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in Evidence-biased Medicine ผศ.นพ. อนิรธ ุ ภัทรากาญจน์ Aims of Literature Search • To solve clinical problems (EBM) • To search for existing knowledge in order to conduct a research • To update knowledge “5A” of Evidence-Based Practice ASSESS problem ASK the right question ACQUIRE search for the best available evidence APPRAISE the evidence ASSESS Decision making APPLY Professional experience Pathophysiology Pharmacology Psychology Organizational issues Costs Politics etc General Search Strategy Search the best available database Define relevant, searchable terms Design search strategy No Relevant results? Yes Poor Summarize & Appraise the evidence GOOD Apply the evidence Well-built Clinical Question : PICO •P •I •C •O • Patients or population Intervention Comparison Outcome Type of question – Therapy, etiology, prognosis, diagnosis, etc. • Study design – Descriptive, case-control, RCT, etc. Example อยากทราบว่ าในผู้ป่วยเด็กที่เป็ น diabetic nephropathy จะมีอตั รา การเกิด ESRD ต่ างกันหรือไม่ ระหว่ างกลุ่มที่ได้ รับ ACEI ร่ วมกับ ARB เปรียบเทียบกับกลุ่มที่ได้ รับ ACEI เพียงอย่ างเดียว Formulate the question • Patients : children with diabetic nephropathy • Intervention : ACEI+ARB • Comparison : ACEI • Outcome : ESRD • Question : therapy • Design : systematic review, RCT Tools • Hardware – A computer with (good & fast) online access • LAN, MODEM (ADSL, cable) • Software – Web browser • Internet Explorer, FireFox, Opera – Adobe Reader® (latest version from adobe.com) – Reference management softwares • • EndNote®, ProCite®, Reference Manager® Electronic databases – On-line – Off-li Medical Clinical Evidence Sources • • • • • • • Expert • References Standard textbooks • References of the references Teaching documents • Index books Meeting presentation Science citation index Proceedings of presentation Index medicus (1879) Thesis Excerpta medica (1948) Current contents • Electronic databases Search Exhaustively • • • • • • • Electronic databases Printed journals, hand-search Unpublished articles Expert seeking Pharmaceutical companies data Grey literature General internet search engines: google, yahoo, msn, altavista, itools Internet Search Engines • General - Google - Yahoo - MSN - Live - Altavista - Excite - HotBot - Lycos - Go.com - Ask.com • Special search engine • - Clusty.com - Kartoo.net Metasearch engines - Gahooyoogle.com (search Yahoo, Google,all at once) - Arrowsearch.net - Copernic Agent Electronic Databases • Bibliographic databases • Medline Embase Scopus Science Citation Index LILACS Open access databases Grey literature databases Web search engines Google Scholar Scirus Bibliographic Database • Medline About 5,000 journals Free access via PubMed http://www.ncbi.nlm.nih.gov/pubmed/ Now include “Oldmedline” Oldest article in 1865 Trans Am Ophthalmol Soc PubMed Central (http://www.ncbi.nlm.nih.gov/pmc/) Free full-text Mostly articles in English from North American region Bibliographic Databases (Thai) • Siriraj: Thai Medical Index (http://www.medlib.si.mahidol.ac.th/) • Chula: Thai Index Medicus (http://www.library.md.chula.ac.th/) • Other Thai databases – ศูนย์บริการความรูท้ างวิทยาศาสตร์และเทคโนโลยี (http://www.stks.or.th/web/) – ห้องสมุดงานวิจยั สานักงานคณะกรรมการวิจยั แห่งชาติ (http://www.riclib.nrct.go.th/) Bibliographic Databases (Thai) • Thai journal pointer – Journal Link (www.journallink.or.th) • Thai journal citation index center (TCI) (www.kmutt.ac.th/jif/public_html/) Pre-filtered Clinical Resources • Cochrane library – Online access: http://www.thecochranelibrary.com/view/0/index.html – Offline access: CD updated quarterly • ACP Journal Club (previous Best Evidence) – www.acpjc.org • Clinical Evidence – www.clinicalevidence.com • Evidence-based Medicine (EBM Online) – http://ebm.bmj.com/ Pre-filtered Clinical Resources • UpToDate – www.uptodate.com – CD updated every 4 months Multidisciplinary Clinical Resources • Ovid.com • MDConsult.com – Full-text of “Clinics of North America” Journals – Full-text of “Year Books” – Not all have pdf files Electronic Text Books • Harrison Online – www.harrisonsonline.com – www.harrisonsmed.com (store) What is PubMed? • A web-based retrieval system developed by NCBI (a part of Entrez retrieval system) • Free version of MEDLINE on the web NIH National Institutes of Health NLM National Library of Medicine NCBI National Center for Biotechnology Information PubMed Database • A database of bibliographic information drawn primarily from the life sciences literature • PubMed contains links to – Full-text articles at participating publishers' Web sites – Other third party sites such as libraries and sequencing centers • All citations in MEDLINE are assigned MeSH Terms and Publication Types from NLM's controlled vocabulary. What Does MEDLINE Cover? • Not only medicine – medicine – nursing – dentistry – veterinary medicine – health care system – preclinical sciences e.g., molecular biology How Big is MEDLINE? • > 5,000 biomedical journals • > 16 million citations back to 1865 • Published in the U.S. and 70 other countries. • Coverage is worldwide, but most records are from English-language sources or have English abstracts • MEDLINE contains citations, not full-text articles (PubMed provides links to full-text) A basic search 1. Identify the key concepts for your search. Example: Find citations about bronchodilators for treating asthma in children. The key concepts are bronchodilators, asthma and children 2. Enter terms into the search box. 3. Press the Enter key or click Search. Combining search terms with Boolean operators • AND retrieves results that include all the search terms. • OR retrieves results that include at least one of the search terms. • NOT excludes the retrieval of terms from your search. Combining search terms with Boolean operators • Examples – Find citations on DNA that were authored by Dr. Crick in 1993: dna [mh] AND crick [au] AND 1993 [dp] – Find citations on the effects of heat or humidity on multiple sclerosis: (heat OR humidity) AND multiple sclerosis – Find citations about arthritis excluding the Publication Type Letter: arthritis NOT letter [pt] Automatic term mapping (ATM) • Untagged terms that are entered in the search box are matched (in this order) against – MeSH (Medical Subject Headings) translation table – Journals translation table – Full Author translation table – Author index – Full Investigator (Collaborator) translation table – Investigator (Collaborator) index Automatic term mapping (ATM) • To bypass ATM, using the following formats: – Enclose the phrase in double quotes: “kidney allograft” – Use a search tag: kidney allograft[tw] – Use a hyphen: first-line – Truncate: kidney allograft* Truncating search terms • Example flavor* Finds terms that begin with the root term flavor, such as flavored, flavorful, flavoring, etc. MeSH • NLM's controlled vocabulary thesaurus. • Terms naming descriptors in a hierarchical structure that permits searching at various levels of specificity. Example of MeSH Example of MeSH Example of MeSH Search Field Descriptions and Tags Search Field Descriptions and Tags • Example – Search for articles about influenza published in the New England Journal of Medicine – influenza [mh] AND n engl j med [ta] Searching by author • Enter the author’s name in the format of last name followed by initials. Omit punctuation. – Examples smith ja jones k • If only the author's last name is entered, tag the name with the author search field [au] • Full author names may be searched for citations published from 2002 Searching by journal title • Enter in the search box one of the following: – full journal title (e.g., molecular biology of the cell) – title abbreviation (e.g., mol biol cell) • To find full journal names, use the Journals database • Use the Single Citation Matcher (http://www.ncbi.nlm.nih.gov/corehtml/query/static/citmatch.html ) Limits • by dates, type of article, languages, species, gender, subsets, ages, text options, and specific search fields. http://www.ncbi.nlm.nih.gov/pubmed/ Combining searches using History • Previous searches can be combined or used in subsequent searches http://www.ncbi.nlm.nih.gov/pubmed/ Summary Display Abstract Display Medline Display เพื่อบันทึก file ในรูปแบบของ medline ในกรณี ที่ต้องการทางานส่วน reference manager เพื่อบันทึก article ที่คดั เลือกไว้ เก็บรวบรวมในส่วน clipboard Search Strategy Tips • Identify the key concepts. • Determine alternative terms for these concepts, if needed. • Refine your search to dates, study groups, etc., as appropriate. • Practice helps. Strategies and styles will differ according to personal choice and professional discipline. • เด็กชายอายุ 5 เดือน มีประวัติ UTI พัฒนาการปกติ ตรวจร่างกายพบ เพียง phimosis ผล imaging studies เป็ นปกติ มารดาได้รบั คาแนะนา ให้ใช้ steroid cream ทาหนังหุม้ ปลายให้ทารก จึงมาขอคาแนะนาจาก ท่าน • Patients : infants with phimosis • Intervention : circumcision • Comparison : no circumcision • Outcome : Urinary tract infection • Question : therapy • Design : systematic review, RCT • Patients : infants with phimosis • Intervention : steroid • Comparison : no intervention • Outcome : retractable prepuce • Question : therapy • Design : systematic review, RCT