Skip to main content

Evidence Hierarchy: Resource of the week #45

What is it?
The Evidence Hierarchy is a pyramid that aims to represent the relative quality of evidence, the hierarchy, that can be determined from various study types. It is suggested that not all evidence is the same, with different study types being subject to strengths, weaknesses, flaws and biases.
The study types listed at the top of the pyramid are considered to provide better quality evidence than those at the bottom.

There are a variety of different definitions of what is included in the pyramid and there is even some contention as to how useful it is.


Key Features
One of the key things to remember is that the pyramid is only giving you a representation of the quality of the study design, not whether the article you are looking at is “good” or “poor”. You will still need to critically appraise the research paper – for example you may be looking at a randomised controlled trial, but if it has not been carried out well, the article may not be helpful for you.

eTutorial
You can try our etutorial Evidence Hierarchy to learn more about the evidence hierarchy. We also include the description of some common study types.

More help?
You find more about the evidence hierarchy and evidence-based medicine in our book collection

Comments

Popular posts from this blog

Login to Library Search – step-by-step instructions for NHS staff

  Library Search is a discovery tool, allowing you to find items within the library collections. You can search Library Search without logging in to view books and ebooks available in our collections. By logging in to your library account on Library Search you can access a range of additional functionality, such as: Viewing details of your library account Submitting a request to hold a book for you Adding items to your e-bookshelf Saving searches Note that for NHS users logging in to Library Search does not give you access to full-text items. As an NHS member of staff you access online resources using your NHS OpenAthens username. Anatomy of a Library Card First let’s take a quick look at the most important components of your library card. Your library card and library card number give you access to print resources as well as library services. They confirm that you are a member of the library. Your name : this will be printed on your card, so you’ll know it’s yours!...

How to find a Keele eJournal on Library Search?

Library Search includes an A-Z list of the ejournal collection available at Keele University. Note that NHS-subscribed ejournals are not available via the Library Search interface. There are a number of different ways to look for Keele ejournals on Library Search. This blog post will just give you one simple route. 1. Start at the Library Search home page. Click the more option on the top menu bar – this is represented by the 3 dots The top menu bar includes the more option represented by 3 dots 2. Select the Keele eJournals A-Z option. A range of extra options are presented - choose Keele eJournals A-Z 3. Keele eJournals A-Z search interface. You are then presented with the Keele eJournals A-Z search interface, You can either browse through the titles available alphabetically or enter your journal title into the search box and click search. Screen-shot of the Journal search interface, including an alphabetic list In this example I have en...

Ebsco database training in October 2026

 Ebsco are delivering a range of training opportunities this month as below. Please book for these online courses using the links below: Advanced Searching for CINAHL in EBSCOhost This 60-minute session will introduce advanced search concepts for searching in CINAHL on the EBSCOhost interface. In this session we will look at navigating the interface, the use of CINAHL (Subject) Headings, the application of filters, reviewing available options to save, share, download and export search results, as well as saving, editing and downloading searches and creating and managing alerts. • Wednesday, 14th October @ 2.00pm • Thursday, 29th October @ 10.00am   Exploring the NHS Knowledge & Library Hub – Updated This 60-minute webinar provides a comprehensive introduction to the Hub (EBSCO Discovery Service), featuring recent enhancements to the interface. • Tuesday, 27th October @ 2.30pm   Supporting Systematic Reviews Part 1 – Searching The first of two parts, ...