Clinical trial in the context of Reproducibility

Neurology (from Greek: νεῦρον (neûron), "string, nerve" and the suffix -logia, "study of") is the branch of medicine dealing with the diagnosis and treatment of all categories of conditions and disease involving the nervous system, which comprises the brain, the spinal cord and the peripheral nerves. Neurological practice relies heavily on the field of neuroscience, the scientific study of the nervous system, using various techniques of neurotherapy.

A neurologist is a physician specializing in neurology and trained to investigate, diagnose and treat neurological disorders. Neurologists diagnose and treat myriad neurologic conditions, including stroke, epilepsy, movement disorders such as Parkinson's disease, brain infections, autoimmune neurologic disorders such as multiple sclerosis, sleep disorders, brain injury, headache disorders like migraine, tumors of the brain and dementias such as Alzheimer's disease. Neurologists may also have roles in clinical research, clinical trials, and basic or translational research. Neurology is a nonsurgical specialty, its corresponding surgical specialty is neurosurgery.

Medical research (or biomedical research), also known as health research, refers to the process of using scientific methods with the aim to produce knowledge about human diseases, the prevention and treatment of illness, and the promotion of health.

Medical research encompasses a wide array of research, extending from "basic research" (also called bench science or bench research), – involving fundamental scientific principles that may apply to a preclinical understanding – to clinical research, which involves studies of people who may be subjects in clinical trials. Within this spectrum is applied research, or translational research, conducted to expand knowledge in the field of medicine.

A baseline in science (including medicine) is the initial conditions found by observation and measurement at the beginning of a survey or clinical trial or which is used for comparison with later data collected during or after the survey or trial to identify and measure changes, often with the intention of assessing the effects of a treatment or procedure.

In environmental science a baseline study is necessary to be able to accurately determine impact by monitoring the environment and comparing the changing situation with the initial conditions after development has occurred. In some cases, baseline information already be available from previous surveys, but it may be necessary to gather data in the field.

COVID-19 drug development is the research process to develop preventative therapeutic prescription drugs that would alleviate the severity of coronavirus disease 2019 (COVID-19). From early 2020 through 2021, several hundred drug companies, biotechnology firms, university research groups, and health organizations were developing therapeutic candidates for COVID-19 disease in various stages of preclinical or clinical research (506 total candidates in April 2021), with 419 potential COVID-19 drugs in clinical trials, as of April 2021.

As early as March 2020, the World Health Organization (WHO), European Medicines Agency (EMA), US Food and Drug Administration (FDA), and the Chinese government and drug manufacturers were coordinating with academic and industry researchers to speed development of vaccines, antiviral drugs, and post-infection therapies. The International Clinical Trials Registry Platform of the WHO recorded 536 clinical studies to develop post-infection therapies for COVID-19 infections, with numerous established antiviral compounds for treating other infections under clinical research to be repurposed.

In drug development, preclinical development (also termed preclinical studies or nonclinical studies) is a stage of research that begins before clinical trials (testing in humans) and during which important feasibility, iterative testing and drug safety data are collected, typically in laboratory animals.

The main goals of preclinical studies are to determine a starting, safe dose for first-in-human study and assess potential toxicity of the product, which typically include new medical devices, prescription drugs, and diagnostics.

Alternative medicine refers to practices that aim to achieve the healing effects of conventional medicine, but that typically lack biological plausibility, testability, repeatability, or supporting evidence of effectiveness. Such practices are generally not part of evidence-based medicine. Unlike modern medicine, which employs the scientific method to test plausible therapies by way of responsible and ethical clinical trials, producing repeatable evidence of either effect or of no effect, alternative therapies reside outside of mainstream medicine and do not originate from using the scientific method, but instead rely on testimonials, anecdotes, religion, tradition, superstition, belief in supernatural "energies", pseudoscience, errors in reasoning, propaganda, fraud, or other unscientific sources. Frequently used terms for relevant practices are New Age medicine, pseudo-medicine, unorthodox medicine, holistic medicine, fringe medicine, and unconventional medicine, with little distinction from quackery.

Some alternative practices are based on theories that contradict the established science of how the human body works; others appeal to the supernatural or superstitions to explain their effect or lack thereof. In others, the practice has plausibility but lacks a positive risk–benefit outcome probability. Research into alternative therapies often fails to follow proper research protocols (such as placebo-controlled trials, blind experiments and calculation of prior probability), providing invalid results. History has shown that if a method is proven to work, it eventually ceases to be alternative and becomes mainstream medicine.

Beneficence in general means "active well-doing". Duties of beneficence form a part of various religious and secular ethical theories. As an applied ethical concept relating to research, beneficence means that researchers should have the welfare of the research participant as a goal of any clinical trial or other research study. The antonym of this term, maleficence, describes a practice that opposes the welfare of any research participant. According to the Belmont Report, researchers are required to follow two moral requirements in line with the principle of beneficence: do not harm, and maximize possible benefits for research while minimizing any potential harm on others.

The idea that medical professionals and researchers would always practice beneficence seems natural to most patients and research participants, but in fact, every health intervention or research intervention has potential to harm the recipient. There are many different precedents in medicine and research for conducting a cost–benefit analysis and judging whether a certain action would be a sufficient practice of beneficence, and the extent to which treatments are acceptable or unacceptable is under debate.

Human subjects research is systematic, scientific investigation that can be either interventional (a "trial") or observational (no "test article") and involves human beings as research subjects, commonly known as test subjects. Human subjects research can be either medical (clinical) research or non-medical (e.g., social science) research. Systematic investigation incorporates both the collection and analysis of data in order to answer a specific question. Medical human subjects research often involves analysis of biological specimens, epidemiological and behavioral studies and medical chart review studies. (A specific, and especially heavily regulated, type of medical human subjects research is the "clinical trial", in which drugs, vaccines and medical devices are evaluated.) On the other hand, human subjects research in the social sciences often involves surveys which consist of questions to a particular group of people. Survey methodology includes questionnaires, interviews, and focus groups.

Human subjects research is used in various fields, including research into advanced biology, clinical medicine, nursing, psychology, sociology, political science, and anthropology. As research has become formalized, the academic community has developed formal definitions of "human subjects research", largely in response to abuses of human subjects.

Cancer research is research into cancer to identify causes and develop strategies for prevention, diagnosis, treatment, and cure.

Cancer research ranges from epidemiology, molecular bioscience to the performance of clinical trials to evaluate and compare applications of the various cancer treatments. These applications include surgery, radiation therapy, chemotherapy, hormone therapy, immunotherapy and combined treatment modalities such as chemo-radiotherapy. Starting in the mid-1990s, the emphasis in clinical cancer research shifted towards therapies derived from biotechnology research, such as cancer immunotherapy and gene therapy.

Studies that are in vivo (Latin for "within the living"; often not italicized in English) are those in which the effects of various biological entities are tested on whole, living organisms or cells, usually animals, including humans, and plants, as opposed to a tissue extract or dead organism.

Examples of investigations in vivo include: the pathogenesis of disease by comparing the effects of bacterial infection with the effects of purified bacterial toxins; the development of non-antibiotics, antiviral drugs, and new drugs generally; and new surgical procedures. Consequently, animal testing and clinical trials are major elements of in vivo research. In vivo testing is often employed over in vitro because it is better suited for observing the overall effects of an experiment on a living subject. In drug discovery, for example, verification of efficacy in vivo is crucial, because in vitro assays can sometimes yield misleading results with drug candidate molecules that are irrelevant in vivo (e.g., because such molecules cannot reach their site of in vivo action, for example as a result of rapid catabolism in the liver).

In vitro (meaning in glass, or in the glass) studies are performed with cells or biological molecules outside their normal biological context. Colloquially called "test-tube experiments", these studies in biology and its subdisciplines are traditionally done in labware such as test tubes, flasks, Petri dishes, and microtiter plates. Studies conducted using components of an organism that have been isolated from their usual biological surroundings permit a more detailed or more convenient analysis than can be done with whole organisms; however, results obtained from in vitro experiments may not fully or accurately predict the effects on a whole organism. In contrast to in vitro experiments, in vivo studies are those conducted in living organisms, including humans, known as clinical trials, and whole plants.

A pragmatic clinical trial (PCT), sometimes called a practical clinical trial (PCT), is a clinical trial that focuses on correlation between treatments and outcomes in real-world health system practice rather than focusing on proving causative explanations for outcomes, which requires extensive deconfounding with inclusion and exclusion criteria so strict that they risk rendering the trial results irrelevant to much of real-world practice.

Clinical study design is the formulation of clinical trials and other experiments, as well as observational studies, in medical research involving human beings and involving clinical aspects, including epidemiology . It is the design of experiments as applied to these fields. The goal of a clinical study is to assess the safety, efficacy, and / or the mechanism of action of an investigational medicinal product (IMP) or procedure, or new drug or device that is in development, but potentially not yet approved by a health authority (e.g. Food and Drug Administration). It can also be to investigate a drug, device or procedure that has already been approved but is still in need of further investigation, typically with respect to long-term effects or cost-effectiveness.

Some of the considerations here are shared under the more general topic of design of experiments but there can be others, in particular related to patient confidentiality and medical ethics.

In many countries, the term principal investigator (PI) refers to the holder of an independent grant and the lead researcher for the grant project, usually in the sciences, such as a laboratory study or a clinical trial. The phrase is also often used as a synonym for "head of the laboratory" or "research group leader". While the expression is common in the sciences, it is used widely for the person or persons who make final decisions and supervise funding and expenditures on a given research project.

A co-investigator (Co-I) assists the principal investigator in the management and leadership of the research project. There may be a number of co-investigators supporting a PI.

The Cochrane Library (named after Archie Cochrane) is a collection of databases in medicine and other healthcare specialties provided by Cochrane and other organizations. At its core is the collection of Cochrane Reviews, a database of systematic reviews and meta-analyses that summarize and interpret the results of medical research. The Cochrane Library aims to make the results of well-conducted clinical trials readily available and is a key resource in evidence-based medicine.