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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
Pub. Med 101 Using Pub. Med to find research evidence in quickest possible time-future proof your searching! Get this lecture ppt from CECIL and on “Normal View” find all the step-by step instructions
Medline n n n widely available on different platforms eg, OVID or Pub. Med produced in USA. (National Library of Medicine) premier electronic source for biomedical literature contains mostly US/UK journals 4000 / 10, 000 published worldwide http: //www. ncbi. nlm. nih. gov/entrez/q uery. fcgi? DB=pubmed
Tip Number 1 GOOGLE PUBMED!
Pub. Med – Free Internet version of Medline
Go straight to the INDEX- Me. SH
Me. SH 1 n n Medline Subject Headings (Me. SH terms) are assigned to each article. Provide consistent way to retrieve articles Me. SH “a controlled vocabulary organised in a tree structure” 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 Me. SH 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 Participants Exposure Compari Outcome son angina or Hormone No HRT Coronary replacement heart coronary disease heart disease therapy events AND OR Post. HRT menopausal AND AND Time 5 years
Me. SH 2 Explode retrieves all articles with that Me. SH 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 Me. SH term is the major focus. n Previous indexing -Subject Headings change over time – may need to check “old” headings as well as Me. SH term n
Introducing Pub. Med 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 number studies found total number of relevant studies RCT’s required (blue) Results of a specific search Results of a sensitive search
What if the question is not about an intervention?
Scenario n n n You are a 2 nd year house surgeon at Whangarei-its night time. 16 yr old brought in by Mum with signs & symptoms of acute appendicitis Ring surgeon on call, up to theatre and remove a normal appendix Find patient has PID – gonorrhea Disappointed in your mistake you wonder if a CT scan would be have been useful as a diagnostic test. You decide to search Pub. Med.
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 Participants Exposure Comparison Outcome Time Adolescents Acute Not acute CT Scan and adults Appendicitis appendicitis AND One point in time
GO TO Me. SH
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 Me. SH 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 Participants Exposure Comparison Outcome Time Any antibiotic or hospitalised antisepticpatient impregnated central venous line “Plain” CVP Infection Over line time of Sepsis use death AND
Me. SH- type in CVP line
Scroll down to “Display”
Click on dropdown menu
Me. SH terms “tagged” to this publication Catheterization, Central Venous
What about the other options? n n Send to search box with OR Send to Search box with NOT
Boolean AND Children aged 2 -15 AND Asthma
Boolean OR Asthma Bronchitis Green area = Asthma or Bronchitis
Boolean NOT Drug therapy Asthma not drugs Yellow circle = Asthma White Circle = Drug therapy
Pub. Med 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
Saving citations / printing off articles PMID: 11377600 OVID platform 11377600. ui
Organisation of Evidence-based guidelines eg NZGG Adapted from Haynes RB (2001). Evidence-Based Mental Health 4: 37 -38.
Megasearch engines eg TRIP, Sum. Search (just google!) n n n one stop shops for Evidence based information multi-database search includes – – – n n 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 very dependent on spelling, very dependent on appropriate terms Use Me. SH terms!!!! without [Me. SH]