Identifying the evidence

Laura MacdonaldHealth Protection Scotlandlaura.macdonald5@nhs.net

Where do I start?

Ask the right questions

• Determine the scope of the guidance• Get input from guideline development team and key

stakeholders• Prioritise! • Formulate key questions

– Population

– Intervention

– Comparison (control)

– Outcome

Write a protocol

• Why? – Background and context

• What?– Aims and objectives– Key questions– Outputs

• How? – Search strategy– Inclusion/exclusion criteria– Screening– Critical appraisal– Recording and organisation

Searching for literature

• Select resources based on topic• Resources

– Knowledge Network• MEDLINE• Embase• CINAHL

– Cochrane Library – Grey literature databases– Guideline databases...etc

Searching for literature

• Search terms:– Different terminology – Controlled vocabulary (e.g. MeSH)– Free text terms

• Advanced searching– Combine search terms using Boolean operators– Apply limits

• Adapt your searches for each resource• Save your searches

Inclusion/exclusion criteria

• Exclusion versus inclusion criteria • Types of study• PICO framework

– Population– Intervention– Comparison (control)– Outcome

• Date • Language

Screening

• Screen search results against inclusion/exclusion criteria• Time consuming and tedious! • First screen

– Title and abstract• Second screen

– Full text • Remaining items – in the review

Recording and organisation

• Transparent process • Keep a record of what you do

– Changes to protocol– Search terms– Search dates– Excluded items– Reasons for excluding items

• Systematic review management software (e.g. EPPI-Reviewer; RevMan)

Critical Appraisal

• Structured process to systematically assess evidence:– Quality – Validity– Generalizability– Applicability– Conclusions etc

• Range of critical appraisal tools available (e.g. SIGN)

Thank you