Step 1: Think about the rationale

In this step we think about if we want to conduct a systematic review

Why should we do an evidence synthesis

Identify gaps
establish an evidence base for best-practice guidance
help inform policymakers and practitioners

Topic

For the creation of a systematic review you obviously need a topic Possible topics for systematic reviews - Conditions, categories and measures - Rates and trends - Correlates - Predictors - Causes and effects - Cost effectiveness - Comparative effectiveness - Generalizability

Determine the type of review

You need to think about what type of synthesis you want to do. - Depends on time, resources, aim, depth required

Systematic review

A systematic review attempts to identify, appraise and synthesize all the empirical evidence that meets pre-specified eligibility criteria to answer a specific research question. The purpose of a systematic review is to provide a meticulous summary of all available primary evidence on a research question.

Key charateristicts: - A clearly stated set of objectives - Pre-defined eligibility criteria for studies - A explicit, reproducible methodology - A systematic search that attempts to identify all studies that would meet the eligibility - Assessment of the validity of the findings - A systematic presentation and synthesis of the characteristics and findings

Problems of synthesis studies

Heterogeneity

Synthesis studies suffer from heterogeneity, that is the differences between the studies

Publication bias

All synthesis studies have a publication bias to some degree
You can use a funnel plot to have a look

Sensitivity analysis

Usually certain studies with lower quality are exluded. Does this change the results