Where can I find the results of a clinical trial?
Use the trial number to find the right record: where to look for results, how plain-language summaries help and what to ask when information is missing.
Your last trial visit is over. Blood samples have been taken, questionnaires completed, and perhaps you have organised months of journeys to the clinic. Now you want to know what came of taking part. But your searches mostly find descriptions of the study, with few answers.
Finding the results starts with identifying the right trial and distinguishing its timeline from your own participation.
Your last visit is not necessarily the end of the trial
People often join a trial at different times. When your treatment finishes, others may still be receiving treatment or attending follow-up visits. The collected data also need to be checked and analysed.
“No longer recruiting” therefore does not mean that results are available. It initially tells you about enrolment. At your final appointment, explicitly ask when an analysis is expected and how you can find out about it. Note a contact address you can use after visits have ended.
The trial number is more reliable than the medicine's name
One medicine may be investigated in several trials: for different conditions, in different combinations or after different previous treatments. A news item about that medicine might not concern your trial.
The trial number in your documents helps narrow the search. For EU medicine trials, use the public CTIS search. For older trials, the EU Clinical Trials Register may help. An identifier beginning with “NCT” belongs to ClinicalTrials.gov.
Also compare the condition and the treatments being studied. Save the matching record. You can return to it later instead of starting again among similarly named trials.
A description is not yet a result
A description sets out what researchers intend to find out. A results report presents what they actually observed. Check whether the text explains a planned investigation or contains data that have already been analysed.
The “Trial results” section in CTIS may contain a “Layperson summary”: a results summary written in plain language. This is a useful starting point when scientific tables and abbreviations make a report difficult to approach.
First, identify the question being answered. Was it about fewer symptoms, a tumour's response or how long an effect lasted? These findings are not interchangeable. Then look at the treatment used for comparison and the unwanted effects that occurred.
If your search remains unresolved
An empty results section cannot tell you whether analysis is ongoing or publication is still pending. Send the trial number to the site and ask about progress and a plain-language summary.
When you find something, take the text to your next consultation. Mark the statement that concerns you. “I read online that the trial was successful” can then become a specific question: “What does this finding mean for people in my situation?”
This information is not a substitute for a conversation with your doctor.