Finding Relevant Evidence
The narration between entries paraphrases; it never reads an entry aloud before the entry plays. Every entry in this lecture plays exactly as it does on its own page — same file, same speed, nothing laid over it.
What you can do after this
- Say what makes a search systematic rather than looking something up
- Name the preappraised forms and say why the most useful of them is the scarcest
- Tell a systematic review from a narrative review
- Name the main databases and say what each one covers
- Say why a general search engine is not a source of evidence
What it covers
36 entries in 6 topics. Each number links to that entry on its own.
-
1. What searching is
-
2. The lower levels, and what they are for
-
3. Preappraised evidence
-
4. Journals and textbooks
-
5. The databases
-
6. Constraints, and the step people skip
Check yourself
What makes a search systematic?
A method you could write down and someone else could repeat, run across more than one source. Databases index different journals and search differently, so a single database returns a partial answer every time.
Why is the most useful form of evidence also the scarcest?
Because the ordering follows effort. The more appraisal and synthesis someone has already done for you, the more expensive that work was, and so the rarer it is. For most clinical questions no systematic review exists at all.
How do you tell a systematic review from a narrative review?
By its method, not its author. A systematic review states eligibility criteria in advance and follows a reproducible process. A narrative review is an expert writing about a literature, and being written by an eminent person does not make it systematic.
Why is a general search engine not a source of evidence?
It has no defined coverage, so you cannot say what it failed to find; no index, so you cannot search by subject heading; and no way to reproduce the search, which is the requirement that makes a search systematic in the first place.
What is the highest-value step in this unit?
Asking a healthcare librarian, who searches for a living. It is also the step most reliably skipped, which is why the course states it as its own entry rather than as an aside.
Lecture transcript
The narration as recorded, in order. Where an entry plays, the transcript links to it rather than reprinting it — the entry plays from its own file, unaltered, and says the same thing on its own page.
This is step two, and it takes the question you built in unit 2 as its input. If that question is vague, nothing in this lecture rescues it. Two ideas run through the whole of it. The first is that you are assembling a body of evidence rather than finding a paper — the correction this course makes more often than any other. The second is that no single database holds the answer, because they index different journals and search differently. This is Part A, which is about where evidence lives: the forms it takes, and the sources that hold them. Part B is how to get it out. By the end of this half you can say what makes a search systematic; name the preappraised forms and say why the most useful is the scarcest; tell a systematic review from a narrative one; name the main databases and their coverage; and say why a general search engine is not a source of evidence.
Six videos setting up the step. The one to hold is the body of evidence — the correction this course makes more often than any other.
Step two, following on from the question.
EBP 0301 Searching Is Step Two
Searching is step two, and it takes the question built in unit 2 as its input.
What the word systematic is doing.
EBP 0302 A Systematic Search
A search by a method you could write down and someone else could repeat. That is what separates it from looking things up.
Searching as a named competency.
EBP 0303 Searching Is a Competency
Searching is one of the EBP competencies, which means it is a skill to be developed and assessed rather than assumed.
Why one database is never enough.
EBP 0304 More Than One Source
Databases index different journals and search differently. One database returns a partial answer every time.
The phrase this course repeats most.
EBP 0305 The Body of Evidence
What you are assembling is a body of evidence, not a paper. This is the correction the course makes more often than any other.
What gets considered.
EBP 0306 All Evidence Is Considered
All evidence is considered, then weighed. Excluding a design before you have looked is a decision made without information.
Three videos on designs that cannot establish cause, and what they can legitimately do instead.
What the lowest levels are good for.
EBP 0307 What a Case Study Can Do
A case study can describe, alert and generate hypotheses. It cannot establish that something works.
And the caution that goes with it.
EBP 0308 Caution on High-Bias Designs
High-bias designs are read for what they offer and their limits are stated rather than quietly discounted.
Both kinds appear in a search.
EBP 0309 Internal and External Evidence
A search covers external evidence, and your own internal evidence sits alongside it in the decision.
Ten videos on evidence someone has already done the work on. Watch the ordering point at the end of the topic — the list is by availability, not by strength, and reading it as a hierarchy is a mistake.
Evidence someone has already appraised.
EBP 0310 Preappraised Literature
Literature that has already been appraised and synthesised by someone else, which saves the step you are about to learn.
What forms it comes in.
EBP 0311 The Forms of Preappraised Evidence
Systematic reviews, critically appraised topics, evidence summaries and guidelines. Different amounts of work already done.
What it buys you.
EBP 0312 What Preappraisal Saves
It saves the search and the appraisal, both. What it does not save is the judgement about whether it applies to your patient.
The form at the top.
EBP 0313 Systematic Reviews as the Heart of EBP
The systematic review is described as the heart of evidence-based practice, because it answers a question against the whole body rather than one study.
And the caveat immediately after.
EBP 0314 There Is Often No Review
For most clinical questions no systematic review exists. The strongest form is also the scarcest.
A distinction that matters at appraisal.
EBP 0315 Systematic Review Is Not Narrative Review
A systematic review has prespecified criteria and a reproducible method. A narrative review is an expert writing about a literature.
A shorter form.
EBP 0316 Critically Appraised Topics
A critically appraised topic answers one focused question in a short summary. Less exhaustive than a review, and much faster.
Evidence bundled for use.
EBP 0317 Consolidated Evidence
Evidence consolidated into a usable form, sitting between raw studies and a guideline.
How these forms are ordered here.
EBP 0318 Ranked by Availability, Not by Strength
These forms are listed by how available they are, which is not the same as how strong they are. Do not read the list as a hierarchy.
Why the good stuff is rare.
EBP 0319 Why the Most Useful Is the Scarcest
The more work someone has already done for you, the rarer it is, because that work is expensive. The ordering follows effort.
Four videos on where primary research appears and the caution that goes with it.
Resources built for the bedside.
EBP 0320 Point-of-Care Resources
Resources designed to answer a question in the time you have during a shift.
Where primary studies live.
EBP 0321 Journals Are the Entry Point
Journals are where primary research appears first, and where a search ends up when nothing preappraised exists.
The caution about journals.
EBP 0322 Not Every Journal Article Is Evidence
A journal carries editorials, commentary and opinion alongside research. Being in a journal is not the same as being evidence.
Where textbooks fit.
EBP 0323 Textbooks Answer Background Questions
Textbooks answer background questions well and foreground questions badly, because they are out of date the moment they print.
Nine videos naming the instruments. The last three are the ones that change behaviour: cost, coverage, and the difference between a database and a search engine.
The main instrument.
EBP 0324 Bibliographic Databases
A bibliographic database indexes records — citations and abstracts — rather than holding the papers themselves.
The other kind.
EBP 0325 Full-Text Databases
A full-text database holds the articles. What you can reach depends on what your institution pays for.
The first named database.
EBP 0326 CINAHL
The nursing and allied health index, and the first place a nursing question usually goes.
The second.
EBP 0327 MEDLINE
The biomedical literature index, produced by the National Library of Medicine.
How most people reach MEDLINE.
EBP 0328 PubMed
A free interface to MEDLINE and more. Free to search, which is not the same as free to read.
The database to check first.
EBP 0329 The Cochrane Database of Systematic Reviews
The database of systematic reviews. Worth checking first, because a review there answers the question outright.
Two further databases.
EBP 0330 Embase and PsycINFO
Embase for the European and pharmacological literature, PsycINFO for behavioural and mental health.
Where to find guidelines.
EBP 0331 Guideline Sources
Guidelines are held in their own repositories rather than in the bibliographic databases. Unit 8 appraises them.
The literature outside the journals.
EBP 0332 Grey Literature
Reports, theses and conference material that never entered a journal. Harder to find and sometimes the only thing there is.
Four videos to close. Cost is a real constraint on practice rather than a footnote, and the last video is the highest-value step in the unit.
A constraint stated plainly.
EBP 0333 Cost Shapes What You Can Search
What you can search depends on what someone pays for. This is a real constraint on practice, not a footnote.
Knowing what you are searching.
EBP 0334 A Licensed Database Tells You What It Holds
A database states what it indexes. Knowing its coverage tells you what your search could not possibly have found.
The line this unit draws hardest.
EBP 0335 A Search Engine Is Not a Source of Evidence
A general search engine is not a source of evidence. It has no defined coverage, no index and no way to reproduce a search.
The step most often skipped.
EBP 0336 Ask a Healthcare Librarian
A healthcare librarian searches for a living. This is the highest-value step in the unit and the one people skip most reliably.
That is where evidence lives. Against the outcomes. A search is systematic when it follows a method you could write down and someone else could repeat, across more than one source. That is what separates it from looking something up. The preappraised forms run from systematic reviews through critically appraised topics to guidelines, and they are listed by availability rather than by strength. The more work someone has already done for you, the rarer it is, because that work is expensive. A systematic review has prespecified criteria and a reproducible method. A narrative review is an expert writing about a literature. The difference is method, not authorship. You can name the databases: CINAHL for nursing and allied health, MEDLINE through PubMed for the biomedical literature, Cochrane for systematic reviews, Embase and PsycINFO for different coverage again. And a general search engine is not a source of evidence, because it has no defined coverage, no index, and no way to reproduce what it did. Part B takes the question into these sources and builds the search itself.
This is free, and stays free. If it helped, here is what keeps it running.