Table 2 Items extracted from the eligible umbrella reviews

Metadata

 General characteristics

First author

Date of publication

Journal of publication

Introduction

 Research scope

Research topic

Study designs of interest

Methods

 Literature search

Bibliographic databases

Date of literature search

Handling of SRMAs on overlapping research question

Quantification of the overlap in the primary studies across overlapping SRMAs

Update of eligible SRMAs

Search for Mendelian randomization studies^a

 Statistical methods

Narrative discussion of SRMAs without statistical analysis

Presence of meta-analysis

Meta-analytic model applied

Statistical significance threshold

Between-study heterogeneity

Tests for bias

95% prediction intervals

Sensitivity analyses

 Risk of bias

Qualitative assessment of primary studies

Qualitative assessment of eligible SRMAs

Assessment of the strength of the evidence

 Open science principles

Protocol pre-registration

Data sharing agreement

Results

Number of eligible SRMAs

Number of meta-analyses performed

Number of statistically significant associations

Reporting of the eligible SRMAs

Flow chart for study selection

Reporting of results in tabular and/or visual format

Discussion

 Existing literature

Discussing previous umbrella reviews^a

Discussing Mendelian randomization studies^a