Presentation on theme: "EBP Step 2: Rapid Access to the best evidence Dr Sue Wells Effective Practice, Informatics & Quality Improvement Section of Epidemiology and Biostatistics."— Presentation transcript:
EBP Step 2: Rapid Access to the best evidence Dr Sue Wells Effective Practice, Informatics & Quality Improvement Section of Epidemiology and Biostatistics School of Population Health
Using PubMed to find research evidence in quickest possible time-future proof your searching! PubMed 101 Get this lecture ppt from CECIL and on “Normal View” find all the step-by step instructions
Medline n widely available on different platforms eg, OVID or PubMed n produced in USA. (National Library of Medicine) n premier electronic source for biomedical literature n contains mostly US/UK journals n 4000 / 10,000 published worldwide n uery.fcgi?DB=pubmed
Tip Number 1 GOOGLE PUBMED!
PubMed – Free Internet version of Medline
Go straight to the INDEX- MeSH
MeSH 1 n Medline Subject Headings (MeSH terms) are assigned to each article. n Provide consistent way to retrieve articles n MeSH “a controlled vocabulary organised in a tree structure” n index = like chapter headings in a text book –Major Subject Headings (eg Leg) Subject Headings (eg knee) –Subheadings (eg cruciate ligament) n Each new paper is “tagged” by NLM librarians using MeSH terms representing the key things about each study (eg rct ligament surgery)
CLINICAL SCENARIO A 65 yr old woman with stable angina and on HRT for 8 years comes to see you. She has read a magazine article about the possible harms of Hormone Replacement Therapy (HRT) on heart disease. She n Is a non-smoker. n Has a BMI of 25 n Has no menopausal symptoms Should her prescription for HRT be stopped?
Reframe into PECOT question Among postmenopausal women with angina or other coronary heart disease (P), Does hormone replacement therapy (HRT) (E), Compared to no HRT (C), affect the risk of further CHD events (eg MI, bypass surgery) (O) over the next 5 years (T) ?
HRT EXAMPLE Break the question into the following components ParticipantsExposureCompari son OutcomeTime angina or coronary heart disease AND Post- menopausal Hormone replacement therapy OR HRT No HRTCoronary heart disease events 5 years AND
MeSH 2 n Explode retrieves all articles with that MeSH term or a term beneath it on the tree eg explode “leg” retrieves all articles tagged with either leg, hip, thigh, knee, ankle, foot n Restrict (or Focus) restricts search to those articles where the specified MeSH term is the major focus. n Previous indexing -Subject Headings change over time – may need to check “old” headings as well as MeSH term
Introducing PubMed TABS n HISTORY –Gives you a summary of what you have searched, limits or filters used and number of articles retrieved
LIMITS Limits your search eg; to particular study types, population groups studied, or language
Helpful tip- clear limits or every search from now on will have them!
“Clinical Queries” searches for you by applying a filter for specific study types
Highlight the search terms, copy (Ctrl-C) and paste (Ctrl-V) into Clinical Queries dialogue box
SENSITIVITY Sensitivity is calculated by Results of a sensitive search RCT’s required (blue) Results of a specific search number studies found total number of relevant studies
What if the question is not about an intervention?
Scenario n You are a 2 nd year house surgeon at Whangarei-its night time. n 16yr old brought in by Mum with signs & symptoms of acute appendicitis n Ring surgeon on call, up to theatre and remove a normal appendix n Find patient has PID – gonorrhea n Disappointed in your mistake you wonder if a CT scan would be have been useful as a diagnostic test. You decide to search PubMed.
Reframe into PECOT question Among adolescents and adults who are admitted acutely with signs and symptoms suggestive of appendicitis (P), Will a computerised tomography scan help to differentiate (O) between those who have acute appendicitis (E), Compared to those with other diagnoses (C), At the time of admission (T) ?
Appendicitis Example Break the question into the following components ParticipantsExposureComparisonOutcomeTime Adolescents and adults Acute Appendicitis Not acute appendicitis CT ScanOne point in time AND
GO TO MeSH
Still too many to scroll through? – what could I do now??
OK- what if you have a really tricky question and it doesn’t map to a MeSH term ????
n Should interventional radiologists or general surgeons be using antibiotic or antiseptic-impregnated central venous lines to prevent line- associated sepsis?
Reframe into PECOT question For patients requiring a CVP line (P), Does an antibiotic or antiseptic-impregnated central venous line (E), compared to a non-drug impregnated one (C), prevent line-associated sepsis (O) over the time of use (T) ?
CVP line example Break the question into the following components ParticipantsExposureComparisonOutcomeTime Any hospitalised patient antibiotic or antiseptic- impregnated central venous line “Plain” CVP line Infectio n Sepsis death Over time of use AND
MeSH- type in CVP line
Scroll down to “Display”
Click on Click on drop- down menu
MeSH terms “tagged” to this publication Catheterization, Central Venous
What about the other options? n Send to search box with OR n Send to Search box with NOT
Boolean AND AND Children aged 2-15 Asthma
Boolean OR Asthma Bronchitis Green area = Asthma or Bronchitis
Boolean NOT Asthma not drugs Drug therapy Yellow circle = Asthma White Circle = Drug therapy
PubMed Single Citation Matcher Quick way to find a single paper A consultant mentions in passing a randomised trial published in the Lancet in 2001 looking at prevention of deep vein thrombosis on long flights. You want to find a copy of the paper.
Use Single Citation Matcher tool-put in journal name, year and title words
Organisation of Evidence Adapted from Haynes RB (2001). Evidence-Based Mental Health 4: Evidence-based guidelines eg NZGG
Megasearch engines eg TRIP, SumSearch (just google!) n one stop shops for Evidence based information n multi-database search n includes –Evidence-based synopses (eg EBM journals), –global guidelines, –E-textbooks, medical images, –Patient Information Leaflets, –Systematic reviews, Health Technology assessments, – Core general medical journals, specialist journals ·etc n very dependent on spelling, very dependent on appropriate terms n Use MeSH terms!!!! without [MeSH]