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Double-Blinded Clinical Studies: The gold standard for testing medicines.

The journey of double-blinded clinical trials from their origins with James Lind's study on scurvy to their modern-day use in drug trials.

Deepu Asok
Deepu Asok
2 min read
Double-Blinded Clinical Studies: The gold standard for testing medicines.
Photo by Christine Sandu / Unsplash

Table of Contents

The origin of the blinded trials.

In the late 1700s, a Scottish naval surgeon named James Lind conducted what is now considered one of the first recorded clinical studies. He was trying to find a cure for scurvy, a disease that was killing countless sailors on long sea voyages.

Lind's study was not double-blinded, as the concept had not yet been developed, but it was the start of a new era in medicine. He divided a group of sailors with scurvy into six groups and gave each group a different treatment, including vinegar, seawater, and a potion made from oranges and lemons.

To Lind's surprise, the sailors who received the citrus potion showed rapid improvement, while the others continued to suffer. This discovery eventually led to the understanding that scurvy was caused by a deficiency in vitamin C, and the treatment of choice became fresh fruits and vegetables.

Today, double-blinded clinical studies are a far cry from Lind's rudimentary experiments, but the principles remain the same. By removing bias from the equation, we can ensure that the treatments we use are safe and effective for everyone, not just those who may have a placebo effect.

The definition of a double-blinded study

A double-blinded study is a type of clinical trial where both the researchers and the participants are unaware of who is receiving the treatment being tested and who is receiving a placebo. The term "blinding" refers to the process of keeping participants and researchers "blind" to this information, meaning they don't know which group they belong to.

This is done to prevent bias in the results. When researchers know which participants are receiving the treatment, they may unintentionally give them more attention or care, leading to a placebo effect that could skew the results. Similarly, when participants know which group they are in, they may adjust their behavior or expectations, also potentially affecting the results.

Eliminating Bias in Clinical Trials

In a double-blinded study, participants are randomly assigned to either the treatment group or the placebo group, and the researchers do not know who is in which group. The treatment group receives the medication or treatment being tested, while the placebo group receives a fake treatment that looks and feels the same as the real one, but has no therapeutic effect.

Throughout the study, neither the participants nor the researchers know which group each participant belongs to. This information is only revealed after the study is complete and the data has been analyzed. Double-blinded studies are considered the gold standard for clinical trials because they eliminate bias and provide the most reliable results.

The ultimate goal in the scientific testing of medicines is to avoid human bias and subjectiveness in measuring their effectiveness. To achieve this goal, as Eric Topol, the renowned American cardiologist, and researcher said, "There is no alternative to a double-blind, randomized, placebo-controlled trial" which makes it the gold standard.

Clinical Trials