Inclusion And Exclusion Criteria, Key To Validity And Ethics Of Scientific Studies

Scientific study illustration (Pexels/@fauxels)

YOGYAKARTA - The selection of participants is very crucial in research, especially research involving human subjects such as clinical trials. The selection process should not be arbitrary, but must follow strict guidelines known as inclusion and exclusion criteria.

The combined inclusion and exclusion criteria form what is referred to as a feasibility criterion or criterion that determines who can and cannot participate in a study.

Launching Scribbr, the inclusion criterion is a characteristic or requirement that must be met by prospective participants in order to be included in a study. This criterion is set to ensure that the population studied is homogeneous and relevant to research purposes.

For example, in a chronic heart failure treatment study, researchers may establish inclusion criteria such as:

Inclusion criteria like these help researchers get more consistent data, as all participants are in the same ground state.

Meanwhile, exclusion criteria are used to exclude certain individuals from participation in the study, although they may meet inclusion criteria. These criteria are made to prevent factors that can interfere with data reliability or endanger the safety of participants.

Examples of exclusion criteria in heart failure studies can include:

By properly establishing exclusion criteria, researchers can reduce disruptive variables and ensure the safety and ethics of the study.

Determination of inclusion and exclusion criteria is not only a matter of efficiency, but also a matter of scientific validity and ethical responsibility. Without clear criteria, research can lose internal validity (cause to cause in the study) or external validity (generalization ability of the results).

For example, if someone who uses sleeping pills participates in a study of insomnia without being classified as an exclusion criterion, then the results of the study can become biased. Likewise, including participants with unclear diagnosis will obscure the interpretation of the data.

In addition, this criterion helps protect vulnerable groups. Minors, pregnant women, or people with cognitive disorders are often excluded from clinical trials to avoid unbalanced exploitation or risks. Researchers are required to ensure that each participant really understands the information provided and agrees voluntarily before being involved.

An example of a good formulation for the inclusion criterion can read: "Subjects that have been diagnosed suffer from insomnia by doctors and experience at least 3 nights per week over the past 3 months." This formula is more measurable and objective than just mentioning subjects experiencing insomnia.

The formulation of a good exclusion criterion can read: "Partitions will be excluded if they are taking drugs that can affect sleep patterns or other prescription drugs that could interfere with the outcome of the study." This helps researchers maintain data integrity and avoid unwanted outside variables.

Based on the explanation above, it can be seen that inclusion and exclusion criteria are the foundation in designing research that is not only valid, but also ethical. This criterion determines who deserves to be a participant and who needs to be excluded, with the aim of optimizing data quality, maintaining security, and upholding research ethics.

In the context of clinical trials and other experiments, understanding and applying these criteria appropriately will help researchers answer research questions in an accurate, responsible and scientifically accountable way.