**3. Clinical trials on minors**

In paediatrics, it is often that methods and therapies are applied based on studies conducted on adults. But the results in children are not always the same. Therefore, the treatment for children needs to constantly improve and enhance based on clinical trials conducted on children population. However, the best interests of the child should be a primary consideration.

According to the Convention on the Rights of the Child adopted by the UN General Assembly in 20 November 1989, the children have the same rights as adults. Thus, clinical trials on children should meet the same requirements needed for such trials on adults. However, due to children's vulnerability, they require special care and additional protection of their interests. It is essential to obtain informed consent, assess the risks to the child and minimise the fear and pain during the study.

There are two main concepts on the child's participation in a clinical trial:


For the first time, the term assent is mentioned in the Declaration of Helsinki, which states that when a subject deemed legally incompetent, such as a minor child, is able to give assent to decisions about participation in research, the investigator must obtain that assent in addition to the consent of the legally authorised representative [5].

Prior including a child into a clinical trial, his assent needs to be obtained. If such is missing, this fact, along with reasonable explanations of the same, needs to be noted in the Informed Consent of child's parents or legally authorised representative. Child's assent alone is not sufficient; it should always be accompanied with the informed consent of the parents. If a child reaches age of legal competency during the trial, his informed consent should be obtained and enclosed to the study documentation.

However, the degree of child's involvement in the decision depends on its age and maturity. Ethical committee can determine the age of the child when it can give consent to participate. This decision should comply with the local laws. Only the child's age, however, is not determinative of whether it is capable of giving consent to participate. The level of development, intellectual ability and experience may also be decisive. In all cases, trial information provided to a child needs to be adapted to its age and mental maturity.

The ethical expertise usually assesses and determines the risks and the benefits of clinical trials. The main principle is that the best interests of the child shall be a primary consideration. In practise, risk assessment on children depends on many factors. For example, taking a small quantity of blood from a child suffering from haemophilia creates risk, significantly exceeding the minimum. Children suffering from a chronic disease usually perceive easier various medical treatments. So they are at less risk compared to children who have no similar experience in illness.

During clinical trials on children, it is important to reduce and mitigate painful manipulations, by applying effective methods of pain reduction—usage of corresponding equipment and personnel trained or experienced in working with children.

Clinical studies on minors would also include some additional requirements:

