substitute for the current evidence, then the current evidence would be judged “inadequate.”

Although all of these determinations were based on recognized principles and guidelines for evaluating evidence, there is no established algorithmic approach to these classifications and the committee did not use one. Instead, it attempted to be as transparent as possible in describing the foundations of its judgments, and these are reflected both in the evidence tables and in the “Synthesis” paragraphs immediately preceding statement of the conclusion for each treatment modality presented in Chapters 3 and 4. The evidence tables include population descriptors, sample size by arm and total, handling of missing data and dropout rates, information about blinding, PTSD outcome measure change data,4 loss of PTSD diagnosis data, and finally, a listing of a study’s principal limitations.

SUMMARY OF THE LITERATURE REVIEWED IN MAKING CONCLUSIONS

The final set of studies reviewed by the committee consisted of 89 total, with 37 studies of pharmacotherapies and 52 studies of psychotherapies. All studies were randomized controlled trials. Studies ranged in sample size from fewer than 20 to more than 500 and were conducted with a variety of patient populations: male, female, and mixed populations; various traumas (combat- and noncombat-related); more recent onset of the disorder and chronic PTSD; and so on. Studies reviewed also employed a range of PTSD outcome measures, from frequently used, validated measures such as the Clinician Assessment PTSD Scale (CAPS) and the Impact of Events Scale (IES), to more idiosyncratic measures sometimes developed for a specific study. The studies reviewed by the committee included a large number of outcome measures; a summary table of the measures most often encountered in the literature is provided in Appendix C.

SUMMARY OF EXISTING SYSTEMATIC REVIEWS AND META-ANALYSES

In addition to its review of individual research studies, the committee examined a number of systematic and qualitative reviews and meta-analyses. Some reviewed both psychotherapies and pharmacotherapies,

4

PTSD outcome measure change data were obtained either directly from the study, when provided, or by subtracting data reported at treatment completion (not follow-up data) from baseline data (before treatment began). Average baseline score when reported or when baseline scores for all arms are nearly the same; otherwise, baseline scores listed individually in order of arm.



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