An experiment is a procedure carried out to support, refute, or validate a hypothesis. Experiments provide insight into cause-and-effect by demonstrating what outcome occurs when a particular factor is manipulated. Experiments vary greatly in goal and scale, but always rely on repeatable procedure and logical analysis of the results. There also exists natural experimental studies.
Clinical trials are experiments or observations done in clinical research. Such prospective biomedical or behavioral research studies on human participants are designed to answer specific questions about biomedical or behavioral interventions, including new treatments and known interventions that warrant further study and comparison. Clinical trials generate data on safety and efficacy. They are conducted only after they have received health authority/ethics committee approval in the country where approval of the therapy is sought. These authorities are responsible for vetting the risk/benefit ratio of the trial – their approval does not mean that the therapy is 'safe' or effective, only that the trial may be conducted.
A nocebo effect is said to occur when negative expectations of the patient regarding a treatment cause the treatment to have a more negative effect than it otherwise would have. For example, when a patient anticipates a side effect of a medication, they can suffer that effect even if the "medication" is actually an inert substance. The complementary concept, the placebo effect, is said to occur when positive expectations improve an outcome. Both placebo and nocebo effects are presumably psychogenic, but they can induce measurable changes in the body. One article that reviewed 31 studies on nocebo effects reported a wide range of symptoms that could manifest as nocebo effects including nausea, stomach pains, itching, bloating, depression, sleep problems, loss of appetite, sexual dysfunction and severe hypotension. Mental states such as beliefs and expectations can strongly influence the outcome of disease, the experience of pain, and even success of surgery.
A vaccine trial is a clinical trial that aims at establishing the safety and efficacy of a vaccine prior to it being licensed.
A scientific control is an experiment or observation designed to minimize the effects of variables other than the independent variable. This increases the reliability of the results, often through a comparison between control measurements and the other measurements. Scientific controls are a part of the scientific method.
The number needed to treat (NNT) is an epidemiological measure used in communicating the effectiveness of a health-care intervention, typically a treatment with medication. The NNT is the average number of patients who need to be treated to prevent one additional bad outcome. It is defined as the inverse of the absolute risk reduction, and computed as , where is the incidence in the treated (exposed) group, and is the incidence in the control (unexposed) group.
Assay sensitivity is a property of a clinical trial defined as the ability of a trial to distinguish an effective treatment from a less effective or ineffective intervention. Without assay sensitivity, a trial is not internally valid and is not capable of comparing the efficacy of two interventions.
A clinical control group is a group of individuals, involved in a healthcare experimentation, who do not receive the treatment, in order to determine the effectiveness of the drug, supplement or treatment being tested.
The average treatment effect (ATE) is a measure used to compare treatments in randomized experiments, evaluation of policy interventions, and medical trials. The ATE measures the difference in mean (average) outcomes between units assigned to the treatment and units assigned to the control. In a randomized trial, the average treatment effect can be estimated from a sample using a comparison in mean outcomes for treated and untreated units. However, the ATE is generally understood as a causal parameter that a researcher desires to know, defined without reference to the study design or estimation procedure. Both observational studies and experimental study designs with random assignment may enable one to estimate an ATE in a variety of ways.
Treatment of chronic fatigue syndrome (CFS) is variable and uncertain, and the condition is primarily managed rather than cured.
Boceprevir is a protease inhibitor used to treat hepatitis caused by hepatitis C virus (HCV) genotype 1. It binds to the HCV nonstructural protein 3 active site.
A glossary of terms used in clinical research.
The following outline is provided as an overview of and topical guide to clinical research:
Placebo-controlled studies are a way of testing a medical therapy in which, in addition to a group of subjects that receives the treatment to be evaluated, a separate control group receives a sham "placebo" treatment which is specifically designed to have no real effect. Placebos are most commonly used in blinded trials, where subjects do not know whether they are receiving real or placebo treatment. Often, there is also a further "natural history" group that does not receive any treatment at all.
The word placebo was used in a medicinal context in the late 18th century to describe a "commonplace method or medicine" and in 1811 it was defined as "any medicine adapted more to please than to benefit the patient". Although this definition contained a derogatory implication, it did not necessarily imply that the remedy had no effect.
LY-404,039, also known as pomaglumetad, is an amino acid analog drug that acts as a highly selective agonist for the metabotropic glutamate receptor group II subtypes mGluR2 and mGluR3. Pharmacological research has focused on its potential antipsychotic and anxiolytic effects. LY-404,039 is intended as a treatment for schizophrenia and other psychotic and anxiety disorders by modulating glutamatergic activity and reducing presynaptic release of glutamate at synapses in limbic and forebrain areas relevant to these disorders. Human studies investigating therapeutic use of LY-404,039 have focused on the prodrug LY-2140023, a methionine amide of LY-404,039 (also called pomaglumetad methionil or LY-2140023 monohydrate) since LY-404,039 exhibits low oral absorption and bioavailability in humans.
Fostamatinib, sold under the brand name Tavalisse, is a medication approved by the U.S. Food and Drug Administration since 2018 for the treatment of chronic immune thrombocytopenia (ITP). The drug is administered orally as a disodium hexahydrate salt, and is a prodrug of the active compound tamatinib (R-406), which is an inhibitor of the enzyme spleen tyrosine kinase (Syk), hence it is an syk inhibitor.
Ixekizumab also known under trade name Taltz is an injectable drug for the treatment of autoimmune diseases. Chemically, it is a form of a humanized monoclonal antibody. The substance acts by blocking interleukin 17A, reducing inflammation.
Demcizumab is a humanized monoclonal antibody which is used to treat patients with pancreatic cancer or non-small cell lung cancer. Demcizumab has completed phase 1 trials and is currently undergoing phase 2 trials. Demcizumab was developed by OncoMed Pharmaceuticals in collaboration with Celgene.
