Literature Searching Pawin Numthavaj M.D. Section for Clinical Epidemiology and Biostatistics Faculty of Medicine, Ramathibodi Hospital, Mahidol University Bangkok, Thailand www.ceb-rama.org
Literature searching Needed for every study before study conduction Provide the knowledge of Gap of information Why should you do your research Conducting a systematic review recommended
Study Identification Process Select Database(s) to Use Develop Search Strategy Modify Search Strategy Searching Explore Results from Searching Export into Reference Manager
Database Journal Articles Databases MEDLINE EMBASE SCOPUS Cochrane databases DARE (Database of Abstracts of Reviews of Effects) Web of Science CINAHL PsycINFO Etc. Grey Literature Organization reports Governmental reports Conference Proceedings Dissertation & Theses Web
Multiple Databases MEDLINE CINAHL EMBASE
Research Question P I C O Patient Intervention Comparison Outcome
P AND I AND C AND O Bell Palsy Idiopathic Facial Palsy Antiviral Steroid Steroid Recovery Rate House-Brackmann Scale Sunnybrook Scale Acyclovir Valacyclovir Prednisolone Methylprednisolone Prednisolone Methylprednisolone
Group Your Question into Terms Terms #1 Subject Headings Text words Terms #2 Subject Headings Text words Terms #3 Subject Headings Text words Antiviral Antiviral agents Antivirus, Antiviral drug, Steroid Steroids Steroid, Prednisolone, Bell Palsy Bell Palsy Bell Palsy, Idiopathic facial paralysis,
Combination of Search Terms Use AND between domains (P/I/C/O) Use OR inside domains for similar terms or terms that have several synonyms Try to use keyword searching
Subject Headings Database MEDLINE EMBASE CINAHL Cochrane Library PsycINFO SCOPUS Web of Science Subject Headings MeSH EMTREE CINAHL Headings MESH Thesaurus of Psychological Index Terms N/A N/A
Search Engine and Database Search Engine PubMed Ovid Scopus Database(s) MEDLINE MEDLINE, EMBASE, SCOPUS
PubMed Searching
PubMed Free search engine Comprises of MEDLINE database Maintain by US National Library of Medicine, National Institutes of Health First released in 1996 Accessed from http://www.pubmed.gov
MEDLINE 1946 to present material 5,600 journals in 39 languages 2,000-4,000 references added each day Biomedicine and health
Frequently Used Functions in PubMed 1. MESH 2. Search Operators 3. Limits 4. Clipboard 5. Save searches 6. Advanced search 7. Citation matcher 8. Clinical Queries 9. Retrieval of full text paper
MESH Medical Subject Heading Keyword system in Medline
Search Operators Truncated search term (wildcards) flavor* = flavoring + flavored + flavors synerchi* = synerchiae + synerchia Combining search terms AND OR NOT ( )
Limits Filter unwanted results Age: infants, adults, Article types: original studies, RCTs, Metaanalysis, Article language Human/animal Recently published
Clipboard Stored items for later review Max 500 items 8 hours before deleted Send to collection instead if you want to permanently stored (Need My NCBI account)
Saved search Save for later updates Useful when you re doing systematic review Can also automatically e-mail updates
Advanced Search Search in command linebased Useful for complex searches Use # for referring to previous searches Operators: AND, OR, NOT, and ()
Download History CSV File Open in Spreadsheet programs (Excel) For use in report of search strategy supplementary table
Export to EndNote
Export to EndNote Send To command File Choose MEDLINE In EndNote choose PubMed (NLM) Citation manager.nbib EndNote Limit 200 article maximum
Citation Matcher Locate an article when you know the author name / title / journal name / volume / pages http://www.ncbi.nlm.nih.gov/pubmed/citmatch or visit pubmed.gov and look for Single Citation Matcher
Example Try to find this article from PubMed
REFERENCE: "Itch Relief by Mirror Scratching. A Psychophysical Study," Christoph Helmchen, Carina Palzer, Thomas F. Münte, Silke Anders, Andreas Sprenger, PLoS ONE, vol. 8, no 12, December 26, 2013, e82756.
Clinical Queries Filter for specific area of question Etiology Diagnosis Therapy Prognosis Clinical Prediction Guides Systematic Review
Category therapy diagnosis etiology prognosis clinical prediction guides Optimized For Sensitive/ Specific sensitive/broad 99%/70% specific/narrow 93%/97% sensitive/broad 98%/74% PubMed Equivalent ((clinical[title/abstract] AND trial[title/abstract]) OR clinical trials[mesh Terms] OR clinical trial[publication Type] OR random*[title/abstract] OR random allocation[mesh Terms] OR therapeutic use[mesh Subheading]) (randomized controlled trial[publication Type] OR (randomized[title/abstract] AND controlled[title/abstract] AND trial[title/abstract])) (sensitiv*[title/abstract] OR sensitivity and specificity[mesh Terms] OR diagnos*[title/abstract] OR diagnosis[mesh:noexp] OR diagnostic * [MeSH:noexp] OR diagnosis,differential[mesh:noexp] OR diagnosis[subheading:noexp]) specific/narrow 64%/98% (specificity[title/abstract]) sensitive/broad 93%/63% specific/narrow 51%/95% sensitive/broad 90%/80% specific/narrow 52%/94% sensitive/broad 96%/79% (risk*[title/abstract] OR risk*[mesh:noexp] OR risk *[MeSH:noexp] OR cohort studies[mesh Terms] OR group*[text Word]) ((relative[title/abstract] AND risk*[title/abstract]) OR (relative risk[text Word]) OR risks[text Word] OR cohort studies[mesh:noexp] OR (cohort[title/abstract] AND stud*[title/abstract])) (incidence[mesh:noexp] OR mortality[mesh Terms] OR follow up studies[mesh:noexp] OR prognos*[text Word] OR predict*[text Word] OR course*[text Word]) (prognos*[title/abstract] OR (first[title/abstract] AND episode[title/abstract]) OR cohort[title/abstract]) (predict*[tiab] OR predictive value of tests[mh] OR scor*[tiab] OR observ*[tiab] OR observer variation[mh]) specific/narrow 54%/99% (validation[tiab] OR validate[tiab]