Criteria | Necessary for inclusion in meta-analysis confirming moderator effects | Necessary for inclusion in meta-analysis exploring moderator effects | Criteria for the judgment of yes | Exceptions |
---|---|---|---|---|
Was the analysis a- priori | √ |  | Mention of explicit hypothesis planned in protocol stating which sub-groups will be tested for which outcome | Criterion is not fulfilled in cases where the protocol includes a considerably large set of stated hypotheses or vague hypotheses (e.g. psychological factors will interact with treatment allocation') |
Was selection of factors for analysis clinically plausible and either or both: | √ |  | A description of theoretical background, or reference to other published evidence leading to the hypothesis | Is not fulfilled in cases where the meta-analyst considers the theory/evidence to be weak, but should not form reason for exclusion. |
   i) Theory based |  |  |  |  |
   ii) Evidence based |  |  |  |  |
Were moderators measured prior to randomisation? | √ | √ | Specific statement that baseline measurement occurred prior to randomization | Not applicable for baseline factors that do not change over time, such as gender, or for cluster randomization. |
Adequate quality of measurement of baseline factors | √ | √ | If there is published evidence to support good measurement properties of measurements for target population, according to meta-analysts' protocol. | Is not fulfilled where there is inadequate variability in baseline measure. |
Contains an explicit test of the interaction between moderator and treatment | √ | √ | Ideally, Report a pooled effect size with 95% confidence intervals. Other acceptable analysis includes regression etc. | Not fulfilled when sub-groups are tested separately, or in excessive multiple testing. |