Evidence-based medicine in the context of "Conversion therapy"

The practice and study of medicine in Persia has a long and prolific history. The Iranian academic centers like Gundeshapur University (3rd century AD) were a breeding ground for the union among great scientists from different civilizations. These centers successfully followed their predecessors’ theories and greatly extended their scientific research through history. Persians were the first establishers of modern hospital system.

In recent years, some experimental studies have indeed evaluated medieval Iranian medical remedies using modern scientific methods. These studies raised the possibility of revival of traditional treatments on the basis of evidence-based medicine.

Evidence-based design (EBD) is the process of constructing a building or physical environment based on scientific research to achieve the best possible outcomes. Evidence-based design is especially important in evidence-based medicine, where research has shown that environment design can affect patient outcomes. It is also used in architecture, interior design, landscape architecture, facilities management, education, and urban planning. Evidence-based design is part of the larger movement towards evidence-based practices.

Metascience (also known as meta-research) is the use of scientific methodology to study science itself. Metascience seeks to increase the quality of scientific research and enhance its efficiency. It is also known as "research on research" and "the science of science", as it uses research methods to study how research is done and find where improvements can be made. Metascience concerns itself with all fields of research and has been described as "a bird's eye view of science". In the words of John Ioannidis, "Science is the best thing that has happened to human beings ... but we can do it better."

In 1966, an early meta-research paper examined the statistical methods of 295 papers published in ten high-profile medical journals. It found that "in almost 73% of the reports read ... conclusions were drawn when the justification for these conclusions was invalid." Meta-research in the following decades found many methodological flaws, inefficiencies, and poor practices in research across numerous scientific fields. Many scientific studies could not be reproduced, particularly in medicine and the soft sciences. The term "replication crisis" was coined in the early 2010s as part of a growing awareness of the problem.

Medicinal plants, also called medicinal herbs, have been discovered and used in traditional medicine practices since prehistoric times. Plants synthesize hundreds of chemical compounds for various functions, including defense and protection against insects, fungi, diseases, against parasites and herbivorous mammals.

The earliest historical records of herbs are found from the Sumerian civilization, where hundreds of medicinal plants including opium are listed on clay tablets, c. 3000 BC. The Ebers Papyrus from ancient Egypt, c. 1550 BC, describes over 850 plant medicines. The Greek physician Dioscorides, who worked in the Roman army, documented over 1000 recipes for medicines using over 600 medicinal plants in De materia medica, c. 60 AD; this formed the basis of pharmacopoeias for some 1500 years. Drug research sometimes makes use of ethnobotany to search for pharmacologically active substances, and this approach has yielded hundreds of useful compounds. These include the common drugs aspirin, digoxin, quinine, and opium. The compounds found in plants are diverse, with most in four biochemical classes: alkaloids, glycosides, polyphenols, and terpenes. Few of these are scientifically confirmed as medicines or used in conventional medicine.

Evidence-based practice is the idea that occupational practices ought to be based on scientific evidence. The movement towards evidence-based practices attempts to encourage and, in some instances, require professionals and other decision-makers to pay more attention to evidence to inform their decision-making. The goal of evidence-based practice is to eliminate unsound or outdated practices in favor of more-effective ones by shifting the basis for decision making from tradition, intuition, and unsystematic experience to firmly grounded scientific research. The proposal has been controversial, with some arguing that results may not specialize to individuals as well as traditional practices.

Evidence-based practices have been gaining ground since the introduction of evidence-based medicine and have spread to the allied health professions, education, management, law, public policy, architecture, and other fields. In light of studies showing problems in scientific research (such as the replication crisis), there is also a movement to apply evidence-based practices in scientific research itself. Research into the evidence-based practice of science is called metascience.

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.

Faith healing is the practice of prayer and gestures (such as laying on of hands) that are believed by some to elicit divine intervention in spiritual and physical healing, especially the Christian practice. Believers assert that the healing of disease and disability can be brought about by religious faith through prayer or other rituals that, according to adherents, can stimulate a divine presence and power. Religious belief in divine intervention does not depend on empirical evidence of an evidence-based outcome achieved via faith healing. Virtually all scientists and philosophers dismiss faith healing as pseudoscience.

Claims that "a myriad of techniques" such as prayer, divine intervention, or the ministrations of an individual healer can cure illness have been popular throughout history. There have been claims that faith can cure blindness, deafness, cancer, HIV/AIDS, developmental disorders, anemia, arthritis, corns, defective speech, multiple sclerosis, skin rashes, total body paralysis, and various injuries. Recoveries have been attributed to many techniques commonly classified as faith healing. It can involve prayer, a visit to a religious shrine, or simply a strong belief in a supreme being.