Development of a scale to measure fidelity to manualized group-based cognitive behavioural interventions for people with intellectual disabilities

Research output: Contribution to journalArticle


  • Andrew Jahoda
  • Paul Willner
  • Claire Lammie
  • Jennifer Shead
  • Christopher Woodgate
  • David Gillespie
  • Julia Townson
  • David Felce
  • Aimee Stimpson
  • Nikki Rose
  • Pamela MacMahon
  • Jacqueline Nuttall
  • Kerenza Hood

Colleges, School and Institutes

External organisations

  • University of Glasgow
  • Cardiff University
  • Black Country Partnership NHS Foundation Trust
  • Directorate of Learning Disability Services Abertawe Bro Morgannwg University Health Board Bridgend UK
  • Department of Psychology, Technische Universität Dresden, 01069 Dresden, Germany.
  • Institute of Health and Wellbeing
  • College of Medical, Veterinary and Life Sciences
  • College of Human and Health Sciences
  • Swansea University
  • Abertawe Bro Morgannwg University Health Board
  • Black Country Foundation Partnership Trust
  • South East Wales Trials Unit
  • Institute of Translation Innovation, Methodology and Engagement
  • Psychological Medicine and Neurology
  • School of Medicine


The context for the present study was a cluster-randomized controlled trial of a group-based anger-management intervention, delivered by day-service staff. We aimed to develop a scale to measure the fidelity of manualized cognitive-behavioural therapy (CBT) delivered to adults with intellectual disabilities in group-based settings. A 30-item monitoring instrument (the MAnualized Group Intervention Check: MAGIC) was adapted from an existing fidelity-monitor instrument for individual CBT. Two sessions for 27 groups were observed by pairs of monitors who had no other contact with the intervention. 16 observers participated, in 15 unique pairings. Observers recorded high levels of inter-rater reliability and the scale had good internal consistency. Fidelity ratings predicted two key outcomes of the intervention, and were themselves predicted by the therapists' clinical supervisors.


Original languageEnglish
Pages (from-to)4210-4221
Number of pages12
JournalResearch in Developmental Disabilities
Issue number11
Publication statusPublished - 1 Nov 2013


  • Cognitive-behavioural therapy, Fidelity, Group, Intellectual disability, Manual