[UNDER CONSTRUCTION] In the 7th building block Evaluation[economic & comparative] two types of intervention comparison are used.
Comparison 1: Quantitative multi-intervention effect size meta-analysis
This type of comparison relies on effect sizes being available for high level outcomes from all of the interventions which are being compared. If they are not available then this type of analysis cannot be done. The Prerequisites building blocks 5-8 diagram here sets out the prerequisites for elements within the Systematic Outcomes Analysis building blocks. If Comparison 1 is being used by decision makers as the major factor in selecting between different interventions, this only makes sense if one instance. This is where the ease of undertaking E[outcome] studies which produce effect sizes (Designs 1-4 here) is not very different for the different interventions. If it is not then decision makers will be biasing their decisions in the direction of the easy undertaking E[outcome] Designs 1-4 rather than rational decision making on the basis of a critical assessment of the strengths and weaknesses of the evidence available. Comparison 1 decision making is likely to enhance decision making in situations such as the comparison of pharmaceuticals, but less suited to situations where decision makers are attempting to compare very different interventions (e.g. individual interventions versus community programs).
Comparison 2: Mixed qualitative/quantitative multi-intervention comparison analysis
This comparison covers a diverse range of different type of comparison between interventions. This includes general reviews of what works and what does not work, summaries of qualitative studies etc. It is not restricted to just qualitative findings because there is no reason why quantitative results should not be also considered in such reviews.