Best Evidence Topics

Review or meta-analysis

van Emmerik AA, Kamphuis JH, Hulsbosch AM et al.
Single session debriefing after psychological trauma: a meta-analysis
Lancet
2002;360:766-771.
  • Submitted by:Simon Carley - Consultant in Emergency Medicine
  • Institution:Manchester Royal Infirmary
  • Date submitted:7th May 2003
Before CA, i rated this paper: 8/10
1 Objectives and hypotheses
1.1 Are the objectives of the study clearly stated?
  Yes. It is to look at the effect of single session debriefing after trauma to see if it has any effect on the subsequent development of PTSD.
2 Design
2.1 Is the study design suitable for the objectives?
  Yes. This is a review article looking at a specific topic. There is research out there so it seems reasonable to review it rather than start all over again with a new trial.
2.2 Were the search methods used to locate relevant studies comprehensive?
  Yes. they have looked at databases and the grey literature. Specifically:-
Medline
PsyInfo
PubMed
Hand Search Journal of Traumatic Stress
Reference lists of books and articles
They did not however contact authors or look at conference abstracts
2.3 Was this the right sample to answer the objectives?
  Yes. They were explicit and open about which studies they accepted. Specifically they only looked at single interventions and for within 1 month of the trauma.
2.4 Is the study large enough to achieve its objectives?
  Difficult to answer as in a metanalysis you get what you are given. The final data suggests that if an effect is present then it a small one, so probably yes.
2.5 Were all the studies accounted for?
  Yes there is an explanation that they found 29 studies but excluded 22 for valid reasons.
2.6 Were all appropriate outcomes considered?
  Probably
2.7 Has ethical approval been obtained if appropriate?
  Not appropriate
3 Measurement and observation
3.1 Is it clear what was measured, how it was measured and what the outcomes were?
  What - a variety of methods and outcomes were used. An unfortunate problem with this sort of study. The principle differences in techniques were divided into CISD (critical incident stress debriefing) and non-CISD.
How - a variety of scales used, though these are explained.
Outcomes - large variation on when the outcomes were measures (24 hours - 13 months) this is a flaw.
3.2 Were explicit methods used to determine which studies to include in the review?
  Yes. They are described. They admit to using lower quality studies as there was so little out there.1
3.3 Was the selection of primary studies re-producible and free from bias?
  Probably not
3.4 Was the methodologic quality of the primary studies assessed?
  Yes. Not formally though.
3.5 Are the measurements valid?
  Variable
3.6 Are the measurements reliable?
  Probably. Approved methods used.
3.7 Are the measurements reproducible?
  Probably approved methods used
4 Presentation of results
4.1 Are the basic data adequately described?
  Reasonable - table 1. has details. More could be given regarding the specific type of stressor
4.2 Were the differences between studies adequately described?
  There is a lot of variation which is discussed. This is a problem with this study.
4.3 Are the results presented clearly, objectively and in sufficient detail to enable readers to make their own judgement?
  Reasonably so
4.4 Are the results internally consistent, i.e. do the numbers add up properly?
  Yes
5 Analysis
5.1 Were the results of primary studies combined appropriately?
  Difficult as so variable, they authors have combined the effects of different interventions, measures and outcomes. This is dodgy. However, they find a consistent effect so it may be of value
5.2 Has a sensitivity analysis been performed?
  N/A
5.3 Were all the important outcomes considered?
  Not enough long term data. What about the effect on lifestyle?
5.4 Are the data suitable for analysis?
  Questionable
5.5 Are the methods appropriate to the data?
  Yes
5.6 Are any statistics correctly performed and interpreted?
  Yes
6 Discussion
6.1 Are the results discussed in relation to existing knowledge on the subject and study objectives?
  Yes. the discussion is well presented and explains the results well. There is a clear examination of where this study fits into the literature
6.2 Is the discussion biased?
  No
7 Interpretation
7.1 Are the author's conclusions justified by the data?
  Yes
7.2 What level of evidence has this paper presented?
  Moderate
7.3 Does this paper help me to answer my problem?
  Yes. I do not think after reading this that we should strive to offer single session debriefings.
After CA, i rated this paper: 4/10
8 Implementation
8.1 Can any necessary change be implemented in practice?
  Yes. Avoid this method of PTSD prevention
8.2 What aids to implementation exist?
  N/A
8.3 What barriers to implementation exist?
  N/A