Trauma-informed practice
: Principles and attrition

  • Sinead Mitchell

Student thesis: Doctoral ThesisDoctor of Philosophy


(1) Effects of baseline psychological symptom severity on dropout from trauma-focused cognitive behavior therapy for posttraumatic stress disorder: A meta-analysis
A meta-analysis was conducted to explore the impact of baseline psychological symptom severity on treatment dropout among adults administered Trauma-Focused Cognitive Behavior Therapy (TF-CBT) for Posttraumatic Stress Disorder (PTSD). Literature on how baseline psychological symptom severity influences attrition has produced inconsistent findings. No review to date has analyzed outcomes across studies. This meta-analysis compared baseline severity scores of, a) clinician-rated PTSD symptoms, b) self-report PTSD symptoms, and c) comorbid psychological symptoms, between TF-CBT completers and dropouts. Eligible studies were peer-reviewed, original outcome research of TF-CBT trials with adults meeting diagnostic criteria for PTSD. Data included standardized and quantitative baseline scores of clinician-rated and/or self-report PTSD and comorbid psychological symptom severity for treatment completers and dropouts. Searches were conducted of PsycINFO, Web of Science and SCOPUS and resulted in the identification of 12 studies with data received for 881 adult participants with a primary diagnosis of PTSD. Nine Randomized Control Trials (RCTs) and three non-RCTs were included. The interventions in the studies were guideline-recommended and evidence-based treatments of Prolonged Exposure, Cognitive Processing Therapy and Cognitive Behavioral Therapy for PTSD. Findings revealed participants dropping out of treatment had higher clinician-rated PTSD symptom severity at baseline than those who completed, with a significant and moderate effect size observed (g = -.50, 95% CI [-0.95, -0.04], p < .05). No other findings were significant. The implications of inconsistent definitions of treatment dropout in included studies are discussed.
(2) Reaching consensus on the principles of trauma-informed care in early intervention psychosis services: A Delphi study

Aim: The current study sought to conceptualise and reach consensus on the principles of trauma-informed care in early intervention psychosis services.

Methods: A three-phase Delphi method was employed in this study.Experts included researchers, service providers and Experts by Experience in the area of early intervention in psychosis. In the initial qualitative phase,an expert panel (n = 57) shared their views on the constituents of trauma-informed care in early intervention psychosis services. Thematic analysis led to the generation of statement items. The expert panel were asked to rate the extent to which each statement item was an essential principle of trauma-informed care, leading to consensus of endorsed principles.

Results: Qualitative analysis of the first phase data led to the identification of 185 distinct statements which were compiled into an online questionnaire for the panel to rate in Phase 2. The Phase 2 questionnaire was completed by 42 experts, with the endorsement of seven principles. In Phase 3 the panel were invited to re-rate 24 statements. This phase was completed by 39 panel members, with the acceptance of a further nine principles. Consensus was achieved resulting in the endorsement of 16 essential principles of trauma-informed care.

Conclusions: The study offers novel understanding of the conceptualisation of trauma informed care in early intervention services and suggests principles which are widely agreed by experts in the field. There commendations may inform the adoption of consistently delivered trauma-informed care in early interventions in psychosis and facilitate the evaluation and development of services.

Date of AwardDec 2020
Original languageEnglish
Awarding Institution
  • Queen's University Belfast
SupervisorDonncha Hanna (Supervisor) & Ciaran Mulholland (Supervisor)


  • CBT
  • dropout
  • posttraumatic stress disorder
  • symptom severity
  • Delphi technique
  • early intervention
  • psychosis
  • trauma-informed

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