Final answer:
A randomized controlled trial (RCT) is the study design predominantly used in first-in-human research, employing randomization and often blinding with placebos to objectively evaluate treatment effects.
Step-by-step explanation:
The type of study design generally used in first-in-human research studies is the randomized controlled trial (RCT). This method involves randomly assigning participants to either the experimental group or control group to ensure any observed effects are due to the intervention itself and not other factors. A hallmark of RCTs is the use of placebos to blind participants to the treatment they receive, thus eliminating the power of suggestion. Additionally, this study design often employs double blinding, where neither the participants nor the researchers know who belongs to which group, further reducing bias.
Randomized-sequenced double blind, placebo-controlled crossover clinical studies and randomized, open-label, crossover studies are specific types of RCTs with particular characteristics, used to rigorously assess the efficacy of a treatment under controlled conditions.
Understanding experimental design and ethics is crucial in RCTs to generate reliable data. Researchers must meticulously plan the study so that the only differences between treatment groups are those imposed by the study's interventions.