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Screening, explained
What happens between a match and a place in a study, and why hearing no is common.

A match from Origin means a study’s published requirements line up with what you told us. Screening is where the research team checks the rest.
Why screening exists
Every study is designed to answer one question in one group of people. Its protocol lists who can take part and who cannot, called inclusion and exclusion criteria. Some protect your safety, such as leaving out people who take a medicine that could interact with the one being tested. Others keep the results clear, by making sure everyone in the study shares the condition being studied.
How it usually goes
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A first phone call
A coordinator from the study asks a handful of questions to see whether the basics line up. You can ask your own questions too, and nothing is agreed on the call.
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Consent before anything else
At the site, the team walks you through the consent form. No tests happen until you have read it, asked what you want to ask and signed.
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The screening checks
The team then checks your health against the study’s full requirements. This may mean blood tests, a physical exam, a scan or a look at your medical history.
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A yes or a no
Some answers arrive the same day; lab results can take a week or two. Either way, the team tells you and explains what happens next.
Hearing no is common
Many people who start screening do not go on to join that study. A blood result slightly outside a range, a medicine you take, or a detail of your history can rule you out of one study and still leave you a good fit for another. A no at screening says nothing about your worth as a volunteer.
If you are turned down, ask whether the team can tell you why. It may help with the next study, and some sites keep a list of volunteers for future research if you agree.
Is there a cost?
Screening tests that the study requires are normally paid for by the study, not by you or your insurance. Ask the coordinator to confirm this before the visit, along with whether travel or parking is covered.
More guides
- Placebo and blindingWhy some people receive a dummy treatment, and why nobody may know who did.
- Talking to your doctorHow to bring a study up with your own doctor, and what to ask them.
- Your data in a studyWhat a study records about you, who sees it, and what happens to it later.
- When a study endsYour last visit, your results, your treatment and what comes next.
Ready to hear about studies?
Join once with your ZIP code and a research area. It is free, and you can stop whenever you like.