Everything you need to know about clinical trials

Everything you need to know about clinical trials

What are Clinical trials?

Recently the world was shaken by the Covid-19 and people are all afraid for the fear of life. Every now and then we are all bombarded by news of how the Covid-19 is creating havoc. We also know yet there is no medicine that acts like magic and cures the disease. Just the condition has made us all very hopeless. People are reading news about new medicines and vaccines. The news channels are projecting every minute detail like breaking news. Every few hours we find something failed or succeeded in some weird clinical tests never discussed so highlighted before. Here we will try to explain ‘what are clinical trials?’ as many of you want us to write about this information.

Well we all know medicine is a science! Science develops with research about the problems and finding out the solutions. The core property of science is it is always evolving and turns in the direction of the needs of people. It tries to satisfy the quench of the better life of mankind. So is true about medicine. Medicine is ever evolving science. It is guided by health and medical problems. It combines basic knowledge of human body function in health and disease combined with how the drugs can change these processes in a favourable manner.

But alas here in medicine we are dealing with live human beings and human society is guided by the ethics and laws too. Indeed in a way to make the human life in society better these aspects are needed too. Unlike combining inanimate machines and testing them to make a better machine here we are dealing with live human beings.

Here we will try to explain this meaning hidden between the lines. First we will list the main points which are needed for you to understand the concept then we will explain each in deep focus. Hope you find it useful and valuable.

  • Clinical trials and research.
  • What are types of clinical research?
  • Before doing clinical trials
  • What are phases of clinical trials?

Clinical Trials and research

“Clinical trials are research studies performed in people that are aimed at evaluating a medical, surgical, or behavioral intervention.” The clinical trials may also include studying behavioural changes and lab tests on humans. 

Doing such research on human beings involves ethical and legal issues and they need to be addressed to. So these trials are to be done with utmost care so that the subjects participating in it have the knowledge about it and they suffer least in the process.

Written in a single line it looks simple. It is just testing some new found drugs or vaccines or surgical intervention for effects and side effects. But it has deep meaning hidden between the lines.

What are types of clinical research?

Clinical research is mainly of two types 

  • Observational studies 
  • Interventional studies

Observational studies

These include observation of a group for certain factors at a moment or for prolonged period of life. These studies are needed to study a hypothesis. These studies determine whether the relation between a factor and end result is actual or it has occurred just by a chance.

Observational studies are 

  • Case control studies 
  • Cohort studies and 
  • Cross sectional studies

Case control studies

In this study the cases of a disease or condition are selected and a group of people having no disease or condition is selected. The given factor to be examined as a cause is observed and counted in both groups. Final result is concluded whether the given factor is more common in a group of people with disease compared to the group of people with no disease presenting to the general population.

Eg. To study whether smoking causes lung cancer you will consider hypothesis that ‘Smaking causes lung cancer’

Then you will select another group of people which is of comparable size and age, sex distribution representing general population.

Then you will ask about smoking history in both groups.

Then you will compare the results of both the groups.

You will examine the numbers with statistical tests.

You will determine whether smoking was really more common in people with lung disease than people representing the general population.

If smoking is significantly more common in people with lung cancer then you will state that there is strong association between smoking and lung cancer.

Though these studies tell us about strength of association we need further studies to examine the causal relationship.

Cohort studies

These are types of observational studies. Cohort is literally a group of people with similar characteristics. Like all people born in dec 2020.

Here we don’t have an end result but we have a hypothesis that a factor is associated with the end result. So we select groups of people with a factor and without a factor to be studied. We observe both the groups for a period of time and we study the result in both the groups.

Eg If you want to see whether smoking causes lung cancer, you will form a hypothesis that smoking causes lung cancer. Now you will select a group of people having a habit of smoking a similar characteristic and comparable group of people with no such habit.

Then you will observe them for a pre-decided time and then you will compare the number of people who got lung cancer in both groups.

You will see whether cohorts of smokers get lung cancer more commonly than non smokers.

You will compare the results statistically.

Finally how powerfully the association is supported is decided.

Cross sectional studies

These studies are used to save time and money. A population is examined for certain factors and the end result at the same time. These studies are also observational studies and they study multiple factors at the same time. They involve a large sample of subjects and used to study the power of association between a factor and end result in the community at the same time.

Interventional studies

These studies involve studying the actual treatment or preventive or surgical and behavioural change method in a population to reduce the disease. These studies may also involve studying effectiveness of the lab tests and radiological tests. These are sometimes referred to as clinical trials.

Clinical trials are aimed at

  • Treatment Research usually involves studying the measures taken to treat a condition. It may involve studying about a drug, a surgical treatment or behavioural changes aimed at treating the condition.
  • Prevention Research is aimed at preventing the disease and making life better. It may involve study of a drug used for prevention or a vaccine or diet and behavioural changes to prevent the disease.
  • Diagnostic Research involves making the diagnostic process more accurate and efficient in case of patient and clinician’s perspective. Better diagnostics can guide better treatment aimed at the problem. This involves studying lab tests and radiological tests to diagnose a condition.
  • Screening Research is different from diagnosis in a way screening is more easy and fast and may be inferior in accuracy. It may overdiagnose but do not miss the cases later on confirmed by diagnostic tests. These tests are needed to rapidly screen a population for a condition and without using difficult and costly tests on entire population which can be reserved for those who come positive in screening tests.
  • Quality of Life Research is aimed at studying how the treatment and interventions have helped the patients with chronic conditions in the long run. It studies o what extent life of people with chronic diseases have improved or worsened.
  • Genetic studies aim to improve the prediction of disorders by identifying and understanding how genes and illnesses may be related. Research in this area may explore ways in which a person’s genes make him or her more or less likely to develop a disorder. This may lead to development of tailor-made treatments based on a patient’s genetic make-up. 
  • Epidemiological studies seek to identify the patterns, causes, and control of disorders in groups of people. It may be closely related to and include observational studies as we have discussed earlier.

Before doing clinical trials

Clinical trials are some last phases for the approval of the drug or vaccine. Before that the vaccine or drug under study has to go through different phases of study also known as pre clinical trials.

The drug supposed to be effective is tested in different animals to see its effect. Some animals and other primates like monkeys, pigs or rats are used to observe the effects of the drug or the vaccine.

After rigorous study and getting permissions needed from the designated authority the drug is approved for use in clinical trials.

What are the phases of clinical trials?

Clinical trials are conducted in four phases. Let us explain them one by one.

Phase 1 Clinical trial

  • The aim of the phase 1 clinical trial involves studying the safety and safe dose and identifying the side effects.
  • This phase involves studying the drug or treatment or a vaccine for the first time in humans.
  • In this phase a small group of humans are chosen to study the drug of vaccine.
  • They are administered the vaccine or drugs and treatment after giving them complete information and taking their consent about participation in the study.
  • They are observed closely for a period of time and the conclusion is drawn about whether further tests can be safely done.

Phase 2 clinical trial

  • This is the stage after completion of phase 1 clinical trial.
  • This stage is started after the first stage found safety doses and side effects.
  • This phase further studies the safety of the drugs and side effects if any.
  • Since it includes the large group it gives the confirmation to the results of stage 1.
  • In this stage also participants are enrolled and given the drug or vaccine to be tested.
  • The due information about the nature of risk is informed in detail to the subjects.
  • Their consent is taken after providing them due information and participation is voluntary in nature.

Phase 3 Clinical trial

  • Here in the third phase of clinical trials the drug, test or vaccine is further tested after phase 2 clinical trial.
  • In this phase subjects are selected in very large number across the countries and of different sex and age groups and different race.
  • They are given due information of the drug or procedure and the informed voluntary consent is taken for the participation.
  • This phase is used to study the effectiveness of the treatment on a large scale.
  • Additionally, the side effect profile is monitored too.
  • In this phase the treatment under study can be compared with already available treatment.
  • After the result it is concluded whether the new found drug is better or comparable efficacy to the previous one or not.
  • This is the most important phase of the clinical trial and if this clinical trial suggests the new drug is safe and effective for the condition under study it is approved for use in the community.

Phase 4 clinical trials

  • Essentially phase 4 clinical trial takes place after the launch of the drug.
  • This is a post marketing clinical trial.
  • This clinical trial finds out the rare side effects of the medicine. Rare side effects being rare in occurrence they are found after using drug in millions of peoples.
  • This phase 4 clinical trial has also aimed at studying the impact of new drugs or vaccines on the community.
  • It also suggests whether current drug, medicine or treatment needs any improvement.

I hope this blogpost has cleared some doubts about clinical trials. You can ask further about it in the comment section. In further posts we will discuss up to what phases of clinical trials corona vaccines have made it. We hope soon we will get good news about vaccine as everyone is waiting.




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