PIF TICK guide

What is clinical evidence?

Health information about treatments should be based on clinical evidence. Clinical evidence comes from clinical research. Research should be checked by other experts before it is published. This is called peer-review.

Why does it matter?


If the health information you are reading, watching or listening to is evidence-based it can help you decide whether to trust and use that information.

How can I tell which clinical evidence is best?


There are many types of clinical evidence and research. The pyramid of evidence below ranks evidence from high to low. It was developed by doctors to help them rate the quality of evidence. As a general rule, the more people included in the research, the more reliable the findings.

How can I be sure about the evidence?


Sometimes it is difficult to be certain about clinical evidence. Health information should tell you if the evidence is uncertain or if different medical experts have different opinions. 

Why would lower quality evidence be used?


Guidelines and reviews do not exist for all topics. In this case, other research from the pyramid will be used as the best evidence available. We’ve explained some of the terms in the pyramid.

What does research tell me?


Everyone is different. Research is based on human clinical trials or data from NHS records but can only tell you the most likely outcome. It can never guarantee what will actually happen to you.

What about ‘real world’ patient data?


In the digital age it is easier to see what happens once treatments are used in the general population. Real world data is important because some groups of people are under-represented in clinical trials.

Can I share my data?


You can help build evidence on your condition or treatment by giving consent for your treatment data to be shared for research. You can check how your data will be used and how your identity will be protected. 

Pyramid of evidence

Pyramid of evidence with descriptions of each level

Pyramid adapted from The Evidence Based Medicine Pyramid https://s4be.cochrane.org/blog/2013/02/14/the-ebm-pyramid


Download the PDF guide

What is clinical evidence?


Publish date: June 2021
Review date: June 2023

Image of the PIF guide 'What is clinical evidence?'

See more