Cognitive-behavioral Therapy for Treatment of Post-traumatic Stress Disorder and Related Problems
Condition: PTSD
MeSH terms: Stress Disorders, Traumatic; Stress Disorders, Post-Traumatic
Study type: Interventional

Summary: 
      The purpose of this study is to evaluate the efficacy of a form of cognitive behavioral
      therapy (CBT) in a population of individuals with PTSD and common related problems
      (depression, anxiety or sleep disorders, pain, psychosocial stressors, low social support,
      substance use disorder). Half of the participants will receive a cognitive behavioral therapy
      with specific modules for the treatment of related problems (CBT-E) and the other half of
      participants will receive therapy without specific modules (CBT-C).

      The main assumption is that participants treated in the CBT-E condition will present a lower
      level of symptom intensity of PTSD and a higher remission rate than those in the CBT-C
      condition during the post-treatment assessment. As a secondary objective, an analysis of the
      different parameters of effectiveness of the two forms of CBT (e.g., average number of
      sessions required to reach remission, treatment strategies used) will be performed.
    

Detailed description: 
      Post-traumatic stress disorder (PTSD) will affect nearly one in ten Canadians in their
      lifetime and more than 75% of them will develop at least one other related problem (i.e.
      depression). Results from a previous study suggest that CBT offering a flexible number of
      sessions and support for common related problems can improve the effectiveness of CBT.
      However, no studies have demonstrated the superior efficacy of flexible CBT compared to CBT
      targeting only PTSD to individuals with PTSD and common related problems.

      A randomized parallel-stratified single-blind controlled trial will be used. Randomization
      will be performed through www.randomized.net, a comprehensive internet-based randomization
      service for clinical trials, with multiple Coordinating Center users (each with their own
      role). A total of 134 individuals will be randomized to one of two therapy conditions.
      Following the initial assessment, between 8 and 32 sessions with a psychologist will be
      offered to participants upon achievement of remission of the diagnosis of PTSD.
      Discontinuation of treatment will be decided in collaboration with the participant and will
      be considered on the basis of achieving a non-clinical severity level of symptoms of PTSD on
      the PCL-5 (i.e., score <33 and absence or non-clinical level of severity of each of the
      symptoms). The participants will be re-evaluated 3 times after their therapy (1 week, 3
      months and 6 months post-therapy) on primary and secondary measures. A 1 year post-therapy
      follow-up will also be provided for the primary measure only.

      Planned analysis. The statistical analysis will respect the "intent-to-treat" principle: the
      results of all randomized participants will be included in the groups in which they were
      originally assigned. The significance level is fixed at .05 and bilateral tests will be used.
      With regards to missing data, first the type of missing data will be determined (e.g. missing
      completely randomly). Thereafter, a multiple imputation strategy (3 to 5 imputations) will be
      used to replace the data and carry out the various analysis planned. This data replacement
      strategy is recognized as being robust and efficient in addition to resolving uncertainty due
      to missing data. Generalized linear models will be used to execute group comparisons (CBT-C
      vs CBT-E) on the main measurements using the pre-treatment (T0) result as a covariate. The
      same strategy will be used for comparisons of the secondary variables and related problems.
      An analysis of the different parameters of effectiveness of the two forms of CBT (e.g.
      average number of sessions required to achieve remission, treatment strategy used) will be
      carried out.

      Subgroup analysis. No subgroup analysis is expected. Exploratory analysis will be conducted
      to determine if the results are generalizable to victims of both sexes and to the two major
      categories of traumatic exposures characterizing the sample recruited, namely violent
      criminal acts and workplace accidents.

      Sample size and calculations of treatment effects. Based on the treatment effect size
      observed in a pilot study on the effects of CBT-E, similar research, and on the use of the
      GPower power calculation software, the sample size required to obtain statistical power of
      .80 with 3 follow-ups, a significance level at .05 and bilateral testing for ANCOVA is 53
      participants per group. A sample of 106 participants will allow for detections of differences
      in means between the two groups in terms of symptoms intensity of PTSD. It will also be
      adequate to verify the other assumptions and objectives of this project. Based on data from
      our recent studies on the efficacy of CBT-C, and the literature on similar therapies (Bradley
      et al., 2005), the attrition rate is estimated to be 28% for participants who will be
      randomized in CBT-C. For CBT-E, the attrition rate observed during a pilot project was 14% (3
      dropouts out of 21 participants). Given these attrition rates, recruitment for each of the
      therapies to achieve the required statistical power is calculated as follows: CBT-C = 53
      participants * attrition (28%) = 74; CBT-E = 53 participants * attrition (14%) = 60).
      Consequently, a total of 134 participants will be randomized to one of the two conditions of
      therapy.

      Selection bias: The assignment to the intervention will be made only after the participant
      has agreed to participate in the study. Bias in statistical analysis: In order to minimize
      biases, the analysis will be carried out in a single-blind manner, the statistician will not
      know which intervention refers to the code assigned to each of them in the database. Bias
      resulting from missing data and dropouts: All analysis will follow the "intent to treat"
      principle, in order to minimize biases stemming from missing data and drop-outs during the
      intervention.

      Conducting a clinical trial on comparing the effectiveness of CBT with or without specific
      modules for patients with PTSD and related problems will increase the efficacy of CBT,
      innovate in the delivery of CBT, and improve the training of current and future clinicians.
      The results could also encourage victims' compensation boards to adjust their practices and
      thus improve the health of the beneficiaries.
    

Intervention name(s): Specific Modules; Cognitive behavioral therapy
Intervention type(s): Behavioral; Behavioral
Intervention description(s): Educational session about a specific related problem; PTSD of participants in both conditions will be addressed with cognitive-behavioral intervention strategies. These strategies are: (a) psychoeducation on PTSD, (b) anxiety management training, (c) restructuring irrational thoughts, (d) imaginative and / or in vivo exposure to memories and situations avoided, and (e) strategies for the prevention of relapse.
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Single (Outcomes Assessor)
Primary purpose: Treatment
Keywords: PTSD; Related Problems; Therapy; Traumatic Event; Quality of Life; Cognitive Behavioral Therapy (CBT); Major depression; Sleep disorders; Pain; Stressors; Social support; Substance use disorder; Anxiety disorder