Clinical studies: How to distinguish fake news from real facts
Are you dependent on medication or other medical aids and would like to find out about their scientific background? There are many clinical studies on drugs and medical devices - but what is actually special about clinical studies and how can you distinguish between high-quality and poor-quality studies?
What are clinical trials?
A basic distinction is made between interventional and non-interventional studies. Non-interventional studies are observational studies without any intervention on the part of the researchers. As the treating physicians are not given any instructions on how to treat their patients, non-interventional studies always document the routine treatment for a specific clinical picture.
Clinical studies, on the other hand, are interventional studies. They are designed to gather information on the efficacy, tolerability and safety of therapeutic measures, e.g. a new drug. The safety of such studies is guaranteed by various guidelines and laws and they are approved by the ethics committees of the respective research institutions, for example the universities or hospitals involved.
Interventional studies are divided into four phases:
- Phase I trials: small trials in which the new treatment is used for the first time on healthy volunteers to test tolerability and safety
- Phase II trials: the new drug is used for the first time in around 100 to 300 patients to determine the optimum dosage and obtain initial data on efficacy
- Phase III trials: large trials in which patients receiving the new therapy are compared with a control group in order to test efficacy and tolerability
- Phase IV trials: when the drug is already on the market, in order to investigate the new treatment method once again and to better assess side effects
Clinical trials therefore help to improve the care of sick people. However, conducting such studies is very expensive and is often carried out by the manufacturers of the drugs or medical aids.
What types of studies are there?
The type of study depends on the respective research question, i.e. what you want to investigate or prove. The following study types play an important role in testing the efficacy of a new therapy by means of a clinical trial:
- Randomized: Study participants are randomly assigned to groups. This is necessary so that only the effect of the medication can be compared and no other factors influence the result.
- Controlled: One group of participants receives the new drug to be tested (verum) and the other group receives a common drug or the current standard of care.
- Placebo-controlled: One group of participants receives the verum and the other group receives a placebo (a drug that contains no active ingredient). This allows the researchers to attribute any benefit observed in the participant group with the verum to the new drug and not to any other influencing factors.
- Double-blind: neither the doctor nor the patient knows whether the therapy is a placebo/control treatment or the verum.
Randomized controlled trials are suitable for testing the effect of a drug or medical aid. For example, questions such as: "Is the new drug more suitable for treating disease XY than the previous standard therapy?" are addressed.
The randomization of controlled intervention studies ensures that the results are comparable and meaningful, as the participating patients have comparable disease-specific characteristics.
Briefly explained!
Have you ever read that the result of a clinical trial is statistically significant?
In a clinical trial, for example, it is investigated whether the new drug is actually effective as assumed. A statistically significant result then means that the observed effect between the participant groups, in which one group receives the new drug and the other group the placebo or standard therapy, did not occur by chance, but that an effect of the new drug can indeed be assumed. In this case, this allows the conclusion to be drawn that the new drug is generally effective.
5 tips to avoid falling for mistakes
Now you know what clinical trials are and you can find out about the scientific background of drugs and other medical products. However, it can sometimes be difficult to assess the quality of a clinical trial - not least because there are numerous misconceptions and misunderstandings. Here are five important facts about clinical trials to help you better evaluate clinical trials:
- Placebo-controlled studies are not always the best way to prove the efficacy of a new drug or medical device.
Placebo studies are indeed good for investigating the efficacy and safety of an intervention. However, it is often not ethically justifiable to establish a control group that only receives a sham treatment, for example if a proven effective therapy already exists or if the sham treatment would be associated with pain or harm; after all, who would voluntarily undergo a major operation with all its risks just to have a sham medical device inserted as a control group? In addition, good therapies already exist for many diseases, so it often makes more sense to treat the control group according to the previous standard of care, for example to answer the question "Is therapy X better than the previous standard therapy Y?". - Double-blind studies minimise bias in the results due to the expectations of the patient and/or the physician.
However, double-blinding is not always possible, for example because only the verum causes typical side effects or it is a medical device that is visible in imaging procedures such as ultrasound, CT or MRI. In this case, independent investigators who assess the safety, function or benefit of the new drug or medical device impartially on the basis of objective criteria have proven their worth. - Studies with only a few hundred participants can also be meaningful, as the number of cases is not the only important parameter in studies.
The number of study participants has a major influence on whether an actual effect is highly likely to be statistically significant. With a large number of participants, even small differences are statistically significant, whereas with small studies, only large differences are statistically significant. This means that a study with a large number of participants only shows very small, possibly clinically irrelevant differences as significant. Therefore, the pure number of participants does not always say anything about the quality of the study. However, the follow-up time is also an important parameter of a clinical study, which can be used to prove the effectiveness of a therapy over time. Drop-out rates are not generally higher in studies on invasive procedures than in pharmacological studies.
There are many reasons why someone might drop out of a study, such as moving house or changing doctors. A decrease in motivation for long-term follow-up examinations can also be a factor that influences the drop-out rate - many participants are no longer available for follow-up examinations. According to estimates, the drop-out rate in clinical studies on drugs and medical devices is comparably high and is usually between 10 and 30 %. - Investigator Initiated Trials (IIT) are not always better than manufacturer studies - at best they complement and confirm each other.
IIT are studies that are conducted by independent institutions such as universities and are free of commercial interest. They supplement manufacturer studies on new drugs and medical aids, but cannot replace them. Approval studies in particular must be financed and initiated by the manufacturers because the burden of proof for the benefit of a new drug or procedure lies with the manufacturer.
Would you like to take part in a clinical trial?
By participating in a clinical trial, you make an important contribution to research. There are also advantages for you as a trial participant:
- Access to new treatments
- Thorough medical monitoring, examination and intensive care during the trial
However, the new treatment may also be less effective than your previous therapy or not effective at all. Some side effects of the new medication are unpredictable or you may end up in a placebo group. You will also need to attend regular appointments.
Only take part if the study is entered in a study register, you receive written confirmation that the results will be published and a study protocol is kept. The doctors conducting the study must inform you about the benefits and risks of the study and then obtain your written consent. However, you can withdraw from the study at any time without giving reasons.
However, you should first ask your treating physician for advice if you are interested in participating in a study. Your doctor can classify your current therapy and illness in the context of the study and, if necessary, recommend participation.