Lecture 30 - Systematic reviews

Question 1

Clinical research - Ideal world

Answer 1

A perfect study answers the clinical question precisely with no bias or confounding and has precise estimate with narrow confidence intervals

Question 2

Clinical research - Real world

Answer 2

Multiple studies are found but they have limitations like bias, confounding, lack of precision and generalisability issues. The truth is not always clear

Question 3

What is systematic reviews

Answer 3

A research methodology used to collect and synthesis results across multiple studies to minimise bias. It follows a clear, replicable process and aims to provide an unbiased summary of evidence.

Question 4

Narrative review vs Systematic review

Answer 4

Narrative review - May be opinion-driven, lacks transparency and is not easily replicable
Systematic review - Transparent, replicable, systematic, and based on predefined method that minimise bias

Question 5

Why are systematic reviews done?

Answer 5

• Collate evidence and synthesise their results
• Systematic review methods reduce bias that otherwise be encountered with narrative reviews

Question 6

Protocol methods - systematic reviews

Answer 6

1. question - formulate clear question
2. relevance - why is it important to do this review
3. objectives - to summarise evidence on the association
4. search strategy - Replicable and transparent
5. selection criteria - inclusion and exclusion criteria of studies
6. eligibility screen
7. risk of bias - according to prespecified criteria
8. data extraction
9. data synthesis - Data synthesis may involve meta-analysis

Question 7

What is meta analysis

Answer 7

A statistical method used to combine data from multiple studies to provide a more precise estimate of the effect size. Its often included in systematic reviews to pool results.

Question 8

Why is the assessing the risk of bias important in systematic reviews

Answer 8

Studies with high bias may distort results, leading to incorrect conclusion.

Question 9

Heterogeneity and homogeneity

Answer 9

• Heterogeneity: when result vary significantly across different studies
• Homogeneity: when results are consistent across studies

Question 10

Interpretation

Answer 10

• Principal findings
• Limitations to the evidence
• Implication (practice, research)

Question 11

Challenges of systematic

Answer 11

• Publication bias
• Heterogeneity
• Poor quality trials/studies
  leads to
• Conflicting reviews
• Inconclusive results

Question 12

Important of systematic reviews

Answer 12

• They provide a comprehensive, unbiased synthesis of available of evidence
• Reproducibility, rigour
• transparent limits
• Gaps in knowledge
• Basis for decisions