Step Two Finding the best evidence 1. Walk through one 2. Do own searches
Mar 31, 2015
EBM and Systematic Review
EBM (quick & dirty) Steps
Answerable Question Search Appraise
Apply
Time: 90 seconds < 20 articles This patient survives!
Systematic Review Steps
Answerable Question Search ++++ Appraise x 2 Synthesize Apply
Time: 6 months < 2,000 articles This patient is dead
Find a systematic review!!
Start up Start Explorer and enter
www.pubmed.gov Put on CAPS lock
So that AND and OR are in CAPITALS Start 2nd Explorer window, enter
www.tripdatabase.com
Using the question to guide searching
Scenario - You are interested in checking the hearing of elderly patients, and have heard that the ‘whispered voice test’ is good.
Question Population Indicator (intervention, test, etc) Comparator Outcome
Using the question to guide searching
Scenario - You are interested in checking the hearing of elderly patients, and have heard that the ‘whispered voice test’ is good.
Question Population – in elderly patients does Indicator – a ‘poor’ whispered voice test Comparator – a ‘normal’ whispered voice test Outcome – predict abnormal audiogram
1. Underline the key terms2. Number the order of importance from 1-43. Think of alternate spellings, synonyms, &
truncations
Using the question to guide searching
Scenario - You are interested in checking the hearing of elderly patients, and have heard that the ‘whispered voice test’ is good.
Question Population – in elderly patients does Indicator – a ‘poor’ whispered voice test Comparator – a ‘normal’ whispered voice test Outcome – predict poor hearing (audiogram)
1. Underline the (root of the) key terms2. Number the order of importance from 1-43. Think of alternate spellings, synonyms, &
truncations
1
2
3
Stepwise searching Search with #1 PICO item
Whisper* Then go to “Clinical Queries”: diagnosis
Whisper* (again) Add #2 PICO item
whisper AND (hear* OR audiogram)
Combining terms with Boolean operators – AND
chitosanweight
weight AND chitosan - has both terms
IN CAPITALS
Your tasks Search for the best single article
(systematic review or trial) for Your question from notes Your own question(s)
When you are finished Print just the abstract for each Write your search strategy on the
page
Boo-le-ans* AND = both terms OR = either term NOT = not this term (ADJacent, NEAR, … = AND +
close)
* George Boole (a man) is claimed to have invented “logic”
Where to the brackets go? If you want
cheese AND fruit
Which do you ask for? cheese AND (apple OR pear OR melon) (cheese AND apple) OR pear OR melon
What does PubMed do with if AND and OR? Cheese AND apple OR pear (Look at DETAILS tab)
General structure of search
(Population OR synonym 1 OR …) AND (Intervention OR synonym 1 OR …) AND (Comparator OR synonym 1 OR …) AND (Outcome OR synonym 1 OR …) AND
FILTER (for best study type)
Other tips: Search on Title only
Eg [ti](Others are [au] - author; [so], [yr], …)
‘Related Articles’ button(PubMed)
previously identified study (PubMed)Look for the MeSH termsMeSH browser
Before you finish!
Print single most relevant abstract for each question – for both ‘set’ questions and your own questions
More Tips on Effective Searching
Decide the TYPE of question (Rx, Dx, Px, …)
Chose the right database for the type of question, e.g., Intervention: Cochrane Library, PubMed, … Diagnostic: Common Diagnostic Strategies (in
BE), or PubMed: Clinical Queries Prognosis, Etiology: PubMed: Clinical Queries
Hearing problems in childhood Scenario - An immunisation and screening
booklet asks parents whether they think their child has any problems with hearing. While on a committee reviewing these questions, you wonder about the usefulness of this.
Question Population Indicator (intervention, test, etc) Comparator Outcome
Question Type - Rx, Dx, Px, … Database
Hearing problems in childhood Scenario - An immunisation and screening booklet
asks parents whether they think their child has any problems with hearing. While on a committee reviewing these questions, you wonder about the usefulness of this.
Question Population – In well children Indicator - does parental report of concern Comparator - nil Outcome – predict true hearing problems?
Question Type - Rx, Dx, Px, … - Diagnostic Accuracy Database – PubMed: Clinical Queries - diagnosis
Using the question to guide searching Question
Population – (child OR children) AND Indicator – (parent OR parental) AND Comparator - nil Outcome – (hearing)
Question Type Dx – Diagnostic Accuracy
Database – PubMed: Clinical Queries
Using truncation to save on ORs – the * Question
Population – (child*) AND Indicator – (parent*) AND Comparator - nil Outcome – (hearing) AND
Question Type Dx – Diagnostic Accuracy
Database – PubMed: Clinical Queries