What does the term "blind" refer to in clinical trials?

In clinical trials, the term "blind" typically refers to a design where participants are unaware of the treatment they are receiving. This approach is essential for minimizing bias, as it reduces the potential for participants' expectations or knowledge of their treatment to influence their responses or perceived outcomes. When participants do not know whether they are receiving the active treatment or a placebo, it helps ensure that the data collected is more objective and reflects the true efficacy and safety of the intervention under investigation.

This blinding can enhance the validity of the trial results, as it helps mitigate placebo effects and subjectivity in reporting outcomes. Meanwhile, designs where only investigators know the treatment versus those that involve full transparency to both participants and investigators have different implications for bias and data interpretation, highlighting the importance of maintaining an unbiased environment for accurate conclusions.