There are 4 phases in the current clinical trials. In the first phase of a clinical trial, the proposed drug safety is tested  1/1 and those tests last for more than two months and usually involve a number of healthy volunteers who are paid to be
part of the trial. The aim of this study is to observe how would the human body react to the tested drug or device  and different dosages and intensity are included. The statistics showed the 70% of drugs/devices pass this phase.

The second phase tests the efficiency of the drug/device and usually lasts from several months to about two years.  The number of volunteers in this phase jumps to hundreds of people. Many of the studies conducted in this phase are  random and they are usually applied on two groups of people. The first group takes a dosage of the experimental  drug while the other group takes a standard medication while thinking that they're taking the actual experimental drug.  The researchers are unaware of the actual experiment too. This is done to observe the psychological effects and  human behavior. By gathering this information, the investigators deliver comparative information about the safety and  efficiency of the drug or device to pharmaceutical companies and the FDA. About 33.3% of the tested drugs or  devices go through phase I and II.

The third phase of clinical trials are randomized as well and they usually have several hundred to thousands of  volunteers. In this phase the scale of the testing is way bigger and testing a drug or device would take a minimum of  2 years or even more. By having a large number of volunteers, the investigators get a better understanding and more  details on the effectiveness, benefits, and the possible harmful or unwanted reactions. When a drug/device passes this  phase, pharmaceutical companies are able to request approval from the FDA to start marketing the drug.

The fourth phase and the last phase is named Post Marketing Surveillance Trial which is a study that starts after the  drug or the device is available for consumer use. There are three main objectives of this study, first pharmaceutical  companies compare the new drug or device to other existing drugs. Secondly, they observe the long-term effectiveness  of the drug on the patient's progress and life quality. Third, they determine the cost-effectiveness of the new drug  compared to existing or popular drugs. The results of this phase can lead to having the new drug or device taken off  the market, or some restrictions may apply when using the new medicine or tool.

The cost of running these clinical trials is now higher than ever, with expenses running at between $30 million and $70 million for a single Phase III trial.

Integrating Blockchain technology with Clinical trials will give the following benefits:

1: Security to the clinical data and protection from any alteration 

2: An immutable record that will show data and all changes in a consistent matter   

3: Past data that will show the complete history of clinical information

4: peer-2peer payments via smart contracts

5: Operation interoperability between several systems and data formats

6: Protection of privacy is possible. Blockchain technology allows adding and verifying records to an immutable ledger  without compromising the content of each record. 

7: Control of access to the content of each record by using encryption keys. The public key shows that the record  exists while the private key gives access to the content of the record.