The need for careful study design when investigating the benefits of psychological interventions for trauma survivors: A commentary on Renner, Banninger-Huber, Peltzer (2011)

Methodological concerns are explored and questions raised about the validity of conclusions reached in a recent article by Renner, Bänninger-Huber and Peltzer (2011). These authors reported treatment outcomes of Chechen asylum seekers and refugees with Posttraumatic Stress Disorder (PTSD), anxiety and depression following treatment with Group Cognitive Behavioural Therapy (CBT); a Culture-Sensitive and Resource Oriented Peer Group (CROP); Eye Movement Desensitization and Reprocessing (EMDR); and a wait-list condition. They concluded that CROP was significantly superior to wait-list and as effective as CBT in reducing symptomatology, and that EMDR was ineffective. However the study contains serious methodological problems including a lack of randomization information, a lack of independent evaluators, inadequate treatment fidelity, and inadequate treatment dosage. Furthermore, the small sample size, high attrition rate and unequal group numbers compromise the statistical power of this study, and possibly compromise the underlying statistical assumptions rendering any conclusions unreliable. This is serious given that misrepresentation of data is damaging to treatment models and clinical practice where such articles guide clinician's treatment choices.