Clinical trial

A clinical trial, also known as a clinical study, is conducted with test persons or patients to test drugs or medical devices for their efficacy and safety. Clinical trials answer questions from clinical research and improve medical treatment.

There are many different study designs of clinical trials. In principle, a distinction is made between the experimental study in which an intervention is conducted and the non-interventional study (NIS).

In the experimental - interventional study, a drug or medical device is tested, which is carried out according to the protocol or study protocol. Experimental studies are always prospective and may include randomisation and blinding.

In randomised controlled trials (RCT), there are at least two study arms to which study participants are randomly assigned. In randomised trials, hypotheses are tested, whereby a causality between the intervention and the therapeutic outcome can be established. Randomized studies therefore have a high internal validity, so that the efficacy of the test product can be reliably proven.

In non-interventional studies, also known as observational studies, there are no interventions, but rather documentation of treatments that are carried out without modification by the study. Non-interventional studies can be designed as cohort studies, case-control studies or cross-sectional studies. Non-interventional studies have a high external validity ("real life") and provide information about the actual results of therapies. Non-interventional studies can be prospective or retrospective.

In clinical research, developments of medical devices and drugs go through various phases before approval is granted. For medicinal products, the following stages are distinguished:

• In phase 0 studies (microdosing), which are not required by law, very low doses of an active substance, which are significantly below the efficacy threshold, are tested on volunteers in a low number of cases (approx. 10 - 15 volunteers).
• In Phase I studies, active substances are tested for the first time on approx. 20 - 80 healthy volunteers, whereby the transferability from animal experiments to humans is proven. The aim is to prove the safety and tolerability of the drug and to investigate its pharmacokinetics. In the case of therapies for serious diseases, where the substances can cause severe side effects for healthy volunteers, tumour patients can also be recruited, e.g. for the treatment of new chemotherapeutic agents.
• Phase II studies are clinical trials in which the active substance is used on patients for the first time (number of cases: approx. 50 - 200). Here, the positive effects, side effects and the best dose (dose finding) are investigated.
• Phase III studies are clinical studies in which the drug is tested in a larger patient population (150 patients or more). The aim is to prove the efficacy and safety in different patient groups.
• Phase IV studies are clinical studies after approval. The aim is to evaluate effects and side effects in a larger patient population and to establish a therapeutic threshold.

Terms used in clinical studies (in alphabetical order):

• adverse event
• Amendment
• Notified body
• notified body
• Bias
• Higher federal authorities
• Case Report Form (CRF)
• Clinical Investigator (investigator)
• Clinical Research Associate (CRA/ Clinical Monitor)
• Clinical Research Organization (CRO)
• Clinical Study Report (CSR)
• Clinical Trial (clinical study)
• CONSORT Statement
• Contract Research Organisation (CRO)
• Declaration of Helsinki
• German Register of Clinical Studies
• DIMDI (German Institute for Medical Documentation and Information)
• Dossier on the investigational medicinal product
• eCRF
• Declaration of consent
• End point
• Ethics Committee
• EudraCT
• Evidence level (evidence class)
• Calculation of the number of cases
• Feasibility Study (Feasibility Study)
• FDA - Food and Drug Administration
• Final Report (Final Report)
• Freiburg International Ethics Committee - feki
• Good Clinical Practice (GCP)
• Remuneration of investigators / study physicians
• IMPD - Investigator Medicinal Product Dossier
• Informed Consent Form (ICF)
• International Conference on Harmonisation (ICH)
• Investigator Initiated Trial - Investigator Initiated Study - IIT
• Investigator Meeting - Investigator meeting - Study meeting
• ISO 14155
• Jadad Score
• Jadad Scale
• Clinical study (clinical trial)
• Head of the clinical study(LKP)
• Feasibility Study
• Medical Products Act (MPG)
• Non-interventional study (NIS)
• Notified Body (Recognised Body)
• Benefit - Risk - Analysis
• OpenClinica
• Patient Consent Form
• Pharmacovigilance
• Test person
• Project management / project manager in clinical studies
• Investigator (Clinical Investigator)
• Investigational product
• Investigator meeting (study meeting)
• Quality assurance - Quality Assurance
• Quality Assurance (quality assurance)
• Query (Queries)
• Randomization
• Risk - benefit - analysis
• Robert Koch Institute
• Subjects in need of protection
• SecuTrial®
• Serious Adverse Event
• Sponsor
• Standard Operating Procedure (SOP)
• Study Nurse (study assistant)
• STROBE (STrengthening the Reporting of OBservational studies in Epidemiology)
• Trial Master File (TMF)
• Adverse event
• Vulnerable Subjects (subjects in need of protection)
• World Health Organization (WHO)
• XClinical
• Certifications in clinical research
• Target criterion