developing a search strategy for your systematic review
DESCRIPTION
This presentation was made to researchers in public health and nutrition at the Summer Institute for Systematic Reviews in Nutrition for Global Policy Making, a collaboration of WHO, Cochrane Collaboration and Cornell University's Division of Nutritional Sciences.TRANSCRIPT
Developing your SR search strategySARAH YOUNG
HEALTH SCIENCE AND POLICY LIBRARIAN
Today’s presentation
Access to library resourcesDeveloping your search strategyReporting of ongoing unpublished trialsUsing library services
A guide to library resources
http://guides.library.cornell.edu/WHO
Access to resources: The catalog
https://www.library.cornell.edu/
Access to full text
Developing your search strategy
Example: MalnutritionUse both indexing terms and free-text
“Malnutrition"[MeSH] OR “malnutrition” OR “undernutrition" OR “under-nutrition” OR “nutritional deficiency” OR “undernourishment”
Why use free-text AND indexing terms?
Indexing quality varies by databaseSome articles have not yet been indexedNo abstract includedNon-English material
Standardized Index Terms
HIV"human immuno-deficiency virus" n=199
"HIV"[Mesh] n=80480
Combine standardized terms with natural languageHIV"human immuno-deficiency virus" n=199
"HIV"[Mesh] n=80480
"HIV"[Mesh] OR "human immuno-deficiency virus" n=80640
We added 160 articles by including the free-text term in the MeSH term search
Search strategy with harvested terms HIV Infections[MeSH] OR HIV[MeSH] OR hiv[tw] OR hiv-1[tw] OR hiv-2[tw] OR human immunodeficiency virus[tw] OR human immunedeficiency virus[tw] OR human immuno-deficiency virus[tw] OR human immune-deficiency virus[tw]
n= 315017
Term harvesting
Synonyms in standard index entries Titles and abstracts of key articles Dictionaries and Thesauri
Example: preterm infant
Putting together a search strategy
High sensitivity (low precision) Minimize bias Reproducible (documentation)
Putting together a search strategy
Example:
Micronutrient supplementation in pregnant women with HIV infection The Cochrane Collaboration Siegfried N, Irlam JH, Visser ME, and Rollins NN 2012
Putting together a search strategy
Objective:
To assess whether micronutrient supplements are effective and safe in reducing mortality and morbidity in pregnant women with HIV infection.
HIV
Type of study: RCT
Micronutrients
Micronutrients (cont.)
Micronutrients (combined)
Type of study: RCT
Search tips: Use the syntax appropriate to the database
Search tips: Use the syntax appropriate to the database
Identify text terms
Term harvest for synonyms
Control for spelling variation and use
truncation
Identify indexing terms
Decide to explode or focus indexing terms
Combine all search terms
logically
Customize syntax for other
databases
Perform test searches
Perform test searches
Choosing databases
Choosing databasesSearched for reports of maternal mortality and morbidity across various study designs
MEDLINE, Popline, EMBASE, CINAHL, CAB Abstracts, Econlit, Sociofile, LILACS, BIOSIS and PAIS International
2580 citations included
Choosing databases
MEDLINE EMBASE BIOSIS POPLINE0
20
40
60
80
100
62
44
1712
Percent of Total Citations Identified
A guide to library resources
http://guides.library.cornell.edu/WHO
Outside of the published literature
Publication bias
Other sources: Unpublished clinical trials WHO International Clinical Trials Registry Platform (ICTRP) http://www.who.int/ictrp/en/
metaRegister of Controlled Trials (mRCT) http://www.controlled-trials.com/mrct/
Other sources: Grey Literature
“…literature that is not formally published in sources such as books or journal articles.”
Cochrane Handbook for Systematic Reviews of Interventions
Other sources: Grey Literature
"That which is produced on all levels of government, academics, business and industry in print and electronic formats, but which is not controlled by commercial publishers.“
The Fourth International Conference on Grey Literature, Washington, DC
A guide to library resources
http://guides.library.cornell.edu/WHO
Finding Mann Library
Room to work
Available library services
Access to full text Search strategy development
Using the databases Citation management
Questions about Research4Life
Help with your research
[email protected] Office hours:
2-4 pm (except tomorrow) Services and Collections offices, 1st floor of Mann
References Betran, A.P. et al. (2005). “Effectiveness of different databases in identifying studies for systematic reviews: experience from the WHO systematic review of maternal morbidity and mortality”. BMC Medical Research Methodology, 5:6.
Fowler, S. (2013). “Library Resources for Systematic Reviews”. Presentation available from http://www.slideshare.net/referencegirl/sys-revs-colditz.
Higgins, J.P.T. and Green, S. (eds.) (2011). Cochrane Handbook for Systematic Reviews of Interventions, Version 5.1.0, available from http://handbook.cochrane.org/.
Siegfried, N. et al. (2012). “Micronutrient supplementation in pregnant women with HIV infection (Review)”. The Cochrane Library, Issue 3.