Authors' objectives: Interventions for anxiety need to be adapted to meet the needs of autistic people with moderate to severe learning disabilities and successfully modelled before evidence about efficacy can be generated from clinical trials. The objectives were to: (1) adapt a behavioural intervention for anxiety, develop an intervention fidelity checklist and logic model, and appraise candidate outcome measures, together with carers, autistic people, and clinicians, (2) characterise treatment-as-usual, (3) model the adapted intervention to determine the acceptability and feasibility for all stakeholders, judge the appropriateness of outcome measures, examine the feasibility and acceptability of consent and associated processes and (4) describe factors that facilitate or challenge intervention delivery. A large number of people with autism and learning disabilities have problems with anxiety. There is evidence that talking psychological therapies are an effective intervention for anxiety, but many of these interventions have not been tested with people who have both autism and learning disabilities. These interventions need to be adapted before they can be used with this population because of their difficulties with verbal communication, restricted and repetitive behaviours, and behaviours that challenge. We aimed to (1) work with our patient and public involvement (PPI) partners to adapt an existing intervention manual for anxiety disorders for use with autistic adults with moderate to severe learning disabilities and (2) complete a feasibility study to try out our intervention and seek feedback from participants, families and therapists. In addition, we collected information about what interventions people are currently receiving to characterise treatment-as-usual (TAU) and test out some outcome measures. Phase 1a: adaptation Our objectives were: to establish an intervention adaptation group (IAG) and, during a series of meetings, adapt an existing intervention to treat anxiety symptoms in autistic adults who have moderate to severe learning disabilities to develop an intervention fidelity checklist that can be used alongside the intervention manual to appraise and consider several candidate outcome measures of anxiety-related symptoms and make a recommendation for use within Phase 2 to develop an intervention logic model.

Authors' results and conclusions: The intervention was successfully adapted and modelled with 28 autistic participants with moderate to severe learning disabilities. The intervention was judged to be feasible and acceptable by autistic adults with learning disabilities, carers, and therapists. Carers and therapists suggested minor intervention revisions. Carers completed 100% of outcome measures and the missing data rate was low; however, they indicated that some of the questions were repetitive and said they had difficulty responding to some items. The use of the Mental Capacity Act, 2005, led to an average 5-week delay to participant enrolment. The accrual rate was affected by the COVID-19 pandemic and improved during the summer and early autumn of 2022. The BEAMS-ID intervention and associated study processes were judged to be feasible and acceptable. The intervention required minor revision. Phase 1a We successfully adapted the intervention, developed a logic model and intervention fidelity checklist, and chose outcome measures collaboratively with the IAG. The BEAMS-ID intervention was judged to be feasible to deliver and acceptable to autistic adults with moderate to severe learning disabilities, carers and therapists. Carers and therapists made some helpful suggestions for revisions which can be easily incorporated into the existing manualised intervention with minor revision. This study took place during the COVID-19 pandemic and the recruitment of participants during Phase 2 was at a lower rate than anticipated, considering that the study was funded prior to the onset of the pandemic. Nevertheless, 93% of the planned sample size was successfully recruited, and it was noted that the accrual rate improved during the summer of 2022 and was higher within sites who joined towards the end of the study period. The participant attrition rate was low and not attributable to the intervention or study processes. This study benefited from genuine patient and public involvement and engagement during the adaptation of the intervention, development of fidelity checklist and logic model, choice of outcome measures and study management. Following minor revisions to the intervention, and further consideration of outcome measures based upon carer feedback, the BEAMS-ID intervention should be tested in a randomised trial.

Authors' methods: This study had two phases. Phase 1a: using consensus methods, an intervention adaptation group was formed who met to adapt the intervention, appraise candidate outcome measures, and contribute to the development of the intervention fidelity checklists and logic model. Phase 1b: a national online survey was conducted with professionals to characterise treatment-as-usual. Phase 2: this was a single-group non-randomised feasibility study designed to model the intervention to test intervention feasibility and acceptability, outcome measures, and aspects of the research process. Participants were recruited from National Health Service community adult learning disabilities teams in England. Participants aged 16 and over with a diagnosis of autism, moderate to severe learning disabilities, an anxiety disorder, and a carer who was available to take part in the intervention. For those who lacked capacity to make a decision about taking part, a consultee had to provide advice that the participant should be included in the study. The intervention comprised 12 sessions alongside treatment-as-usual. The feasibility and acceptability of the intervention and research processes, outcome measure completion rates, and intervention adherence. Randomisation was not modelled within this feasibility study, although carers and therapists indicated that this would be acceptable. Study design Phase 1a (intervention adaptation) An IAG was established, and during a series of five meetings an existing intervention used to treat anxiety symptoms in adults with autism was adapted for use with people who also have moderate to severe learning disabilities. Phase 1a (intervention adaptation) The IAG included eight key stakeholders who were representatives from our PPI partners, carers and family members, people with autism and/or learning disabilities, and clinicians, along with members of the research team.

Project Status: Completed

URL for project: https://www.journalslibrary.nihr.ac.uk/programmes/hta/NIHR129804

Year Published: 2024

URL for published report: https://www.journalslibrary.nihr.ac.uk/hta/MWTQ5721

URL for additional information: English

English language abstract: An English language summary is available

Publication Type: Full HTA

Country: England, United Kingdom

DOI: 10.3310/MWTQ5721

Organisation Name: NIHR Health Technology Assessment programme

Contact Address: NIHR Journals Library, National Institute for Health and Care Research, Evaluation, Trials and Studies Coordinating Centre, Alpha House, University of Southampton Science Park, Southampton SO16 7NS, UK

Contact Name: journals.library@nihr.ac.uk

Contact Email: journals.library@nihr.ac.uk