Which of the following is a characteristic of Randomized-Controlled Trial (RCT)? (Select all that apply)

Randomized controlled trials (RCTs) are considered the gold standard because they use random assignment to allocate participants to intervention and control groups, minimizing selection bias and balancing known and unknown confounding factors. By comparing outcomes between groups, RCTs provide the most reliable evidence of causal relationships between treatments and effects. Their structured design, including blinding and control groups, enhances internal validity and allows for direct assessment of treatment efficacy.

A. to examine whether the proposed research is properly designed: Ensuring that research is properly designed is primarily the responsibility of the Institutional Review Board (IRB) or ethics committee. While investigators design the study, the formal evaluation of methodological soundness and ethical compliance is conducted by an independent review body.

B. to determine whether or not to participate in the research: Determining participation is the responsibility of the potential research subject, based on the principle of respect for persons. Through informed consent, individuals decide whether the potential risks and benefits are acceptable to them. This decision-making authority belongs to participants, not investigators.

C. to determine whether the risks that will be presented to subjects are justified: Under the principle of beneficence in the Belmont Report, investigators are responsible for conducting a thorough risk–benefit assessment. They must minimize potential harms and ensure that anticipated benefits justify any risks involved. This includes designing procedures that reduce exposure to unnecessary physical, psychological, or social harm.

D. All of the above: Although multiple parties share ethical responsibilities in research oversight, the investigator’s specific duty under beneficence focuses on assessing and justifying risks relative to benefits. Therefore, not all listed options fall under the investigator’s direct responsibility.