CRITICALLY APPRAISED PAPER (CAP) FOCUSED QUESTION In military veterans, what is the effect of virtual reality exposure therapy (VRE) on posttraumatic stress disorder (PTSD) and depressive symptoms, as compared with present-centered therapy (PCT)? Ready, D. J., Gerardi, R. J., Backscheider, A. G., Mascaro, N., & Rothbaum, B. O. (2010). Comparing virtual reality exposure therapy to present-centered therapy with 11 U.S. Vietnam veterans with PTSD. Cyberpsychology, Behavior, and Social Networking, 13(1), 49 54. http://dx.doi.org/10.1089/cyber.2009.0239 CLINICAL BOTTOM LINE: The estimated lifetime prevalence of posttraumatic stress disorder (PTSD) among Vietnam War veterans is 30.9% for men and 26.9% for women. Unfortunately, veterans, particularly Vietnam war veterans, with PTSD often respond poorly to interventions that are effective with other populations living with PTSD. Certain strategies even seem to exacerbate PTSD symptoms in this population. Vietnam veterans tend to avoid war-related memories, which makes many exposure therapies, especially imagined exposure therapy, difficult to conduct. Advances in computer science have allowed for the development of virtual environments, which makes it possible to give veterans easy access to war environments and allow them to stay engaged with those environments, often beyond what they would be able to accomplish in their own imagination. Evidence suggests that virtual reality exposure therapy (VRE) can reduce symptoms of PTSD in military veterans. In this study, the researchers were interested in the effects VRE would have on a Vietnam veteran population with chronic and severe PTSD. This study was a randomized controlled trial comparing the effects of VRE and PCT on PTSD symptoms in Vietnam veterans over the course of 10 sessions. Although the results of the study illustrate Clinician-Administered PTSD Scale (CAPS) score improvement in both the VRE and the PCT group, there was no significant evidence to suggest that VRE works better than PCT. This was likely due to the study s small sample size. Researchers have a difficult time recruiting and retaining participants in VRE studies. This was especially true in this study, because Vietnam veterans often avoid memories of the war and, being an older veteran group, may be cautious about the use of this kind of technology in therapy. VRE studies may have different outcomes for veterans from more recent wars, such as Operation Iraqi Freedom and Operation Enduring Freedom, because they are often younger and more open to the use of technology. Because of this, differences may be seen in the results, the recruitment, and the retention of this veteran population. More studies need to be 1
conducted on both veteran populations to fully understand the effect VRE has on PTSD. VRE has the potential to reduce the symptoms of PTSD and improve the quality of life for military veterans. This study s small sample size and subsequent lack of power, as well as its possible sampling bias, threaten its validity and effectiveness. More studies need to be conducted to truly clarify the effect VRE has on PTSD in the military population. This is especially important as more occupational therapists are using simulator or virtual environment interventions. RESEARCH OBJECTIVE(S) List study objectives. Conduct a controlled VRE study with Vietnam War veterans living with chronic and severe PTSD to determine whether VRE would produce significantly greater reductions in the symptoms of PTSD and comorbid depression, as compared with a control condition, PCT, that contained nonspecific elements of individual psychotherapy centered on the avoidance of any discussion of traumatic events DESIGN TYPE AND LEVEL OF EVIDENCE: Level I: Randomized controlled trial SAMPLE SELECTION How were subjects recruited and selected to participate? Please describe. Research staff recruited participants by making presentations to staff at the Atlanta Veterans Administration (VA) Medical Center, placing flyers in the Mental Health Clinic at the Atlanta VA, advertising on Medical Center wide VA TV, placing advertisements in local free weekly newspapers, and announcing the study in ongoing PTSD groups. These recruitment efforts elicited 96 telephone screenings. Of the 96 potential participants, 34 declined participation, and another 25 did not meet study criteria. Face-to-face assessments were done with the remaining 37 participants. Of the 37 men enrolled, 27 were assessed, and 16 did not meet study criteria, which left 11 to be accepted into the study. Nine participants completed the intervention, and 1 was lost at follow-up. Inclusion Criteria Participants were male Vietnam veterans with combat-related PTSD who were currently in treatment at the Atlanta VA Medical Center s Mental Health Clinic for at least 3 months; had a CAPS score above 60; were not taking psychotropic medications or else had been stable on them for at least 3 months; had 6 months of sobriety if they had a history of substance abuse; and had the support of their VA psychiatrist for participation. Exclusion Criteria History of or current clinical evidence of mania, schizophrenia, organic mental disorders, or psychosis; presence of prominent suicidal ideation; history of or current significant cardiac 2
problems or other physical limitations that might contraindicate exposure therapy; primary traumatic war experience that could not be simulated in the two virtual Vietnam environments used in the study SAMPLE CHARACTERISTICS N= (Number of participants taking part in the study) 11 #/ (%) Male 11 (100%) #/ (%) Female 0 (0%) Ethnicity 6 Caucasian, 5 African American Disease/disability diagnosis Male Vietnam veterans with combat-related PTSD INTERVENTION(S) AND CONTROL GROUPS Add groups if necessary Group 1: Virtual reality group Brief description of the intervention How many participants in the group? Where did the intervention take place? Who delivered? How often? Participants were exposed to one of two virtual Vietnam environments, depending on their own primary experience in the war. The two environments were a landing zone and a Huey helicopter flight ending in a hot landing zone. Intensity of stimuli could be adjusted and was increased with habituation. Auditory stimuli included yelling, jungle sounds, helicopter blades, and enemy fire in all forms (guns, explosions, land mines, etc.). Six participants were randomly assigned to this group. Conducted at the Atlanta VA Medical Center A therapist; no other information given Each session lasted 90 min. The study did not report how many sessions were conducted each week. For how long? Ten sessions were completed. Follow-up was completed at 6 months. Group 2: PCT group Brief description of the intervention How many participants in the group? Participants were given psychoeducation about PTSD and were taught problem-solving techniques. The sessions were centered around helping participants by focusing on problems that were occurring in their current life. Discussion of traumatic events was avoided. Five participants were randomly assigned to this group. 3
Where did the intervention take place? Who delivered? How often? Conducted at the Atlanta VA Medical Center A therapist; no other information given Each session lasted 90 min. The study did not report how many sessions were conducted each week. For how long? Ten sessions were completed. Follow-up was completed at 6 months. Intervention Biases: Check yes, no, or NR and explain, if needed. Contamination: Co-intervention: Timing: Site: Some participants might have been taking psychotropic medications. The study did not make clear how many participants were taking such medications. Participants did have to be stable on medications to participate in the study, but medication use in general may influence outcomes. Use of different therapists to provide intervention: NR It can be assumed that the same therapist was used, but that assumption is not conclusive. MEASURES AND OUTCOMES Complete for each measure relevant to occupational therapy: Measure 1: 4
Name/type of measure used: What outcome was measured? reliable? valid? When is the measure used? Measure 2: Name/type of measure used: What outcome was measured? reliable? valid? When is the measure used? CAPS Although the CAPS includes 30 items, this study considered only 17 core items assessing frequency and intensity of the 17 potential symptoms of PTSD. The measure was administered at baseline, posttreatment, and the 6- month follow-up. Beck Depression Inventory (BDI) 21 items assessing numerous symptoms of depression NR The measure was administered at baseline, posttreatment, and the 6- month follow-up. Measurement Biases Were the evaluators blind to treatment status? Check yes, no, or NR, and if no, explain. Recall or memory bias. Check yes, no, or NR, and if yes, explain. Others (list and explain): RESULTS List key findings based on study objectives Include statistical significance where appropriate (p < 0.05) Include effect size if reported 5
There was an improvement in symptoms, as indicated by CAPS scores, for both conditions, but extreme variability was observed, particularly in the VRE group, at posttreatment and the 6-month follow-up. No statistically significant difference between time and treatment condition was observed for CAPS scores or BDI scores, as measured by a mixed-design analysis of variance. Cohen s d effect sizes for CAPS score for the VRE group were 0.28 at posttreatment and 0.56 at follow-up. Cohen s d effect sizes for BDI score for the VRE group were 0.0 at posttreatment and 0.24 at follow-up. By combining the PCT and VRE groups for the dependent samples t tests, the authors found a significant mean improvement in CAPS score: from pre- to posttreatment, t = 2.70, and from pretreatment to follow-up, t = 2.58 (p <.05). However, there was no significant change in BDI score (p >.05). There was no statistically significant improvement in CAPS scores when individual treatment conditions were isolated; for the VRE group, t = 1.82 from pre- to posttreatment, and t = 1.78 from pretreatment to follow-up (p >.05); for the PCT group, t = 2.10 from pre- to posttreatment, and t = 2.29 for pretreatment to follow-up (p >.05). There was also no statistically significant improvement in BDI scores when individual treatment conditions were isolated (p >.05). Was this study adequately powered (large enough to show a difference)? Check yes, no, or NR, and if no, explain. The sample size was too small to show statistically significant differences between the VRE and PCT groups on the CAPS. There were only 11 participants. Were appropriate analytic methods used? Check yes, no, or NR, and if no, explain. Were statistics appropriately reported (in written or table format)? Check yes or no, and if no, explain. Was the percent/number of subjects/participants who dropped out of the study reported? Limitations: What are the overall study limitations? One of the study limitations is the small sample size. There is also possible sampling bias related to the inclusion and exclusion criteria. The researchers restricted their sample population to only include individuals who were receiving treatment at the Atlanta VA and who had a primary war 6
experience that related to the two virtual Vietnam environments that were used in the study. This might have severely limited the number of participants who could be included in the study. As such, the study population may not be representative. This might have affected the study s external validity and effectiveness. CONCLUSIONS State the authors conclusions related to the research objectives. The sample size was too small to obtain statistically significant results indicating differences between the two treatment groups. However, this study provides some support for the possible value of VRE use with veterans. The Vietnam veteran population may not be representative of the veteran population as a whole, especially veterans from more recent wars, such as Operation Iraqi Freedom and Operation Enduring Freedom. This is largely due to the considerable differences that exist between more recent conflicts and the Vietnam War. Recent wars are more complex and are often characterized by the use of technologically advanced weapons, and soldiers often go through repeated deployments. Vietnam veteran populations are also more apprehensive about technology use in therapy. As such, differences may be observed in the results, the recruitment, and the retention of veteran populations from these more recent wars. Future VRE studies with veteran populations need to focus on better ways to recruit and retain participants. This work is based on the evidence-based literature review completed by Amy Brown, OTS, and Sarah-Jeanne Salvy, PhD, Faculty Advisor, University of Southern California. CAP Worksheet adapted from Critical Review Form--Quantitative Studies. Copyright 1998, by M. Law, D. Stewart, N. Pollack, L. Letts, J. Bosch, & M. Westmorland, McMaster University. Used with permission. For personal or educational use only. All other uses require permission from AOTA. Contact: www.copyright.com 7