1. Randomized controlled trial (RCT): This is one of the most basic and reliable clinical trial types. Participants were randomly assigned to the experimental group and the control group, and the efficacy of drugs or treatments was evaluated through controlled experiments.
2. Prospective cohort study: This is a typical observational study. By reviewing and systematically tracking the disease process of participants, the risk factors and protective factors were explored, and the results were statistically analyzed.
3. Case-control study: It is also a typical observational study, taking the sick people and the non-sick people as the control group, comparing the causal relationship between the two groups, and discussing the influence of risk factors and protective factors on the condition.
4. Cross test: also known as cross test, it is to explore the influence of different environments or factors on the treatment results by giving the same object different treatments or multiple treatments.
5. Actual trial or retrospective trial: clinical observation based on medical institutions, medical records, databases or original samples.
6. Organizational intervention experiment: also known as organizational intervention experiment, is an experiment to improve the knowledge, skills and attitude of medical staff.
In short, according to the purpose and needs of the study, the types and methods of clinical trials will be very different, and each type of trial also has its advantages and limitations.