from WP4 (case studies) of the study to test and refine propositions.
  5. Map the outcomes of each model across the cases; interrogate what contexts and mechanisms explain the pattern of outcomes.
  6. Through stakeholder consolidation (WP5), refine explanatory CMO configurations to evaluate what works best and in what circumstances to deliver timely, and high quality, diagnostic services that meet the needs of children with possible autism, and at what cost.


Initial Programme Theory (Based on NICE principles)

If there is an MDT assessment by a team with competencies in child neurodevelopment and mental health (context), then Autism will be recognised as a complex condition that relies on detailed history and observation across settings (mechanism) to diagnose it, leading to an accurate diagnosis, recognition of associated comorbidity such as ADHD and intellectual disability (outcome), and the ruling out of complex differential diagnoses.

This will also create accurate pictures of child strengths and needs to inform individualized packages of support and intervention through health, education and social care (outcome).

Work Package One (months 1-7). Rapid Realist Review83.

We have now completed this literature review from published studies and evaluations of autism diagnostic services, including controlled trials, uncontrolled studies, cost-effectiveness studies, process evaluations, grey literature and qualitative studies, including unpublished information about locally implemented Autism services has now been completed. This has enabled development and refinement of our initial programme theory, into 7 areas, as follows (subject to review with expert stakeholder group):

  • Programme theory 1 – Recognition: Frontline health and education professionals (e.g. GPs, teachers) are confident in recognising the signs and symptoms of autism, are cognisant of referral pathways and take parents/carers’ concerns seriously
  • Programme theory 2 – Referral: If autism diagnostic services provide clear guidelines for referrers on what information is needed and how to refer, then time will be saved at the triaging stage and fewer children who do not have ASD will go through the full process.
  • Programme theory 3 – Diagnostic model: There is wide variation in the model for ASD diagnostic services (e.g. autism only, all Neurodevelopmental Conditions, integrated CDC/CAMHS) and national staff shortages but these can be addressed with a structured and consistent approach, making best use of available staff and clinical expertise.
  • Programme theory 4 - Diagnosis & support: If parents understand the diagnostic process and feel supported this can moderate parental expectations. Feedback should take an assets-based approach and the management plan should be individualised, taking account of co-existing conditions. Reports should be timely, and in a format that everyone finds helpful.
  • Programme theory 5 - Working in partnership with families: Parents find the diagnostic pathway stressful so find it helpful to have a single point of contact, explanations about the process and being included in decision making.
  • Programme theory 6 - Inter-agency working: If “experts” including people with autism, carers, professionals and specialist organisations work in partnership and knowledge built in the autism sector is effectively embedded into local services this will build capacity, improve parent/child satisfaction and support local planning of services both nationally and locally.
  • Programme theory 7 – Training, service development and evaluation: Based on their needs, skills and knowledge for autism diagnostic assessments and working with families, health and community professionals should have access to tailored training, service development and service evaluation

Work Package Two (delayed by Covid/ethics processes, to launch 1/6/20): National Survey of Current Diagnostic Practice: An electronic survey of UK CDCs, CAMHS teams, and tertiary centres, delivering Autism diagnostic services is underway. This ask teams to describe current challenges to, and any new models of diagnostic service delivery they are using. Analysis will use both qualitative and quantitative methods, to identify common themes, and services using novel approaches.

Work Package Three (months 7-9): Purposive Sampling Frame. The findings of WP 1 & 2 will be used to develop a matrix of the key features of service delivery, plus other contextual factors such as lower SES, rural, urban etc. This will be used as a sampling frame. It is anticipated that 6-8 service delivery models will be purposefully selected as case studies across the matrix to ensure we have a full range of delivery models and population characteristics.

Work Package Four (subject of this ethics application): Case studies (months 10-29): In-depth exploration of individual service models will be carried out to determine the interrelationship of context, intervention, mechanisms and outcomes as they occur in their natural setting. Data will be gathered within case studies using mixed methods at two levels: (i) service model and (ii) individual child/ family. Methods will include semi structured realist interviews, focus groups, and document reviews to assemble a comprehensive description of the service and model. Interviewees will include commissioners, service managers, clinicians, referrers, parents and young people. In light of the Covid-19 Lockdown, where possible, and acceptable for the interviewee, interviews, will be carried out using video conferencing. Interviews will be recorded and transcribed, proceeding to qualitative analysis based on components of the programme theory. Regular team meetings will discuss coding, address inconsistencies, and refine collective understanding of coding framework. Coded data will be collated using NVivo software.

For each service type studied, the journeys of at least 70 children (i.e. 35 per case study site) completing the diagnostic pathway will be recorded from case notes to measure the pathway, hours of professional input and time to diagnosis. Costs incurred by families for example travel to clinic, loss of earnings, will be collected by telephone questionnaire, and within focus groups. Associations between service use costs and characteristics of the child and model will be assessed by regression analysis.

Work Package Five: Consolidation event, Months 27-28: We will run two iterative national consensus workshops, inviting key stakeholders including NHSE, service commissioners and providers, and parents/young people, to refine and confirm the context-mechanism-outcome configurations, and salient actions required to deliver timely, reliable and costed diagnostic services that meet the needs of children with possible Autism. This will lead to dissemination of models to inform the ongoing development of service models within the NHSE Long-Term Plan, commissioning guidelines and local service development.

The Re-ASCed Team

Chief Investigator

Dr Ian Male, Consultant Community Paediatrician, Sussex Community NHS Trust, Honorary Senior Lecturer Brighton and Sussex Medical School. Clinical expertise in autism diagnosis, research includes “cost of autism diagnostic assessment” and use of digital technologies in therapy and diagnosis for children with neurodisability. https://scholar.google.co.uk/citations?user=riTEFowAAAAJ&hl=en

Co-Chief Investigator:

  • Dr William Farr, Senior Research Fellow in Paediatric Neurodisability SCFT, Honorary Lecturer BSMS. Co-Chief Investigator, Experience as school deputy head/SENCO referring into autism diagnostic services. Research includes “costs of autism” and potential digital aids to diagnosis. Co-leading PPI https://scholar.google.co.uk/citations?user=lIqSxAsAAAAJ


  • Professor Patricia Wilson, Professor of Primary and Community Care, Kent Academic Primary Care Unit, University of Kent, Canterbury. Expertise in Realist Evaluation, qualitative research. Mentor to Dr Male https://www.kent.ac.uk/chss/staff/research/wilson.html
  • Professor Jeremy Parr, Professor of Paediatric Neurodisability, Newcastle University, and Honorary Consultant Paediatric Neurodisability, Northumberland Tyne and Wear NHS Trust. Clinical expertise in autism and co-existing diagnosis and management at Tertiary level. Research expertise in autism, including diagnosis and intervention studies https://www.ncl.ac.uk/medical-sciences/people/profile/jeremyparr.html
  • . Professor Heather Gage, Professor of Health Economics, University of Surrey, Guildford. Director of Surrey Health Economics Centre. Expertise in health economics and health services research https://www.surrey.ac.uk/people/heather-gage
  • Peter Williams, Statistician, University of Surrey. Statistician https://www.surrey.ac.uk/people/peter-williams
  • Dr Venkat Reddy, Consultant Neurodevelopmental Paediatrician and Clinical Director, NHS Trust. Previous BACCH Convenor. MBBS, MRCP (UK), FRCPCH. Expertise in quality improvement including as national QI Lead, RCPCH Service Review Team, leads and developed integrated CAMHS/CDC service https://uk.linkedin.com/in/dr-venkat-reddy-a8b6ab23
  • Dr Victoria Grahame, Consultant Clinical Psychologist, Northumberland Tyne and Wear NHS Trust. Clinical lead, Complex Neurodevelopmental Disorders Service. Honorary Clinical Senior Lecturer, Newcastle University. Clinical expertise in autism and co-existing diagnosis and management at Tertiary level. Research expertise in autism, including intervention studies


  • Dr Gráinne Saunders, Trustee & Health Representative for West Sussex Parent Carer Forum, PPI Partner. Active in CYP Sussex TCP working group as well as (CDC) national Expert Parent Programme trainer which supports parent carers to work better with health professionals. WSPCF has strong links to SE19 PCFs and National Network Parent Carer Forums for PPI


  • Amanda Allard, Assistant Director, Council for Disabled Children. Researcher and campaigner in children’s policy including issues of family support and child disability, including working with an autism charity. Working with young people contributing to PPI.


  • Dr Lorcan Kenny, Discover Lead, Autistica. Leads the Discover network for Autistica, the UK’s national autism research charity. Discover, is the UK’s national autism research network which is making it easier for the autism and research communities to work together.



Text so far:

  1. A Realist Evaluation of Autism ServiCe Delivery (RE-ASCeD): Which diagnostic pathways work best, for whom and in what context? Protocol for a rapid realist review

V Abrahamson, W Zhang, PM Wilson, W Farr, I Male

BMJ Open (2020)

  1. Should clinical services for children with possible ADHD, autism or related conditions be delivered in an integrated neurodevelopmental pathway?

I Male, W Farr, V Reddy

Integrated Healthcare Journal 2 (1), e000037 (2020)

  1. How much does it cost to assess a child for possible Autism Spectrum Disorder in the UK National Health Service: An Observational Study

I Male, W Farr

Proceedings of the 31st annual meeting of the European Academy of Childhood Disability (2019)

  1. Cost of assessing a child for possible autism spectrum disorder? An observational study of current practice in child development centres in the UK

M Galliver, E Gowling, W Farr, A Gain, I Male

BMJ paediatrics open 1 (2017)


How to get involved

If you are a parent and would like to get involved in this research study, please find details below about how to make contact;

For case studies please contact:

In the South of England:
Dr Will Farr - Senior Research Fellow in Paediatric Neurodisability
Research and Innovation Department
Sussex Community NHS Foundation Trust
Bramber Building
Brighton General Hospital
Elm Grove
E: will.farr@nhs.net

Or in the North of England:
Professor Jeremy Parr –
Development & Disability Group, Newcastle University
3rd Floor, Sir James Spence Institute
Royal Victoria Infirmary
Queen Victoria Road
Tel: +44 (0)191 282 5965

Contacts and if you want to take part –

Dr Ian Male - Consultant Community Paediatrician
Dr Will Farr - Senior Research Fellow in Paediatric Neurodisability
Research and Innovation Department
Sussex Community NHS Foundation Trust
Bramber Building
Brighton General Hospital
Elm Grove
E: ian.male@nhs.net; will.farr@nhs.net