Critical Incident Stress Debriefings for
Cross-Cultural Workers: Harmful or Helpful?
by
Karen F. Carr, Ph.D., 2003
Mobile Member Care Team
Accra, Ghana
What is Critical Incident Stress Debriefing (CISD)?
Most commonly this term is associated with the Mitchell model (Mitchell, 1983). This is a formal, structured process led by trained facilitators (not exclusively mental health professionals) that occurs soon after a potentially traumatizing event and involves telling the traumatic story, sharing emotions, and the teaching of common reactions of trauma and coaching in coping skills. The purpose of CISD is "to prevent unnecessary aftereffects, accelerate normal recovery, stimulate group cohesion, normalize reactions, stimulate emotional ventilation, and promote a cognitive grip on the situation" (Dyregrov, 1997). It is not therapy. It is one method of crisis support that is intended to be part of a more comprehensive critical incident stress management program. This model allows for peer debriefing programs such that a fire fighter might help to debrief his fellow fire fighters, for example. With specialized training, peer helpers can provide immediate, on site care and make referrals to mental health professionals when there are signs of pathological responses to trauma.
The Mobile Member Care Team is an interdisciplinary non-profit organization providing crisis response and training to missionaries and humanitarian aid workers in West Africa . We provide direct crisis care as well as providing peer crisis response training. We are in a setting where there is a high incidence of crises and trauma (i.e., war, evacuation, civil unrest, serious medical illness, armed robberies) and very few resources for psychological care. In the past when there was no on site counseling care available, many missionaries left the field prematurely. In the 14 countries in West Africa where we work, there are over 10,000 missionaries and cross-cultural church workers. Our team of three full time staff is not able to respond directly to the needs of all these individuals and families. Therefore, we have a strategy of training and equipping leaders and peers to provide more informed, compassionate care to their colleagues and friends in the aftermath of crises. We provide ongoing supervision and consultation for the peer responders we train. In our context of working with missionaries in West Africa, we have modified the Mitchell CISD model to include additional aspects of talking about the spiritual aspects and meaning of the event, mobilizing support networks, addressing and working through cognitive distortions using affirmation and reframe, and making plans for the future.
The criticism of Critical Incident Stress Debriefings
"The results of (research) indicate that one-time psychological debriefing for individual following traumatic events does not prevent the development of later psychological (problems), but it is a well-received intervention for most people. It would be premature to conclude that psychological debriefing should be discontinued as a possible intervention following trauma, but there is an urgent need for (good research) ." (Bisson, et. al., 2000)
"Although psychological debriefing represents the most common form of early intervention for recently traumatized people, there is little evidence supporting its continued use with individuals who experience severe trauma..It appears that there is sufficient evidence to recommend that psychological debriefing not be provided to individuals immediately after trauma.. There is consensus, however, that providing comfort, information, support, and meeting people's immediate practical and emotional needs play useful roles in one's immediate coping with a highly stressful event ." (Litz, et.al., 2002)
"There is no current evidence that psychological debriefing is a useful treatment for the prevention of post traumatic stress disorder after traumatic incidents. Compulsory debriefing of victims of trauma should cease." (Rose, et al., 2003)
These are strong words spoken by respected psychologists and they cannot be ignored. But, what are the implications for the provision of effective crisis intervention by mission leaders and missionary peers on the mission field when most of the time professionals are not available? Let's take a closer look at what the research has shown and then I'll draw some conclusions and make some recommendations.
In some ways it could be easy to dismiss these conclusions as being too strong or too premature. That's because there actually hasn't been a lot of research done on debriefing and everyone agrees that more research is needed and the research that has been done has often been methodologically flawed. These flaws include debriefings being too short (20-60 minutes), debriefers being inadequately trained or experienced, and debriefings occurring too soon (Wessely, et.al., 2000). Inconsistencies have been found across the studies in method, trauma type, and recipients. Also, few of the studies include appropriate control groups.
Mitchell and Everly have rebutted these criticisms citing research that has demonstrated positive effects of CISD. Everly and Boyle (2001) conducted a meta-analysis of five previously published studies and demonstrated a large effect size, supporting the argument that the CISD model is an effective tool of crisis intervention and mitigates symptoms of psychological distress. Jenkins (1996) found in a study that CISD was useful in reducing symptoms of acute depression and anxiety after a mass shooting. Wee (1995) found that emergency workers who participated in CISD following a civil disturbance had more rapid reductions in posttraumatic stress symptoms. Leeman-Conley (1990) described the development of a CISM program in a large banking system which included precrisis training, group debriefings following crises, and professional counseling when needed. They found that after the implementation of this program, sick leave was reduced by 60 percent and workers compensation claims were reduced by 68 percent. This has clear implications for mission organizations operating in high stress, high crisis areas.
Nevertheless, there have been some troubling themes in studies that have been done which conclude that CISD is not helpful and in some cases is harmful. In most of these studies, a group of people has been through a similar kind of trauma (e.g., a motor vehicle accident or a severe burn). Some are offered debriefing and others are not. Over time, they are assessed for their post-trauma symptoms, particularly things like post-traumatic stress disorder, depression, or other pathological symptoms. This research has found that the people who received debriefing have not had fewer post-traumatic stress disorder symptoms and in some instances they have had more symptoms than the ones who were not debriefed. This has led to the conclusion that debriefing is not effective and may be harmful in some situations. Unfortunately the studies have not identified what elements of debriefing might actually be harmful or why some people end up with exacerbated symptoms and others do not. It also is not always clear how improvement is being assessed. Do we define improvement as a lack of anxiety, depression, or post-traumatic stress disorder symptoms? Over what period of time are these symptoms the same or worse than those who have not experienced debriefing? As a temporary state, are some of these symptoms in fact an indication of increased awareness and distress that may motivate them to greater health at a future point? It does not appear that other indices of successful trauma recovery such as quality of support system, spiritual growth and development, increased sense of meaning and purpose in life, or improved coping mechanisms have ever been assessed in connection with the benefits of a debriefing or other forms of crisis intervention following a traumatic incident. If debriefing is not effective or even harmful, why does it seem that a high percentage of those receiving it give a self-report that it was helpful? What are they referring to?
It seems that what can be definitively and strongly said is that the research done so far has not convincingly demonstrated that critical incident stress debriefings are useful in preventing post-traumatic stress disorder or other pathological reactions to trauma. A question that remains unanswered is whether or not debriefing has beneficial effects that to date have not been measured. For example, is it possible that those who are debriefed on the mission field following traumatic experiences are less likely to leave the field prematurely than those who are not debriefed? In one study (Lovell, 1999), 33 missionaries received a debriefing after returning from an overseas assignment. Eighty-two percent of these participants reported that they found the debriefing helpful or very helpful. The remaining participants described it as unnecessary but did not describe it as negative. More objectively, the Impact of Events Scale (Horowitz, et. al.) scores showed significant differences between this group of missionaries who was debriefed as compared to 145 other missionaries who were not debriefed. The debriefed group showed a significantly lower level of unpleasant intrusive memories and lower levels of avoidance.
As more research is done, these things will become clearer. In the meantime, we have an ethical responsibility to make sure that we minimize the risk of any harm being done in the psychological debriefings offered.
What might cause CISD to be harmful?
• Lack of choice — In the past, some have recommended that organizations consider making CISD mandatory following a trauma (Carr, 1993). The rationale behind this was that it was a helpful process that a person might not choose due to the stigma of "needing" help following a crisis. Particularly for some populations that have reputations of being "tough" like police officer, fire fighters, and missionaries, there was a kind of face saving value in being told to go to a debriefing rather than admitting that you felt you needed one. I have seen organizations where CISD was required and the person initially resisted this requirement but afterwards was very glad they had received it. I have also seen organizations where CISD was voluntary, the person did not choose it and then later expressed great regret that they had not been urged to do so. On the other hand, if a person feels forced to talk about something that they are not ready to talk about, this can be harmful and detrimental to them. And given that the evidence has not proven that CISD is a beneficial thing, it does make sense that this intervention should be a person's choice rather than a medicine that is given to them because it's good for them whether they like it or not. The issue of declining the intervention and then later regretting it might be resolved by improving the process of educating people about what CISD is and is not and giving them multiple opportunities over a period of time. It will also be helpful if administrators and leaders are well informed as to the nature and potential benefits of CISD. Policy could be worded such that it is understood that debriefings are standard procedure rather than coercive language such as "required" or "mandatory." This encourages and supports even the reluctant workers to attend a debriefing, while not forcing the issue for those who genuinely feel it is not in their best interests to attend.
• Poor timing — The Mitchell model of CISD has called for interventions to be offered between 48-72 hours after the trauma. While this may be ideal timing for some, for others it may be too soon. Factors such as fatigue, being overwhelmed, still having multiple logistical issues to handle, lack of safety, and ongoing practical support needs (i.e., finances, housing, children's needs) may all interfere with or impair the energy needed to emotionally and cognitively process the traumatic event. Before a CISD is provided, the debriefer should assess the above factors and discuss with the victim as well as those who know him/her when the best timing for a CISD would be. This might mean 7-14 days or even longer after the event. When crises occur in an overseas setting, the handling of logistics may take much longer and this will need to be taken into account. In the case of a team which is evacuated from a war torn area, the timing of the debriefing is less important than making sure that everyone who should be there is able to attend.
• Re-traumatization — An essential part of CISD has been helping the person to describe what happened to them and to go into details about their thoughts and emotions during the event. Some people may actually begin to relive the experience almost as if they were back in the trauma as they describe it. In the context of therapy, this can be a healthy and therapeutic process. But, in order for it to be healing, it has to be accompanied by other therapeutic interventions that bring a sense of safety and calm to the person. In the absence of trained mental health professionals and because CISD is not considered "therapy", it's possible that a person would enter into a very intense emotional state and that the structured debriefing would then end before they have had a chance to experience a sense of calm and safety. This abrupt termination of an emotional process would increase rather than decrease the person's anxiety and could actually lead to more problems down the road. This would be especially true for people who have had past unresolved trauma, people who have anxiety disorders, and people who are experiencing very high levels of anxiety and arousal during or immediately following the traumatic event. So, there are several important recommendations for this issue. One is that if the debriefer notices that a person seems particularly agitated or anxious before the CISD, it's very possible that they are not a good candidate for CISD at that time and it would be best to consult with a mental health professional before going any further. Secondly, if a person gets into very intense emotions during the CISD and seems to be re-experiencing the event, the debriefer should try to help them get to a place of safety, security, and calm before they leave. This is not done by cutting them off or ending the CISD prematurely, but rather gently guiding them back to the truths and facts that will help them feel grounded, safe, and secure. Participants can be given the opportunity to discuss and make sense of their emotions but should not be pressured or pushed to vividly re-enter the memory.
• Vicarious traumatization — This can occur when someone is exposed to a trauma by listening to a particularly horrible or graphic traumatic story that then triggers an emotional reaction that is very similar to the reactions of direct trauma victims. Let's say, for example, that a group of people has been robbed but several from the group directly witnessed a murder during the robbery. As the whole group is debriefed and telling their story, the few that saw the murder describe graphic details of how the person died. This may be unnecessary information for the other victims, particularly those who are more vulnerable and are already having difficulty processing the trauma they went through. A recommendation here would be to form several groups and debrief them separately according to the intensity of traumatic exposure. It might also be appropriate to set limits on the details of what is shared in the group setting but to be sure to give each person an individual opportunity later to share all the details they need to. This would need to be done sensitively and without shaming or shutting down the person who may be sharing the details. The risk of vicarious traumatization is also high for the debriefers and they will need to work through their own emotional reactions to the stories they have heard.
• Superficiality — CISD has had such popularity that some have been tempted to think of it as a "cure-all" for trauma. Therefore, a danger for debriefers or for trauma victims would be to assume that a CISD has adequately addressed all of the traumatic reactions such that a person does not need follow up care. CISD needs to be seen as one response in a series of responses to the person with each individual potentially requiring a different range of responses. The level and intensity of intervention needed will depend on things like the severity and intensity of the trauma as well as the victim's history, personality, and support system. Some will do fine with no debriefing, some will benefit from a debriefing only, and others will need more specialized therapy in order to recover from the traumatic experience. CISD should not be seen as a substitute for therapy. And those who would benefit from therapy should not be seen as weaker or less resilient than those who would not. In fact, the opposite may be true. If peer responders are providing the debriefing in the absence of mental health professionals, they should be well trained to recognize PTSD symptoms and to understand how to consult with and make a referral to a mental health professional when needed.
What might be the benefits of offering CISD?
Given the current state of the research, it cannot be reliably said that CISD prevents the development of Post-traumatic Stress Disorder, Major Depression, or any other pathological reaction. Still, many people report that CISD has helped them and that they subjectively feel better afterwards. What is the reason for this and how could these positive effects be measured? Some have suggested that debriefings or at least some kind of "psychological first aid" do accomplish the goal of providing support, education, screening, and linkage to resources (Raphael & Ursano, 2002).
It has been demonstrated that one's level of social support as well as one's perception of organizational support during and after a crisis affects their ability to cope with it and their overall resilience (Forbes & Roger, 1999; Keane et. al., 1985). A specific goal of CISD then should be to improve or affirm one's support system. There are many opportunities during debriefings to highlight the support that peers have given each other during a crisis. Also, debriefers can be in the unique role of coaching organizational leaders to provide ongoing support to trauma victims. In September 2002, the Mobile Member Care Team (MMCT) was facilitating a workshop in Bouake , Ivory Coast with eighteen people when we suddenly found ourselves in the middle of a war, caught between the rebels and government forces. For eight days we were under siege before we were evacuated by French troops. When we returned to Abidjan we had a debriefing time together as a whole group. The four leaders of the workshop who had become the crisis management committee during the crisis took time in that group debriefing setting to acknowledge each group member's unique role and contribution in the managing of that crisis. Each person was affirmed for the ways that they contributed to the coping and strength of the group. The group members reciprocated by affirming and praising the leadership for how they had handled the crisis as well as cared for the members.
The educational aspects of debriefing can also add to a person's sense of mastery and control, which is directly related to their ability to cope with a situation. Debriefers who have been trained by MMCT are given several handouts to give to trauma victims. The handout entitled "Common Post-Trauma Reactions and Symptoms" (found at www.mmct.org ) gives people an opportunity to identify, anticipate, and talk about normal reactions to trauma. This is a key aspect of the debriefing and provides something tangible for both adult and child victims.
Linkage to resources is another beneficial aspect of debriefings. This might include facilitating people to: find peers who have experienced similar things; have meaningful contact with family and friends who are able to be supportive; be reminded of spiritual resources; or arrange follow up appointments with a mental health professional.
Another potential benefit of CISD is that it can help victims begin to articulate what has happened to them and to face it in a way that protects them from using avoidance as a defense mechanism. Avoidance is one aspect of PTSD and is often a key element of anxiety disorders. If the person can be assisted in talking about what has happened in an atmosphere of trust, safety, and low anxiety, it will counteract the tendency to use avoidance as a means of self-protection.
CISD also gives the debriefer the opportunity to observe and assess those who may need further care. The crisis training provided by the Mobile Member Care Team in West Africa includes skill building in crisis assessment as well as debriefing. Assessing a person's risk for complications following trauma is a key element of crisis intervention and an essential skill for potential debriefers.
CISD in context
Crisis intervention involves a spectrum of activities and responses that cover a time period before, during, and after the crisis. Before the crisis, behaviors that focus on preparation for crisis, building trust, deepening relationships, and enhancing coping resources are helpful. During the crisis, the focus is on survival and the practical aspects of managing the situation well. After the crisis, the victims need emotional support, the presence of caring and clear leadership, good information sharing, and any psychological intervention that will be beneficial. One must not minimize or forget the importance of practical supports, which sometimes are better remembered, and even more appreciated than professional interventions. This might include provision of money, replacement of personal items, care of children, options for future employment, or the opportunity to continue their work even if from a distance (Fawcett, 2002).
Leaders are in a unique role of being able to give people time off, tweaking the budget to give more financial resources, writing a letter to supporters, arranging for meals, etc. When MMCT evacuated from Ivory Coast , we had to leave behind all of our furniture, office equipment, and many of our personal belongings. As we began to set up a new house and office in Ghana we were faced with financial and logistical obstacles. Our leaders supported us in many ways but two practical ways stand out to me. One of our leaders submitted a request for special funding such that three months of our rent in Abidjan was paid for which provided substantial financial assistance. Another leader and several colleagues in one of our supporting missons went to Abidjan when we were not able to go and packed our possessions into a container which was later shipped to Ghana . These kinds of actions speak volumes of care and concern and definitely facilitate the healing process.
What can a leader/administrator do?
Given that pre-crisis preparation has been cited as an important variable in coping with crises (Danieli, 2002), it seems a wise investment of time and resources for leaders to make sure that they and others who will give care during a crisis should receive crisis training. The training received in the MMCT workshops (Member Care While Managing Crises and Peer Response Training) includes relevant content areas such as crisis theory and assessment, theology of suffering and risk, crisis management, development of crisis policies and procedures, and debriefing. Training offered by Crisis Consultants International also has relevant content areas including risk assessment and crisis contingency planning.
Other relevant trainings would be those that focus on team building, team cohesion, and leadership skills. In elaborating on leadership styles important in times of crisis, Fawcett (2002) asserts that team cohesion and trust in competent leadership—factors that must exist before the crisis—are key elements in promoting healthy adaptation to the crisis event. In recommending pre-crisis training for leaders he mentions things such as team cohesion, morale, and consultative leadership style as a way of increasing social support and reducing stress. One of the comments that the MMCT leadership heard several times from the workshop participants following our eight day siege in Bouake was that they felt very calm and secure during the crisis because of their perception that the leadership team was calm, competent, and unified.
Since trust, strong relationships, and managing stress are such key elements of coping with crisis (Noy, 1991), workshops such as the Sharpening Your Interpersonal Skills (SYIS) workshop ( www.relationshipskills.com ) could benefit not just leaders but all missionaries on the field. In this workshop, participants begin to identify how to be better trust builders, how to manage stress, and how to address conflicts in relationships. Mission leaders can play a key role in encouraging their members to get this kind of training and can follow up to find out how these principles are being applied.
In World Vision's studies related to the efficacy of debriefing they found anecdotally that the level of organizational support was actually more important than the debriefings (Fawcett, 2002). Specifically the staff reported that the presence of a senior manager during and following a critical event was perceived as a demonstration of organizational support and care and was a significant factor in how they coped with the trauma. To use the Bouake siege as an example again, one of the things that helped sustain us and give us courage during the siege was the frequent phone calls of one of our mission leaders. He called us daily and sometimes hourly just to find out how we were doing and to assure us that he was praying for us, concerned for us, and committed to doing everything in his power to get us out of there. I'm sure there were many times when he felt powerless and frustrated but he still reached out and his phone calls made a difference. Leaders can make a big impact through phone calls, e-mails, and personal visits when they are communicating support, concern, and care as well as a commitment to help and stay involved.
Some final conclusions and recommendations
As we've taken a closer look at psychological debriefing, five areas have been identified that could contribute to the process being harmful for recipients. These areas are lack of choice, poor timing, retraumatization, vicarious traumatization, and superficiality. Recommendations have been given to try to help prevent these potential pitfalls from occurring with the debriefings we provide on the mission field. In summary, the recommendations include: - Improve the process of educating people (leaders and victims) about what CISD is and what it is not and give trauma victims multiple opportunities over time to receive debriefing.
- Before a CISD is provided, debriefers should assess the victims' level of fatigue, practical support needs, sense of being overwhelmed, and anxiety levels in order to determine if it is the right timing for the debriefing. Consult with a mental health professional if there are any questions about the level of anxiety.
- When debriefing participants express very intense emotions in the debriefing, help them get to a place of safety, security, and calm before they leave the session. Debriefers do not want to force or coerce a person to express intense emotions, but also don't want to cut them off when they do or communicate in some way that it is wrong or detrimental to express those emotions.
- Consider doing separate debriefings with smaller groupings according to the intensity of traumatic exposure so that people do not have to hear gory details of events that did not directly involve them. Also, children do not need to hear all the details of the adult's thoughts and fears during a shared event.
- Remember that CISD is one part of a broader spectrum of crisis intervention. Take care to provide follow up and to assess if the person needs more intervention beyond a one-session debriefing.
- As leaders recognize their unique and critical role in providing support, they can facilitate spiritual, practical, and emotional care that may have an even more lasting impact than debriefings.
- Those of us who are on the mission field providing debriefings need to begin the process of doing research that will examine the validity and value of providing CISD to trauma victims.
We must continue to search for the best and most excellent ways of caring for those who have been traumatized and injured on the battlefield. Some would say that offering a poor debriefing is better than offering nothing at all. But, preliminary research seems to indicate that a debriefing that is done poorly could actually be worse than offering nothing at all. The critical research gives us a sober warning—debriefings need to be done by well-trained personnel and within the parameters for which it was intended. If they are offered in this way, they can provide a very valuable support and structure for overseas workers to process and manage the distress that comes from the traumas they endure. The above recommendations are made with the goal of continuing to grow and improve on the crisis intervention services offered to cross cultural workers experiencing traumatic events so that they will be encouraged to continue their works of service.
References
Bisson, J., McFarlane, A., & Rose, S. (2000). Psychological debriefing in E.B. Foa, T.M. Keane, & M.J. Friedman (Eds.), Effective Treatments for PTSD. New York : Guilford Press.
Carr, K.F. (1994). Trauma and Post Traumatic Stress Disorder among missionaries. Evangelical Missions Quarterly, July, 246-255.
Danieli, Y. (2002). Sharing the front line and the back hills. Amityville , New York:Baywood Publishing Company, Inc.
Dyregrov, A. (1997). The process in psychological debriefings. Journal ofTraumatic Stress, 10(4), 589-605.
Ehlers, A. & Clark, D. (2000). A cognitive model of posttraumatic stress disorder. Behavioral Research and Therapy, 38, 319-345.
Everly, G. & Boyle, S. (2001). Critical Incident Stress Debriefing (CISD): AMeta-analysis. Ellicott City , MD : International Critical Incident StressFoundation.
Fawcett, J. (2002). Preventing broken hearts, healing broken minds in Danieli, Y.(Ed.). Sharing the front line and the back hills. Amityville , New York: Baywood Publishing Company, Inc.
Forbes. A. & Roger, D. (1999). Stress, social support and fear of disclosure. British Journal of Health Psychology, 4, 165-179.
Horowitz, M, Wilner, N., & Alvarez, W. (1979). Impact of event scale: A measure of subjective distress. Psychosomatic Medicine, 41, 209-218.
Jenkins, S.R. (1996). Social support and debriefing efficacy among medical workers After a mass shooting incident. Journal of Social Behavior and Personality, 11, 477-492.
Keane, T.M., Scott, W.O., Cavoya, G.A., Lamparski, D.M. & Fairbank, J.A. (1985). Social support in Vietnam veterans with Posttraumatic Stress Disorder:A comparative analysis. Journal of Consulting and Clinical Psychology, 53, 95-102.
Litz, B., Gray, M., Bryant, R. & Adler, A. (2002). Early interventions for trauma: Current status and future directions, Clinical Psychology Science & Practice, 9: 112-134.
Lovell, D. (1999). Evaluation of Tearfund's critical incident debriefing process. Internal paper produced for Tearfund, Teddington , UK .
Lovell-Hawker, D. (2002). Guidelines for crisis and routine debriefing in O'Donnell, K. (Ed.). Doing Member Care Well. Pasadena , CA : William Carey Library.
Mitchell, J. (1983). When disaster strikes: The critical incident debriefing process. Journal of the Emergency Medical Services, 8, 36-39.
Noy, S., (1991). Stress and personality as factors in the causation and prognosis of Combat reaction, in Handbook of Military Psychology, R. Gal & A. Mangelsdorff (Eds.), Chichester , United Kingdom : John Wiley.
Pennebaker, J., & Beall, S. (1986). Confronting a traumatic event: Toward an understanding of inhibition and disease. Journal of Abnormal Psychology,95, 274-281.
Raphael, B. & Ursano, R. (2002). Psychological debriefing in Danieli, Y.(Ed.). Sharing the front line and the back hills. Amityville , New York: Baywood Publishing Company, Inc.
Raphael, B. & Wilson, J. (Eds.). (2000). Psychological debriefing: TheoryPractice and evidence. London : Cambridge University Press.
Rose, S., Bisson, J., Wessely, S. Psychological debriefing for preventing postTraumatic stress disorder (PTSD) (Cochrane Review). In The CochraneLibrary, Issue 1 2003. Oxford , UK : Update Software.
Wee, D. (1995, April). Stress responses of emergency medical services personnel Following the Los Angeles civil disturbance. Paper presented to the 3 rd World Congress on Stress, Trauma, and Coping in the Emergency Services Professions, Baltimore , MD.
Wessely, S., Rose, S., & Bisson, J. (2000). Brief psychological interventions("debriefing") for trauma-related symptoms and the prevention of post traumatic stress disorder (Cochrane Review). In The Cochrane Library, Issue 3. Oxford , UK: Update Software.
Return to Previous Page
|