Table 4

The components, rating criteria and symbol, and categories used in summarising the study evidence in the current study
Domain 1 Domain 2 Global (GRADE)
Decision Components Subject of public reporting (or study population) and study participants (sample) Types of study (i.e. study designs) Components from Domain 1 & 2 as well as implementation and adherence to intervention, dose–response gradient, precision and validity of the outcomes, uncertainty of direction of the results.
Rating criteria How well does the study sample represent the study population? How strong is the study design both in terms of its external and internal validity? How much weight does the current study add to the evidence-base taking into considerations of all the components above?
Symbol used & categories of rating 1*: no overlap 1*: weakest design √: little weight
2*: modest overlap 2*: moderate design √√: moderate weight
3*: large overlap 3*: strong design √√√: great weight
4*: complete overlap 4*: strongest design

Chen et al.

Chen et al. BMC Health Services Research 2013 13:211   doi:10.1186/1472-6963-13-211

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