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What to expect?. Core modules. Introduction Finding out relevant literature General guidelines for literature appraisal Abstract and Introduction appraisal Methods and Results appraisal 1 - Patients and procedures
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What to expect? Core modules • Introduction • Finding out relevant literature • General guidelines for literature appraisal • Abstract and Introduction appraisal • Methods and Results appraisal 1 - Patients and procedures • Methods and Results appraisal 2 - Data collection/management and descriptive analysis • Methods and Results appraisal 3 - Inferential analysis • Discussion and Conclusions appraisal
Resources for finding the literature • Seniors, juniors, and colleagues • Textbooks • Medical journals • World wide web
What to choose? or … fast but tough? Simple and easy-going
1st step: framing the question • Population:who are the relevant patients? • Intervention or exposure:what are the management strategies we want to appraise or the relevant harmful exposure we want to study? • Outcome:what are the patient-relevant consequences of the exposure in which we are interested?
2nd step: determining question type • Therapy:determining the effect of different treatments on improving patient function and avoiding adverse events • Harm:ascertaining the effects of potentially harmful agents on patient function, morbidity, and mortality • Diagnosis:establishing the power of an intervention to differentiate between those with and those without a target condition or disease • Prognosis:estimating the future course of a patient’s disease
1st step: example • All-purpose question:are coronary drug-eluting stents beneficial? • Improved (searchable) question: • Population: patients with acute or chronic coronary artery disease undergoing percutaneous revascularization • Intervention: coronary stents eluting anti-proliferative drugs • Outcome: cardiac death, non-fatal myocardial infarction, or ischemia-driven target vessel revascularization
2nd step: example • Therapy:which coronary device is more effective and safe? • Harm:what is the risk of stent thrombosis with drug-eluting stents? • Diagnosis:can I recognize which angiographically-intermediate lesions are functionally (ie, clinically) significant? • Prognosis:can I predict which patients are more likely to develop restenosis if treated with a bare-metal stent?
WWW resources • BioMedCentral: www.biomedcentral.com • Clinical Trial Results: www.clinicaltrialresults.org/ • DARE: www.york.ac.uk/inst/crd/crddatabases.htm • EMBASE: www.embase.com • Google scholar: scholar.google.com • Medscape: www.medscape.com • meta Register of Controlled Trials (mRCT):www.controlled-trials.com/mrct/ • PubMed: www.pubmed.gov • The Cochrane Library: www.cochrane.org • UpToDate: www.uptodate.com • WebMD: www.webmed.com • Web of Science: isiknowledge.com
WWW resources • BioMedCentral: www.biomedcentral.com • Clinical Trial Results: www.clinicaltrialresults.org/ • DARE: www.york.ac.uk/inst/crd/crddatabases.htm • EMBASE: www.embase.com • Google scholar: scholar.google.com • Medscape: www.medscape.com • meta Register of Controlled Trials (mRCT):www.controlled-trials.com/mrct/ • PubMed: www.pubmed.gov • The Cochrane Library: www.cochrane.org • UpToDate: www.uptodate.com • WebMD: www.webmed.com • Web of Science: isiknowledge.com
BioMedCentral • BioMedCentral is provided by a private UK company (the same that provides mRCT) • It mostly contains open access journals or conference proceedings • It may be a useful and cheap (it’s free!) starting point, but to date its content is limited • In the future however it should vastly expand
Clinical Trial Results • CTR is provided for free by C.M. Gibson (the inventor of the TIMI frame count and TIMI myocardial perfusion grade) • It contains pre-publication data from recent clinical trials • However, it is not comprehensive and its scope largely reflects the interests of its developer (ie acute coronary syndromes)
DARE • The Database of Abstracts of Reviews of Effectiveness is provided for free by the University of York • It contains titles and abstracts of systematic reviews of effectiveness • Each item contained (ie systematic reviews) is a very good starting point to get info on a topic • However, some hits are obsolete and no papers on prognosis, diagnosis, or pathophysiology are included to date
EMBASE • EMBASE is a comprehensive archiving site, provided for a fee by Elsevier • Its scope is similar but greater and largely non-overlapping with MEDLINE/PubMed • It may be useful for sophisticated researchers and systematic reviewers • However, it’s expensive and rarely needed, as most important papers will be already in MEDLINE/ PubMed
MEDSCAPE • A freely surfable website providing disparate content, owned by the WebMD company • The Cardiology section is often updated and may provide recent data on trials or other news • It is not developed or maintained systematically, and thus lacks comprehensiveness
mRCT • The meta Register of Controlled Trials is a freely searchable website containing data on registered trials • It is provided by the owner of BioMedCentral • It’s a good source on recent or ongoing (thus unpublished) trials • While interesting for the clinical researcher or meta-analyst, it’s scope is limited to RCT
PubMed • PubMed is the web (and free) version of MEDLINE (provided by the US National Library of Medicine) • It contains data on articles printed every day in several thousands medical journals around the world, even if there is some bias toward US and English publications • It is reasonably comprehensive and sophisticated, especially for the expert user • Nonetheless, many papers can still be missed by the MEDLINE indexers, and using PubMed requires some expertise
PubMed: tips and tricks • There are 4 basic ways to search PubMed: • Free text searches • Searches with descriptors(Medical Subject Headings, MeSH) • Clinical queries(specific filters for studies or topics) • Limits(enable the searcher to select several characteristics, such as language, article type, study type, and so forth) • The ideal search combines one or more of such instruments to obtain precise and concise answers to the clinical question
Scholar Google • Scholar Google is provided for free by the Google company • It contains citations and direct links to abstracts or full text articles • In addition, it enables citation analysis, thus forward and backward snowballing • It’s not yet very structered, and highly relevant citations might not be included or missed because buried among thousands of non-relevant ones
The Cochrane Collaboration • The Cochrane Collaboration provides abstracts of systematic reviews for free and full texts and additional services for a fee • It contains the most rigorous systematic reviews available to date on treatment • No comprehensive systematic reviews are yet available for other topics • Many reviews, while highly valid and pertinent, might be outdated because of infrequent updates
UpToDate • UpToDate is provided for a fee by an American company • It provides qualitative reviews of most topics, with the specific features that reviews are updated very frequently • No strict methodology for review production or update is enforced • In addition, it might seem superficial and not detailed enough for experts of a topic
WebMD • WebMD is a comprehensive website for healthcare professional, that can be accessed upon fee subscription • It is relatively comprehensive but unstructured • Resembles (albeit with less cardiology focus) www.medscape.com, www.theheart.org, and www.tctmd.com
Web of Science • Provided for an expensive fee by Thompson-Institute for Scientific Indexing, is the basis for the computation of impact factors and citation indexes • Contains titles and abstracts from several thousands journals • In addition, it enables forward and backward snowballing • However, it lacks the comprehensiveness of EMBASE or PubMed
Take home messages The most important tips to remember when looking for scientific literature are:
Take home messages The most important tips to remember when looking for scientific literature are: 1 – begin with a broad search: it you find too much, you can always refine the search later on
Take home messages The most important tips to remember when looking for scientific literature are: 1 – begin with a broad search: it you find too much, you can always refine the search later on 2 – use as starting points authoritative investigators, seminal papers and/or clear-cut key-words