Search of the literature

Transcription

1 Disclaimer: The contents of this presentation are the views of the author and do not necessarily represent an official position of the European Commission. European Union, 2013 Search of the literature Theodora Mouratidou and Carlos Martin Saborido Public Health Policy Support Unit Institute for Health and Consumer Protection (JRC-IHCP) GRADE Workshop: Agenda 9:00-10:15 Introduction. Guideline development process and the GRADE approach 10:15-11:00 Types of questions. Framing a question: PICO question. Exercise 11:00-11:15 Coffee 11:15-12:00 Choosing outcomes. Relative importance of outcomes. Exercise 12:00-12:45 Study designs. Exercise 12:45-13:30 Lunch 13:30-14:30 Search of the literature. Exercise 14:30-15:00 Determinants of quality of evidence: What can lower the evidence? (I) 15:00-15:15 Coffee 15:15-17:00 Determinants of quality of evidence: What can lower the evidence? (II) Exercise 9:00-11:15 Determinants of quality of evidence: What can lower the evidence? (III) Determinants of quality of evidence: What can upgrade evidence? 11:15-11:30 Coffee 11:30-13:00 Going from the evidence to the recommendation. Exercise 13:00-13:45 Lunch 13:45-16:00 Using the Guideline Development Tool (GDT) software. Exercise 2 GRADE Workshop Feedback Ispra and December conclusions 2013 Outline Searching where? a. Introduction b. Search evidence in Medline c. Search evidence beyond Medline d. Other sources of evidence e. Practical exercise Databases used will depend on a number of factors including the research question, the study design of studies to be included as well as on your resources! RCTs: Medline, Central, EMBASE Systematic Reviews: Medline, CDSR, EMBASE, DARE Health Technology Assessment: HTA database + websites Guidelines: Medline, NGC, GIN, websites Diagnostic tests: Medion Nursing aspects: Cinahl 3 GRADE Workshop Ispra December GRADE Workshop Ispra December 2013 Medline Searching MEDLINE PubMed Central (PMC) is the National Library of Medicine's digital archive of full-text journal literature > 6000 journals, 20 millions articles Free of charge 65% RCTs US-based, biased towards english (91%) How is the the MeSH used Search strategy Managing results Saving search strategies Getting the articles.a specific set of terms used to describe each article 5 GRADE Workshop Ispra December GRADE Workshop Ispra December

2 Search strategy Medical Subject Headings (MeSH) Balance between sensitivity (attempts to retrieve all relevant documents by using a broad search) and specificity (attempts to retrieve only relevant documents in a small precise search). A happy medium is desirable! Boolean logic (allow you to broaden or focus your search results) AND OR NOT Articles are indexed using a powerful vocabulary called MeSH The MeSH Database provides the option of identifying appropriate MeSH terms for searches Represent concepts found in the biomedical literature arranged in a hierarchical manner called the MeSH Tree Structure (16 main branches) > MeSH descriptors > entry terms MeSH terms are "exploded" automatically to retrieve citations that carry the specified MeSH (sub) heading and also retrieve citations that carry any of the more specific MeSH (sub) headings indented beneath it in the Tree structure. x AND (y OR z) will retrieve records that contain the term x, as well as one or both of the terms y OR z 7 GRADE Workshop Ispra December GRADE Workshop Ispra December GRADE Workshop Ispra December GRADE Workshop Ispra December 2013 MeSH Medline indexers assign the most specific MeSH heading(s) appropriate to describe the main concepts discussed (or the closest one) Generally 5 to 15 MeSH MeSH terms reflecting the major points of the article are marked with an asterisk (*) Information the indexer provides includes: topic of article age group of population studied human vs. animal studies type of article (e.g., review article) MeSH database The MeSH Database allows you to: Locate and select MeSH terms, (Headings, Subheadings, & Publication Types); Supplementary Concept terms (Substance Names) and Pharmacological Action terms See the definition and other helpful information for a MeSH term Build a PubMed search strategy Display MeSH terms in the hierarchy Limit MeSH terms to a major concept for a search Attach subheadings for a search Link to the NLM MeSH Section's MeSH Browser Not all databases allow MeSH searches! And searching with MeSH headings will exclude in process and publisher-supplied citations, as they are not indexed with MeSH 11 GRADE Workshop Ispra December GRADE Workshop Ispra December

3 Phrase Searching PubMed automatically searches for phrases during Automatic Term Mapping (ATM)-process to find a match to unqualified terms that are entered into the query box If you want to force a phrase search, you can do so by: Enclosing the phrase in double quotes: "fecal transplant" Note: The absence of a search tag indicates the search should be conducted in All Fields Using quotes, search tags, hyphenation or truncation instructs PubMed to bypass ATM. Instead PubMed looks for the phrase in its Index of searchable terms. If the phrase is in the Index, PubMed will retrieve citations that contain the phrase PubMed may fail to find a phrase because it is not in the Index Your phrase may actually appear in citation and abstract data, but may not be in the Index. If this is the case, the double quotes are ignored and the phrase is processed using Automatic Term Mapping Entering the phrase with a search tag: robotic surgery [tw] Hyphenating: first-line Truncating: citizen jur* GRADE Workshop Ispra December GRADE Workshop Ispra December 2013 Truncation terms (*,?) Truncation: search method in which symbols are used in place of letters or words to broaden search - Asterisk (*) e.g. Medic*: medical or medicine - Question mark(?) e.g. Analys?s: retrieve Analysis y Analyses e.g. Meta?analysis: retrieve metaanalysis AND metaanalysis Truncation turns off mapping on both unqualified or qualified terms. PubMed Search History Is available on the Advanced Search page showing your search strategies and number of items found for each search Can hold a maximum of 100 search statements The History screen displays: Your search query Most recent 5 searches are displayed The time of the search The number of citations in your search results Search statement numbers menu for combining searches The search history is deleted after 8 hours of inactivity If a search is repeated, its original number is moved to the top 15 GRADE Workshop Ispra December GRADE Workshop Ispra December 2013 Managing results My NCBI(personal account; password required) Getting the articles Links to full text resources from PubMed are available through a service called LinkOut Searches: save search strategies to get updates, including automatic updates Collections: save search results My Bibliography: collect citations for your publications 17 GRADE Workshop Ispra December GRADE Workshop Ispra December

4 Disclaimer: The contents of this presentation are the views of the author and do not necessarily represent an official position of the European Commission. JRC xxxxx European Union, 2013 EMBASE Cochrane Library Europe-based > 24 million references +/ journals (>2000 non-medline) Pharmacological journals! EMTREE contains all MeSH terms as used in Medline (many as synonyms) > controlled descriptors (preferred terms) > synonyms (i.e. guides to preferred terms) Cochrane Database of Systematic Reviews, CDSR Database of Abstracts of Reviews of Effects, DARE Cochrane Central Register of Controlled Trials =CENTRAL Cochrane Methodology Register, CMR Health Technology Assessment Database NHS Economic Evaluation Database 19 GRADE Workshop Ispra December GRADE Workshop Ispra December 2013 Other databases Specific public health sources Centre for Reviews and Dissemination, University of York: PEDro: Cinahl: Medion: PsycInfo: National Guideline Clearinghouse: Guidelines International Network: SUMSearch: TRIP Database: Citation Indexes (e.g. ISI Web of Knowledge) Public Health Interventions Cost Effectiveness Database (PHICED): Database of Promoting Health Effectiveness Reviews (DoPHER): Canadian Institutes of Health Research (CIHR): Public Health + (National Collaborating Centre for Methods and Tools, NCCMT): And others 21 GRADE Workshop Ispra December GRADE Workshop Ispra December 2013 Links Any questions? Next: Exercise 23 GRADE Workshop Ispra December

5 Take home example 25 GRADE Workshop Ispra December GRADE Workshop Ispra December GRADE Workshop Ispra December GRADE Workshop Ispra December GRADE Workshop Ispra December

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