PIF TICK guide

What is evidence? Why is it important?


Trusted health information should be based on evidence. This means the health information is fact-checked as much as possible.

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.

What types are there?


This table shows the types of evidence used for common topics in health information.

TypeHealth information it is used for
Clinical researchInformation on benefits and risks of treatment
NHS service informationHow the NHS should plan your care
Patients, carers, service users, surveys and interviewsWhat it’s actually like to live with a condition
Topic expertsWellbeing and practical information on diet and exercise, for example
Clinical textbooks, patient groups and NHS patient dataBackground on causes of an illness, how many people get it, people most likely to get it and how they respond to treatment

How do I know if something is evidence based?


Trusted information will usually list the evidence used to create it. You will see this listed as ‘references’ or ‘sources’. If references are not listed you can ask the producer for them.

How can I be sure?


Sometimes it is hard to be certain. There may not be very much evidence or it might conflict. Health information should tell you if evidence is uncertain.

How do I know it is up to date?


Trusted information will show the date it was created and the date it is due to be reviewed.

How can I tell the quality of clinical research?


As a general rule, the more people included in a research study the more reliable the findings. Research should be checked by other experts before it is published. This is peer-review. You can find out more about the types of clinical research here.


Download the PDF guide

What is evidence? Why is it important?


Publish date: June 2021
Review date: June 2023

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