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EPIB-675: Special Topic 6: Knowledge Synthesis - Library Guide

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Has your review or synthesis already been done?

Has your review or synthesis already been done?

Finding systematic reviews or syntheses on your topic

Once you have a reasonably well defined research question, it is important to make sure your project has not already been recently and successfully undertaken. This means it’s important to find out if there are other research syntheses (including systematic reviews) that have been published or that are in the process of being published on your topic.

If you are submitting your systematic review for funding, for example, you may want to make a good case that your review or synthesis is needed and not duplicating work that has already been successfully and recently completed—or that is in the process of being completed. It is also important to note that what is considered “recent” will depend on your discipline and the topic.

Even if you do find another review or synthesis on your topic, it may be sufficiently out of date or you may find other defendable reasons to perform it again. In addition, looking at other research syntheses published around your topic may also help you refocus your question or redirect your research toward other gaps in the literature.

These tips may not cover every possible type of research synthesis but they provide a decent start.

To find other reviews or syntheses:

To find other reviews or syntheses:

Search databases specifically focused on systematic reviews using a very broad search strategy, databases such as:

The Cochrane Library (including systematic reviews of interventions, diagnostic studies, prognostic studies, and more) is an excellent place to start.

By default, the Cochrane Library will search “Cochrane Reviews” (Cochrane Database of Systematic Reviews, aka CDSR) as well as “Other Reviews,” aka DARE (Database of Abstracts of Reviews of Effects), although the latter is no longer being updated as of 2015. The Cochrane Library also searches “Technology Assessments” (Health Technology Assessment Database), and “Economic Evaluations” (NHS Economic Evaluation Database). You can ignore the results which show up in the Trials sub-database when looking for systematic reviews: They are records of controlled trials and may make the result set appear a lot bigger than it really is, if you’re focusing on reviews.

The example to the right shows the number of results for a simple search of the term statin* in the title, abstract, or keywords.

In addition, you can perform a sufficiently developed search strategy on MEDLINE via PubMed (be as broad in your search as is reasonable) and then use the “Article types” filter for “Systematic Reviews” to see if other reviews have been published on your topic. Systematic reviews found in PubMed and not included in The Cochrane Library may require more careful critical appraisal for quality assessment.

 

Alternative interface to PubMed: You can also search MEDLINE on the Ovid platform. Perform a sufficiently developed search strategy (be as broad in your search as is reasonable possible) and then use the “Additional limits” to filter to the Subject Subset called “Systematic Reviews” to see if other reviews have been published on your topic. Systematic reviews found in PubMed and not included in The Cochrane Library may require more careful critical appraisal for quality assessment.

To search for systematic reviews in Embase on Ovid, perform a reasonably developed search strategy (be as broad in your search as is reasonably possible) and then combine your search results with a systematic review filter developed for Embase on Ovid, e.g., filters available at https://sites.google.com/a/york.ac.uk/issg-search-filters-resource/filters-to-identify-systematic-reviews

Example of a filter used to find systematic reviews for BMJ Clinical Evidence (can be copied and pasted into the Embase search box then combined with the concepts of your research question):

(exp review/ or (literature adj3 review$).ti,ab. or exp meta analysis/ or exp "Systematic Review"/) and ((medline or medlars or embase or pubmed or cinahl or amed or psychlit or psyclit or psychinfo or psycinfo or scisearch or cochrane).ti,ab. or RETRACTED ARTICLE/) or (systematic$ adj2 (review$ or overview)).ti,ab. or (meta?anal$ or meta anal$ or meta-anal$ or metaanal$ or metanal$).ti,ab.

For a more complete list of databases you can search for existing syntheses, please see:

Database search tips for PubMed, Ovid, and Web of Science

Database search tips

 

PubMed (MEDLINE)

 

Ovid Online

 

Web of Science
Command Search

Subject headings

 

MeSH (Medical Subject Headings)

 

MEDLINE: MeSH
Embase: EMTREE

Avoid cross-searching databases so that you can take advantage of the subject headings, if applicable

NA (includes Keywords Plus, searched by default)


TS=("mycobacterium tuberculosis")

Searching subject headings

"MeSH term"[mesh]


Includes narrower terms by default
"Tuberculosis"[mesh]

exp subject heading/


"Explode" to include narrower terms
exp tuberculosis/

NA

 

Searching major subject headings

"MeSH term"[majr]

Retrieves records in which the MeSH concept is considered a central topic of the article

"Tuberculosis"[majr]

exp *subject heading/

Retrieves records in which the subject heading is considered a central topic of the article

exp *tuberculosis/

 

Searching title/abstract terms

 

term[tiab]


tb[tiab]

Includes author keywords

term.ti,ab.


tb.ti,ab.

Does not include author keywords

 

Searching title terms

 

term[ti]


obesity[ti]

term.ti.


obesity.ti.

TI=(term)


TI=(obesity)

Searching title/abstract/
entry terms

term[tw]


infliximab[tw]

term.mp.


infliximab.mp.

TS=(term)


TS=(infliximab)

Phrase searching

 

terms in phrase[tw] OR "terms in phrase"[tw]

NB: Do NOT use quotations around truncated phrases in PubMed as PubMed will then ignore the truncation symbol; PubMed will phrase search by default when the search field is specified after the phrase (except [all fields])


participatory research[tw]

terms in phrase.mp. OR "terms in phrase".mp.


participatory research.mp.

"terms in phrase"
TS=("participatory

research")

Truncation

 

terms in phrase*[tw]


rheumatoid nodule*[tw]

terms in phrase*.mp. OR terms in phrase$.mp.


rheumatoid nodule*.mp.

"terms in phrase*"
TS=("rheumatoid

nodule*")

Adjacency searching

(to search for a term within x terms from another term)

NA; AND terms together instead (or phrase search)


(patient[tw] AND outcome*[tw])

termA adjn termB


patient adj2 outcome*.mp.

NEAR/x (by default,

NEAR = NEAR/15)
TS=(brown NEAR "spider bite")

RCT search filters for MEDLINE on Ovid, EMBASE on Ovid, and PubMed

RCT search filters

PubMed hedge for RCTs, modified with addition of randomised[tiab]:

((randomized controlled trial[pt]) OR (controlled clinical trial[pt]) OR (randomized[tiab] OR randomised[tiab]) OR (placebo[tiab]) OR (drug therapy[sh]) OR (randomly[tiab]) OR (trial[tiab]) OR (groups[tiab])) NOT (animals[mh] NOT humans[mh])

Source:

http://handbook.cochrane.org/chapter_6/box_6_4_a_cochrane_hsss_2008_sensmax_pubmed.htm

 

MEDLINE on Ovid filter for RCTs, modified with addition of randomised.ab.

((randomized controlled trial or controlled clinical trial).pt. or randomized.ab. or randomised.ab. or placebo.ab. or drug therapy.fs. or randomly.ab. or trial.ab. or groups.ab.) not (exp animals/ not humans.sh.)

Source:

http://handbook.cochrane.org/chapter_6/box_6_4_c_cochrane_hsss_2008_sensmax_ovid.htm

 

Embase on Ovid filter for controlled trials:

crossover-procedure/ or double-blind procedure/ or randomized controlled trial/ or single-blind procedure/ or (random* or factorial* or crossover* or cross over* or placebo* or (doubl* adj blind*) or (singl* adj blind*) or assign* or allocat* or volunteer*).tw.

Source:

http://handbook.cochrane.org/chapter_6/6_3_2_2_what_is_in_the_cochrane_central_register_of_controlled.htm

(NB: does not remove animal studies as the MEDLINE version does)

EndNote: The Short Course (25 minutes)

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EndNote instructions @ McGill - Winter 2016

Exporting search results to EndNote - Steps

Exporting search results into EndNote

Note: This procedure helps you keep track of the information that will be needed to report the methods in the article and also to fill in the PRISMA flow diagram.

Have the right EndNote library open in the background before you begin exporting.

Note: We do not generally recommend using Safari as your browser during this process, although it can be used with some tweaking.

For more instructions on using EndNote or other software programs, please see the Citation Guide

The steps below cover Ovid MEDLINE, Embase Classic+Embase on Ovid, PubMed, and Web of Science.

Instructions for Ovid Online databases

Ovid MEDLINE

We often start by exporting records from Ovid MEDLINE, if applicable (you may have decided to only use PubMed to search MEDLINE; those instructions are below):

  1. In EndNote, create a new library for the records from the database in question (MEDLINE on Ovid) and have the library ready in the background
  2. From Ovid, export complete reference in groups of <= 1000 (e.g., 1-1000, 1001-2000), do this until all of your records are exported (Export > Export To: EndNote; Select Fields to Display: Complete Reference; Export Citations)

  1. Move batches of exported records to the library you created and check the final number of records in the library against the number of results listed in database
  2. OPTIONAL - Label the records themselves as having come from Ovid MEDLINE: In EndNote > Select all Ovid MEDLINE records > Tools > Change/Move/Copy Fields > Custom 1: Replace field with the text “MEDLINE on Ovid - yyyymmdd” for example
  3. From Ovid MEDLINE: Download the search history for your records: Export (1, 1-10) > choose Microsoft Word format, check off Search History, and save the Word document to your documentation folder, with a useful filename in a format like SearchTerms-yyyymmdd-MEDLINESearch-xRecords
    • Not including the records themselves, the search history can then be copied and pasted into an appendix of the article, to document the search strategy with exactness. Avoids transcription errors
  4. Save the search history to your personal Ovid account (free) and identify the search by database name and date; this greatly facilitates rerunning the search later if an update is needed
  5. Create a compressed version of the EndNote library for your records

Embase Classic+Embase

  1. In EndNote, create a new library for the records from the database in question (Embase Classic+Embase) and have the library ready in the background
  2. From Ovid, export complete reference in groups of <= 1000 (e.g., 1-1000, 1001-2000), do this until all of your records are exported (Export > Export To: EndNote; Select Fields to Display: Complete Reference; Export Citations)

  1. Move batches of exported records to the library you created and check the final number of records in the library against the number of results listed in database
  2. OPTIONAL: Label the records themselves as having come from Ovid Embase: In EndNote > Select all Ovid Embase records > Tools > Change/Move/Copy Fields > Custom 1: Replace field with the text “Embase on Ovid - yyyymmdd” for example
  3. From Ovid Embase: Download the search history for your records: Export (1, 1-10) > choose “Microsoft Word” format, check off “Search History”, and save the Word document to your documentation folder, with a useful filename in a format like SearchTerms-yyyymmdd-EmbaseSearch-xRecords
    • Not including the records themselves, the search history can then be copied and pasted into an appendix of the article, to document the search strategy with exactness. Avoids transcription errors
  4. Save the search history to your personal Ovid account (free) and identify the search by database and date; this greatly facilitates rerunning the search later if an update is needed
  5. Create a compressed version of the EndNote library for your records

PubMed

PubMed

  1. In EndNote, create a new library for the records from the database in question (PubMed) and have the library ready in the background
  2. From PubMed, Click on Send To > Choose Destination: File > Format: MEDLINE > Create File

  1. In Firefox: Open with EndNote

  1. If the file was saved to your computer instead of automatically being imported into EndNote, import the file into EndNote (In EndNote menu: File > Import > File and locate the saved PubMed file on your computer) > Select PubMed (NLM) filter (if not visible, click “Other Filters…” to find it)

 

  1. OPTIONAL – Label the records themselves as having come from PubMed: In EndNote > Select all PubMed records > Tools > Change/Move/Copy Fields > Custom 1: Replace field with “PubMed - yyyyymmdd”
  2. Save the search history for your records: From PubMed: Click Create alert under the search box or from the Advanced screen, click Download history to maintain the line-by-line version (if applicable). The search is saved in an agglomerated format but this is useful if you need to rerun the search later for an update
  3. Create a compressed version of the EndNote library for your records

Instructions for Web of Science

Web of Science

  1. In EndNote, create a new library for the records from the database in question (PubMed) and have the library ready in the background
  2. In Web of Science, Click on the arrow for the Save to EndNote online dropdown menu and select Save to EndNote desktop
  3. Export full records in groups of up to 500 (e.g., 1-500, 501-612)
  4. Move batches of exported records to the library you created and check the final number of records in the library against the number of results listed in database
  5. OPTIONAL – Label the records themselves as having come from Web of Science: In EndNote > Select all Web of Science records > Tools > Change/Move/Copy Fields > Custom 1: Replace field with “Web of Science - yyyyymmdd”
  6. From Web of Science: Copy and paste the search history into a Word document, adjust the formatting
  7. You can save the search history as a file on your computer and this file can later be uploaded to Web of Science to re-execute the search; this is useful later if an update is needed
  8. Create a compressed version of the EndNote library for your records

Create a backup, compressed EndNote library for your records

Create a backup, compressed EndNote library for your records

  • Before merging the libraries, create compressed libraries of each of the EndNote libraries from the individual database searches
  • Using the uncompressed versions of those libraries, bring all the records from your separate searches in to one EndNote library if you haven’t done so already: From EndNote menu, File > Import > File > locate individual .enl files; Import: EndNote library.

Create a new EndNote library for deduplication and backup after deduplicating

Create a new EndNote library for deduplication and backup after deduplicating

Removing duplicates

See slides or Bramer et al. paper in JMLA with instructions on deduplicating in EndNote.

Create a compressed library for backup after having removed all duplicates, with a filename like SearchTerms-yyyymmdd-Deduplicated—xRecords.enlx. This will be the library for screening.

Document, document, document

Document, document, document

Record the information (names of databases/platforms searched, database time coverage, date searched, number of records from each database before deduplicating, number of records after deduplicating, etc.) in separate sheet (Documenting-Your-Search-2016.docx).

For information on saving your search history in Ovid MEDLINE or Embase, please see the slides.

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