Clinical trials

From The School of Biomedical Sciences Wiki
Revision as of 15:28, 18 October 2018 by 170245621 (Talk | contribs)
Jump to: navigation, search

What are clinical trials?

Clinical trials are research studies designed to evaluate forms of healthcare interventions such as drugs in order to deem them safe and effective for human use [1].

History and the later implications

The use of humans in clinical trials can be seen when the Nazi doctors carried out medical experimentation on prisoners of war during WW2. The subsequent trials of war criminals led to the Nuremberg Code, which was one of the first ethical guidelines in which researchers should follow. It has key 10 principles, these are [2]:

  1. Voluntary consent is essential
  2. The research should be for the good of society as a whole
  3. Research should be based on previous knowledge e.g. animal studies
  4. Avoid unnecessary physical and mental suffering
  5. Research should be avoided if death will occur
  6. Risk should be assessed and should never exceed the benefits
  7. Should take place in adequate facilities
  8. Conducted by qualified personnel
  9. Withdrawal must be explained to participants
  10. Research should be halted following risk or injury

There are various randomisation techniques used to assign patients to groups. This can be a simple coin toss to the block method of assigning numbers to each possible combination of group or the use of stratified sampling based on e.g. gender, age, treatment location if the groups need to match in size or variability. There are many practical considerations when ensuring a clinical trial is unbiased such as blinding or double blinding and ensuring the allocation of groups is not done by anyone personally involved with the subjects of the trial.

The first randomised control trial occured in 1948, and was a major histocompatibility complex streptomycin trial. This trial aimed at investigating treatment for pulmonary tuberculosis. Sealed envelopes were utilised to randomly allocate patients to groups, and blinding was applied[3]


  1. National Heart, Lung and Blood Institute, What are Clinical Trials?, n,d, [cited 22/10/17]; Available from
  2. Imarc, Natalie Jarmusik, Nuremberg Code (1947), 19/11/14, [cited 22/10/17]; Available from
  3. Streptomycin Treatment of Pulmonary Tuberculosis Br Med J. 1948 Oct 30; 2(4582): 769–782.


Personal tools