Participate in studies: tips

Research in medicine relies on volunteer participants. Before you make yourself available as a test subject, however, you should consider a few things, for example the effort and possible risks

According to the Federal Office for Drugs and Medical Devices, around 1,000 clinical studies are approved in Germany every year, for which several thousand participants are sought

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Klaus H. is familiar with matters of the heart. The 75-year-old Berliner has lived with atrial fibrillation for many years. A cardiac arrhythmia that affects almost 1.8 million people in Germany. You therefore also have a higher risk of stroke. About every third stroke in the elderly can be traced back to it.

Many people don't even notice when their heart trips. "It happened to me so often that I noticed shortly beforehand that it was going to start again," says Klaus. Because he not only suffers from cardiac arrhythmias, but also has diabetes and kidney problems, he is what medical professionals call a high-risk patient. Therefore, he is now taking part in a clinical study that is looking for precisely such patients as participants.

Study design: comparison of two treatment methods

It is called Closure AF, and almost 60 specialized heart centers in Germany are involved. Doctors want to use the examination to find out: What is the best therapy for people with atrial fibrillation who, in addition to a high risk of stroke, also have other risks? "This question has not yet been investigated in a large study," says Dr. Carsten Skurk, Deputy Director of the Medical Clinic for Cardiology at Charité Berlin.

The study aims to compare two therapy options in high-risk patients like Klaus H. On the one hand, an intervention that can reduce the risk of stroke. This closes a certain part of the left atrium in the heart: the so-called atrial ear, where the blood clots usually form. "The other half of the patients are currently receiving the best possible drug treatment," says Skurk. So well-tolerated drugs that inhibit blood clotting - and thus prevent a stroke.

Procedure or pills?

So-called controlled clinical studies compare different treatments. In this way it can be assessed which therapy is more effective.

No clinical studies without test subjects

Regardless of whether it is a question of scientifically investigating new treatments or comparing therapies with one another, there would be no clinical studies without volunteers. "And without good studies, there would be no scientifically proven findings in medicine," says health scientist Professor Ingrid Mühlhauser, who is involved in the German Network of Evidence-Based Medicine for patient information and participation.

Clinical studies in Germany have to meet strict legal requirements in order to limit possible risks for the participants. The Federal Institute for Drugs and Medical Devices (BfArM) or the Paul Ehrlich Institute (PEI), for example, must give their approval in advance. There, the so-called study protocols are checked, in which scientists present important information about their research project - for example, which studies have already been carried out on the topic and why a further investigation is nevertheless necessary.

Scientists also have to submit their protocols to an ethics committee, which uses ethical, medical and legal criteria to weigh the benefits and risks for the participants. These controls are usually effective: Serious clinical trial incidents are extremely rare in Europe.

Inform about possible risks before participating

Nevertheless, one should consider what one expects from participating in the study. For some, what counts may be the thought that by doing this they want to support clinical research. But sometimes your own medical history is also decisive.

"If a patient is directly affected by an illness, then that can be a good reason for participating," reports Ingrid Mühlhauser. This does not only apply to clinical studies on cancer, in which patients sometimes hope that their participation will give them early access to new treatment methods.

Study participation: this is how it works

© W & B / Michelle Günther


© W & B / Michelle Günther

1. Recruitment

Doctors provide direct information on studies. Study registers, for example, help online

© W & B / Michelle Günther

2. Education

A doctor must first inform about the risks and the test person must sign a declaration of consent

© W & B / Michelle Günther

3. Classification

For many studies, the subjects are randomly assigned to the groups

© W & B / Michelle Günther

4. Participation

Depending on the allocation, you get a drug or a placebo content: linkbyid

© W & B / Michelle Günther

5. Control

Patients are regularly examined or questioned in study centers, for example

© W & B / Michelle Günther

6. Result

At the end of the study, the results should be published


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Doctors have to point out in the educational discussion that as a test subject you are not necessarily in the group that receives such a new drug. Only when the participant has been informed about the benefits and risks of the examination and has signed a declaration of consent can it start.

Who finances the studies

However, some people may want to know beforehand who is funding the study. In fact, most of the clinical studies in Germany are carried out by pharmaceutical companies. According to the German Study Register, a total of 256 Phase III studies were completed in 2017 that had a so-called commercial sponsor.

Non-commercial sponsors, on the other hand, were only found in 33 comparable studies. These are financed, for example, by the Federal Ministry of Education and Research, the German Research Association, foundations, hospitals and research centers.

New active ingredients

Before new drugs can be tested on people, they are examined in the laboratory. This is followed by Phase I, Phase II and Phase III studies for which participants are being sought. A new preparation can only be approved by the German or European drug authorities once a phase III study with many participants has been successful.

It doesn't have to make a difference for the participants, says Mühlhauser. "Clinical studies are subject to strict rules, and industry studies are usually carried out in a highly professional manner." On the other hand, it is more problematic for science.

Because it has been known for a long time that the results are only published if they are positive - and thus enable the approval of a new drug, for example.

Industry not interested in certain investigations

In addition, some issues are completely ignored for the industry. This includes, for example, which established therapies are best for treating uncomplicated diseases. For example, with urinary tract infections: "Often there is an antibiotic, sometimes a pain reliever or a herbal preparation. But what works best, nobody had previously investigated," explains Dr. Guido Schmiemann from the University of Bremen.

The ICUTI study compared the treatment success of ibuprofen with an otherwise often used antibiotic. The result: the women who were given ibuprofen recovered just as quickly. "That showed us that you can do without antibiotics when treating uncomplicated urinary tract infections," says Schmiemann.

Studies on medicinal plants

According to surveys by the "State of the World’s Plants", only around 16 percent of all known medicinal plants have so far been scientifically examined. Large-scale clinical study projects often fail due to funding.

Another study deals with the effects of bearberry leaf extract. "The vast majority of herbal active ingredients have not been investigated in meaningful studies. The pharmaceutical companies are not interested in changing this because it is not worth the effort for them," says Schmiemann. The funding therefore did not come from industry, but from the Federal Ministry of Education and Research.

Financial incentives - a sensitive issue

Such studies can hardly attract participants with financial incentives. Expense reimbursements are not the rule anyway, but they can play a role in phase 1 studies - when drugs are tested on humans for the first time. Above all, people with low incomes make themselves available for this. This is a sensitive topic for researchers, because there is a risk that such test subjects will take part in several examinations in a row, even though this is forbidden.

Health scientist Mühlhauser sees other advantages for patients. "The medical care of participants in clinical studies is usually very good, and they are looked after by particularly committed doctors and study nurses." Incidentally, the fact that the test subjects will receive preferential medical treatment is not an empty promise - it is also a study result.

What participants should be aware of

Ask questions! Before you agree to participate in a clinical study, you should clarify the following points: What should the study show? What is known about the active ingredient in question or the procedure? What do you have to consider while participating? How much time do you have to plan for preliminary and follow-up examinations?

Weigh it up! Participation in a study can have advantages, such as close medical care, new therapies or indirectly helping other people.

The disadvantages: The appointments can take up a lot of time. Perhaps the treatment being tested is of no greater benefit. And although the risks are usually small, side effects can occur.

Your contribution is important. With their participation, test persons make a contribution to research. They can also ask for something for this. The German Medical Association recommends that patients ensure that the study is entered in a public central study register ( or, in the case of international studies, at You should also have written confirmation that the results will actually be published.

Participation is voluntary. Are you no longer sure about some points? You can revoke your consent to participation at any time after the start of the study without giving reasons.