SYSTEMATIC REVIEW METHODS

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Unit 2

SYSTEMATIC REVIEW

METHODS

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1. Identify the components to address in

developing inclusion and exclusion criteria for a systematic review question about the effectiveness of an intervention.

2. Identify the components of a

comprehensive systematic review search strategy.

OBJECTIVES: UNIT 2

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INCLUSION VS EXCLUSION CRITERIA

Inclusion

what a study need to address in order to be included in the review

Exclusion

situations and circumstances in which study will not be included in the review

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INCLUSION/EXCLUSION:

CONSIDERATIONS

Review question

Broad vs. narrow

Consistent decisions

Reduce bias

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Most robust design for the review question

Including non-randomized studies in Intervention Reviews

Limitations

Reasons

Based on review question

Lack of randomized studies

INCLUSION/EXCLUSION: STUDY DESIGN

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Experimental study where participants are

allocated to interventions using methods that are not random

 Non-randomized trial

Observational study with a control group

 Use of different interventions is not allocated by the researcher

 Controlled before-after study

 Cohort study

 Case-control study

Observational study without a control group

 Cross-sectional study

 Case series

Case reports

NON-RANDOMIZED STUDIES

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Study designs for evaluating the effects of healthcare interventions

Comparison between interventions Systematically

collected data

Multiple measurements before and after

the intervention

Intervention data registered prior to outcome More than one

group studied

Interventions assigned by investigators

Interventions assigned randomly

Interventions assigned to

individuals

Randomised trial

Retrospective case-control study

Opinion paper

Prospective case-control study

Non-comparative study (e.g. Case series)

Groups defined by interventions

Cohort design Controlled before-after study

Both interventions

prospective

Prospective cohort study

Experimental intervention prospective

Non-concurrent cohort study

Retrospective cohort study

Before-after study

Interrupted time series study

Repeated measures study Repeated

measures in the same individuals

Non-randomised trial

Cluster randomised trial

Yes

No

No No No

No No

No

No No

Yes

Yes Yes

Yes

No

No Yes

(Shaded boxes are study designs that should be considered for inclusion in EPOC reviews.)

No

https://epoc.cochrane.org/sites/e poc.cochrane.org/files/public/uplo ads/EPOC%20Study%20Designs%

20About.pdf

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If possible, include all languages

Reduces publication bias

Requires resources

INCLUSION/EXCLUSION: LANGUAGE

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 Intervention Review Question

 Which of the many available microbial products improve healing in patients with chronic wounds

INCLUSION/EXCLUSION: EXAMPLE

Component Inclusion Criteria Exclusion Criteria

Population Adults with chronic wounds Other wounds Intervention • Systemic preparations

• Topical preparations Comparison • Placebo

• No antimicrobial

• Different antibiotics

Lack of comparison

Outcome Wound healing Wound healing not assessed Study Design Randomized trial Non-randomized trial

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INCLUSION/EXCLUSION: EXAMPLE

Intervention Review Question

 Are knowledge translation (KT) interventions

directed to nurses in tertiary care are effective for improving EBP knowledge, skills, behaviours, and, as a result, patient outcomes

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Inclusion/Exclusion Criteria

IN-CLASS ACTIVIT Y

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SEARCH STRATEGY

Identify search terms

Selection of relevant databases

Retrieval of citations from searches

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As extensive as possible

Published

Unpublished

Aim for

comprehensiveness (high sensitivity)

Accept

large number of relevant results (low precision)

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RESOURCES FOR SEARCHING

Internet access

Ability to obtain articles through inter-library loan

“Manpower” to retrieve hardcopy of articles and scan

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e.g. EndNote, Reference Manager, RefWorks

Download

full record citation

key fields

Abstracts

Identifier

 Accession number/unique identifier (PMID)

 Digital object identifier (DOI)

 Clinical trial number

Index terms/thesaurus terms/keywords

Language

Comments/corrections/errata/retrations/updates

BIBLIOGRAPHIC SOFT WARE

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SEARCH TERMS

No agreed upon standard

Compile list of terms

Previous searches

Key words

Identify synonyms for the terms

Related terms

e.g. brain vs. head

Account for spelling variation

e.g. pediatric vs paediatric

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COMBINING SEARCH TERMS

“or” ^“and” “or”

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GENERAL SEARCH TIPS

Quotations and Parentheses

(“leg ulcer” or “varicose ulcer”) and chronic

Asterisk [*]

e.g. nurs*

searches for nurses, nursing, nurse

Wildcard [?]

e.g wom?n

searches for woman or women

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MeSH

“medical subject heading”

Controlled terms used in MEDLINE to index citations

Cochrane Handbook

Other databases use “MeSH-like”

terms

Thesaurus or Index Structure

INDEXING OF CONTROLLED TERMS

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OVID MEDLINE TIPS

$

 Truncation

 antibiotic$ will search for

 antibiotics in general

 different types of antibiotics, e.g. antibiotics,

aminoglycosides;

antiobiotics, lactam

Adj

 Proximity and adjacency searching

 chronic adj wounds$ will search for the

 words next to each other

.tw

 Textword search

 skin adj ulcer.tw will search

 for these adjacent

textwords in the title or abstracts

/

 Medical subject heading (MeSH) search

 diabetic foot/ will search

 for MeSH in indesing terms

Khan, K., Kunz, R., Kleijnen, J., Antes, G. Systematic reviews to support evidence-based medicine, 2nd edition

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Which of the many available microbial products improve healing in patients with chronic wounds

 Are knowledge translation (KT) interventions directed to nurses in tertiary care are effective for improving EBP knowledge, skills, behaviours, and, as a result, patient outcomes

SEARCH TERMS: EXAMPLES

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Search Terms

IN-CLASS ACTIVIT Y

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Bibliographic databases

Journals and other non-bibliographic database sources

Unpublished and ongoing studies

SOURCES TO SEARCH

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Subject specific

additional International/National/

Regional databases

Trial Registries

Citation Indexes

Dissertation and theses databases

Grey literature

BIBLIOGRAPHIC DATABASES

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Handsearching

Electronic Journals

http://www.evidencebasednursing.it/riv iste.htm

Conference Proceedings

http://www.evidencebasednursing.it/as socia.htm

Reference Lists

Experts

JOURNALS/NON-BIBLIOGRAPHIC DATABASE SOURCES

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

Trial registers

http://www.alltrials.net/

UNPUBLISHED AND ONGOING STUDIES

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Which of the many available microbial products improve healing in patients with chronic wounds

 Are knowledge translation (KT) interventions directed to nurses in tertiary care are effective for improving EBP knowledge, skills, behaviours, and, as a result, patient outcomes

WHERE TO SEARCH: EXAMPLES

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Where to Search

IN-CLASS ACTIVIT Y

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Databases searched

Dates of the last search for each database

Period searched

Grey literature sources.

Individuals or organizations contacted

Journals searched

Electronically and/or handsearch

Conference proceedings

Other sources searched, e.g.

Reference lists

Internet

DOCUMENTING SEARCH

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

Number of records retrieved

PRISMA Flow Diagram

Full search strategies for each

database

Appendix

Additional File

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SYSTEMATIC REVIEW METHODS