Umbrella Review

Synthesize evidence from multiple systematic reviews to provide the highest level of evidence summary.

What is an Umbrella Review?

An umbrella review (also called "overview of reviews"):

• Synthesizes existing systematic reviews
• Compares findings across reviews
• Identifies highest quality evidence
• Resolves conflicting conclusions
• Provides comprehensive overview

When to Use

Ideal For

• Clinical guidelines: Synthesizing evidence across interventions
• Policy development: Broad topic overview
• Research gaps: Identifying missing systematic reviews
• Quality assessment: Comparing review methodologies
• Evidence summaries: Executive-level overviews

Requirements

• Multiple existing systematic reviews
• Sufficient review overlap
• Need for synthesis
• Resources for quality assessment

The Overlap Challenge

Why Overlap Matters

Multiple systematic reviews often:

• Include the same primary studies
• Reach different conclusions
• Vary in quality
• Use different methods

EvidAI's Solution

Intelligent overlap management:

• Automatic detection: Identifies shared studies
• Citation mapping: Visualizes relationships
• Statistical adjustment: Prevents double-counting
• Quality weighting: Prioritizes better reviews

Umbrella Review Workflow

Phase 1: Protocol

• Define broad question
• Specify review types to include
• Plan overlap handling
• Select quality tool (AMSTAR-2)

Phase 2: Search for Reviews

• Cochrane Library
• PROSPERO
• PubMed (systematic review filter)
• Database of Systematic Reviews

Phase 3: Review Selection

• Apply eligibility criteria
• Focus on systematic reviews
• Include meta-analyses
• Exclude narrative reviews

Phase 4: Quality Assessment

AMSTAR-2 Assessment AI-assisted evaluation of:

• Protocol registration
• Search comprehensiveness
• Study selection process
• Risk of bias assessment
• Meta-analysis methods
• Publication bias
• Conflict of interest

Phase 5: Overlap Analysis

EvidAI's unique features:

• Primary study identification
• Cross-review mapping
• Overlap visualization
• Corrected synthesis

Phase 6: Evidence Synthesis

• Quality-weighted conclusions
• Certainty assessment
• Conflicting findings resolution
• Gap identification

Deliverables

Umbrella review outputs:

• ✅ Protocol documentation
• ✅ PRISMA flow (for reviews)
• ✅ Review characteristics table
• ✅ AMSTAR-2 results
• ✅ Overlap matrix
• ✅ Evidence summary by outcome
• ✅ Certainty assessments
• ✅ Recommendations

Best Practices

Planning

• Ensure sufficient reviews exist
• Define clear inclusion criteria
• Plan overlap handling
• Consider guideline standards

Execution

• Assess all reviews with AMSTAR-2
• Document overlap thoroughly
• Weight by quality
• Address disagreements transparently