Additional Criteria Considered When Evaluating Studies

Studies of diagnosis must meet these additional criteria:

• Inclusion of a spectrum of participants, some, but not all of whom have the disorder or derangement of interest.
  
• Diagnostic (gold) standard (e.g., diagnosis according to DSM IV or ICD-10 criteria after assessment by clinically qualified reviewer) preferably with documentation of reproducible criteria for subjectively interpreted diagnostic standard (e.g., report of statistically significant measure of agreement among observers)
  
• Each participant must receive both the new test and some form of the diagnostic standard
  
• Interpretation of diagnostic standard without knowledge of test result
  
• Interpretation of test without knowledge of diagnostic standard result
  
• Analysis consistent with study design.
  

Review articles must meet these additional criteria:

• Statement of the clinical topic
  
• An identifiable description of the methods indicating the sources
  
• Explicit statement of the inclusion and exclusion criteria applied for selecting articles for detailed review.
  
• At least one article included in the review must meet the above noted criteria for treatment, diagnosis, prognosis, causation, quality improvement, or the economics of healthcare programmes.
  

Studies of prognosis must meet these additional criteria

• Inception cohort (first onset or assembled at a uniform point in the development of the disease) of individuals, all initially free of the outcome of interest
  
• Follow up of at leat 80% of patients until the occurrence of a major study end point or to the end of the study
  
• Analysis consistent with study design.
  

Studies of causation must meet these additional criteria:

• Observations concerning the relationship between modifiable exposures and putative clinical outcomes
  
• Prospective data collection with clearly identified comparison group(s) for those at risk of the outcome of interest (in descending order of preference, from randomized controlled trials, cohort studies with case by case matching or statistical adjustment to create comparable groups, or nested case control studies)
  
• Masking of observers of outcome to exposure (this criterion is assumed to be met if the outcome is objective)
  
• Analysis consistent with design.
  

Articles meeting the criteria set out above are abstracted according to the procedure for more informative abstracts with the following modification: abstracts can be up to 440 words in length; and each is reviewed by an expert in the content area covered by the article and a commentary is added to provide the context of the article in the research that has preceded it; to provide any important methodological problems that affect interpretation; and to provide recommendations for clinical application. The author of the article is given the opportunity to review the abstract and commentary before publication.