Evaluating potential treatments for COVID-19 in older people

Lady fitting elderly lady with face mask


PRINCIPLE is a nationally prioritised research study to find treatments for COVID-19 for people in the community who are at higher risk of complications.

Coronavirus disease 2019 (COVID-19) can be more severe in older people, and people with underlying health conditions.  At the moment, there are no specific treatments for use in the community that we know of, that definitely work against COVID-19.  By taking part in this study, you will be contributing towards the understanding of how we can treat COVID-19 and how the symptoms progress. 

The study is being offered across the country. You can read more on the study website

PRINCIPLE is being delivered by the University of Oxford and is funded by UK Research and Innovation and the Department for Health and Social Care through the National Institute for Health Research.

Who can take part?

The study is for people with ongoing COVID-19 symptoms. People who feel they are already well on the way to recovery should not take part. 

To take part you need to be:

Aged over 65, or aged 18 to 64 with at least one of the following conditions:

  • weakened immune system due to a serious illness or medication (e.g. chemotherapy)​,
  • heart disease or high blood pressure​,
  • asthma or lung disease​,
  • known diabetes,
  • liver disease,
  • stroke or neurological problem​.
  • a BMI of 35 or above.


Experiencing the following symptoms of COVID-19 for fewer than 15 days:

  • A continuous cough - this means coughing a lot for more than an hour, or 3 or more coughing episodes in 24 hours (if you usually have a cough, it may be worse than usual)​,
  • a high temperature - this means you feel hot to touch on your chest or back (you do not need to take your temperature)​,
  • a loss of, or change in, normal sense of taste or smell


Have had a positive test result for COVID-19 within the past 14 days and are unwell

More information about how to join the trial

Participation is entirely voluntary. It is up to you to decide whether to take part in the trial or not.  The decision to not take part will not affect the standard of care you receive from the NHS in any way, now or in the future.

How to join

Screening questionnaires

There are several steps to joining the PRINCIPLE Trial. The first is answering a few screening questions to assess your eligibility. There are different questionnaires depending on where you live in the UK:

England, Wales or Northern Ireland


Care home resident

If you are selected, you will need to answer some questions online or on the telephone (0800 138 0880) to check you are suitable, and provide consent (giving your permission to take part). You can also nominate a ‘study partner’ (family, friend, carer) to help you with taking part in the study.

The study team are also recruiting through GP surgeries.  Your GP, or a study nurse or doctor, will check your medical notes to make sure it is safe for you to be in the study.

Read about what the trial involves 

Further information

Participation Information Sheets provide full details about the research study and are written in a non-technical way.  The information sheets have also been translated into multiple languages.