Table 2 Common practical and conceptual challenges and examples of resources to address these
Type of challenge | Examples of resourcea | |
|---|---|---|
Practical | Inconsistent language, no consensus on definitions, multidisciplinary | • Protocol template with guidance • Taxonomy of relevant outcomes • Describing results document • How to GRADE document |
Disparate data, often unsuitable for statistical pooling | • Meta-analysis document • Narrative data synthesis and analysis guide • Heterogeneity and subgroup analysis document | |
Large size (many included studies) | • Data extraction template • Review template with guidance | |
Many outcomes, measured in many different ways | • Taxonomy of relevant outcomes • Protocol template with guidance • Summary of findings document | |
Conceptual | Scope of review questions broad (lumped) or narrow (split) | • Protocol template with guidance |
Intervention purpose and delivery highly variable | • Protocol template with guidance • Data extraction template | |
Comparisons complex and difficult to identify | • Identifying comparisons document | |
Causal pathways or mechanisms socially complex or unknown | • Examples of theoretical models document • Taxonomy of relevant outcomes | |