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Number Needed To Treat
The number needed to treat (NNT) or number needed to treat for an additional beneficial outcome (NNTB) is an epidemiology, 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 1/(I_u - I_e), where I_u is the incidence in the control (unexposed) group, and I_e is the incidence in the treated (exposed) group. This calculation implicitly assumes monotonicity, that is, no individual can be harmed by treatment. The modern approach, based on counterfactual conditional, counterfactual conditionals, relaxes this assumption and yields bounds on NNT. A type of effect size, the NNT was described in 1988 by McMaster University's Laupacis, Sackett and Roberts. While theoretically, the ideal NNT is 1, where everyone improves with treatm ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Epidemiology
Epidemiology is the study and analysis of the distribution (who, when, and where), patterns and Risk factor (epidemiology), determinants of health and disease conditions in a defined population, and application of this knowledge to prevent diseases. It is a cornerstone of public health, and shapes policy decisions and evidence-based practice by identifying Risk factor (epidemiology), risk factors for disease and targets for preventive healthcare. Epidemiologists help with study design, collection, and statistical analysis of data, amend interpretation and dissemination of results (including peer review and occasional systematic review). Epidemiology has helped develop methodology used in clinical research, public health studies, and, to a lesser extent, basic research in the biological sciences. Major areas of epidemiological study include disease causation, transmission (medicine), transmission, outbreak investigation, disease surveillance, environmental epidemiology, forensic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cholesterol
Cholesterol is the principal sterol of all higher animals, distributed in body Tissue (biology), tissues, especially the brain and spinal cord, and in Animal fat, animal fats and oils. Cholesterol is biosynthesis, biosynthesized by all animal Cell (biology)#Eukaryotic cells, cells and is an essential structural and cholesterol signaling, signaling component of animal cell membranes. In vertebrates, hepatocyte, hepatic cells typically produce the greatest amounts. In the brain, astrocytes produce cholesterol and transport it to neurons. It is absent among prokaryotes (bacteria and archaea), although there are some exceptions, such as ''Mycoplasma'', which require cholesterol for growth. Cholesterol also serves as a Precursor (chemistry), precursor for the biosynthesis of steroid hormones, bile acid and vitamin D. Elevated levels of cholesterol in the blood, especially when bound to low-density lipoprotein (LDL, often referred to as "bad cholesterol"), may increase the risk of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Drug Discovery
In the fields of medicine, biotechnology, and pharmacology, drug discovery is the process by which new candidate medications are discovered. Historically, drugs were discovered by identifying the active ingredient from traditional remedies or by serendipitous discovery, as with penicillin. More recently, chemical libraries of synthetic small molecules, natural products, or extracts were screened in intact cells or whole organisms to identify substances that had a desirable therapeutic effect in a process known as classical pharmacology. After sequencing of the human genome allowed rapid cloning and synthesis of large quantities of purified proteins, it has become common practice to use high throughput screening of large compounds libraries against isolated biological targets which are hypothesized to be disease-modifying in a process known as reverse pharmacology. Hits from these screens are then tested in cells and then in animals for efficacy. Modern drug discovery i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pharmacoeconomics
Pharmacoeconomics refers to the scientific discipline that compares the value of one pharmaceutical drug or drug therapy to another. It is a sub-discipline of health economics. A pharmacoeconomic study evaluates the cost (expressed in monetary terms) and effects (expressed in terms of monetary value, efficacy or enhanced quality of life) of a pharmaceutical product. Pharmacoeconomic studies serve to guide optimal healthcare resource allocation, in a standardized and scientifically grounded manner. Economic evaluation Pharmacoeconomics centers on the economic evaluation of pharmaceuticals, and can use cost-minimization analysis, cost-benefit analysis, cost-effectiveness analysis or cost-utility analysis. Quality-adjusted life years have become the dominant outcome of interest in pharmacoeconomic evaluations, and many studies employ a cost-per-QALY analysis. Economic evaluations are carried out alongside randomized controlled trials and using methods of decision-analytic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Number Needed To Harm
In medicine, the number needed to harm (NNH) is an epidemiology, epidemiological measure that indicates how many persons on average need to be exposed to a risk-factor, risk factor over a specific period to cause harm in an average of one person who would not otherwise have been harmed. It is defined as the inverse of the absolute risk increase, and computed as 1/(I_e - I_u), where I_e is the Incidence_(epidemiology) , incidence in the treated (exposed) group, and I_u is the incidence in the control (unexposed) group. Intuitively, the lower the number needed to harm, the worse the risk factor, with 1 meaning that every exposed person is harmed. NNH is similar to number needed to treat (NNT), where NNT usually refers to a positive therapeutic result and NNH to a detrimental effect or risk factor. Marginal metrics: * NNT for an additional beneficial outcome (NNTB) * NNT for an additional harmful outcome (NNTH) are also used. __TOC__ Relevance The NNH is an important measure ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Number Needed To Vaccinate
Number needed to vaccinate (NNV) is a metric used in the evaluation of vaccines, and in the determination of vaccination policy. It is defined as the average number of patients that must be vaccinated to prevent one case of disease. It is a specific application of the number needed to treat metric (NNT). Derivation NNV is the inverse of the absolute risk reduction of the vaccine. If the incidence in the vaccinated population is I_e, and the incidence in the unvaccinated population is I_u, then the NNV is 1/(I_u - I_e). For example, one study reported a number needed to vaccinate of 5206 for invasive pneumococcal disease. Significance In order to determine a NNV, it is necessary to identify a specific population and a defined endpoint, because these can vary: * Tuberculosis vaccination rates are much higher in Europe than in the United States. * When evaluating a vaccine against chickenpox, it is necessary to define whether or not the endpoint would include shingles due to reacti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Population Impact Measures
Population impact measures (PIMs) are biostatistical measures of risk and benefit used in epidemiological and public health research. They are used to describe the impact of health risks and benefits in a population, to inform health policy. Frequently used measures of risk and benefit identified by Jerkel, Katz and Elmore, describe measures of risk difference (attributable risk), rate difference (often expressed as the odds ratio or relative risk), population attributable risk (PAR), and the relative risk reduction, which can be recalculated into a measure of ''absolute benefit'', called the number needed to treat. Population impact measures are an extension of these statistics, as they are measures of absolute risk at the population level, which are calculations of number of people in the population who are at risk to be harmed, or who will benefit from public health interventions. They are measures of absolute risk and benefit, producing numbers of people who will benefit fr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Business Week
''Bloomberg Businessweek'', previously known as ''BusinessWeek'' (and before that ''Business Week'' and ''The Business Week''), is an American monthly business magazine published 12 times a year. The magazine debuted in New York City in September 1929. Since 2009, the magazine has been owned by Bloomberg L.P. and became a monthly in June 2024. History 1929–2008: ''Businessweek'' ''The Business Week'' was first published based in New York City in September 1929, weeks before the stock market crash. The magazine provided information and opinions on what was happening in the business world at the time. Early sections of the magazine included marketing, labor, finance, management and Washington Outlook, which made it one of the first publications to cover national political issues that directly impacted the business world. The name of the magazine was shortened to ''Business Week'' in 1934. Originally published as a resource for business managers, the magazine shifted its s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Relative Risk
The relative risk (RR) or risk ratio is the ratio of the probability of an outcome in an exposed group to the probability of an outcome in an unexposed group. Together with risk difference and odds ratio, relative risk measures the association between the exposure and the outcome. Statistical use and meaning Relative risk is used in the statistical analysis of the data of Ecological study, ecological, Cohort study, cohort, medical and intervention studies, to estimate the strength of the association between exposures (treatments or risk factors) and outcomes. Mathematically, it is the incidence rate of the outcome in the exposed group, I_e, divided by the rate of the unexposed group, I_u. As such, it is used to compare the risk of an adverse outcome when receiving a medical treatment versus no treatment (or placebo), or for environmental risk factors. For example, in a study examining the effect of the drug apixaban on the occurrence of thromboembolism, 8.8% of placebo-treated pat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Primary Prevention
Preventive healthcare, or prophylaxis, is the application of healthcare measures to prevent diseases.Hugh R. Leavell and E. Gurney Clark as "the science and art of preventing disease, prolonging life, and promoting physical and mental health and efficiency. Leavell, H. R., & Clark, E. G. (1979). Preventive Medicine for the Doctor in his Community (3rd ed.). Huntington, NY: Robert E. Krieger Publishing Company. Disease and disability are affected by environmental factors, genetic predisposition, disease agents, and lifestyle choices, and are dynamic processes that begin before individuals realize they are affected. Disease prevention relies on anticipatory actions that can be categorized as primal, primary, secondary, and tertiary prevention. Each year, millions of people die of preventable causes. A 2004 study showed that about half of all deaths in the United States in 2000 were due to preventable behaviors and exposures. Leading causes included cardiovascular disease, chron ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hypertension
Hypertension, also known as high blood pressure, is a Chronic condition, long-term Disease, medical condition in which the blood pressure in the artery, arteries is persistently elevated. High blood pressure usually does not cause symptoms itself. It is, however, a major risk factor for stroke, coronary artery disease, heart failure, atrial fibrillation, peripheral arterial disease, vision loss, chronic kidney disease, and dementia. Hypertension is a major cause of premature death worldwide. High blood pressure is classified as essential hypertension, primary (essential) hypertension or secondary hypertension. About 90–95% of cases are primary, defined as high blood pressure due to non-specific lifestyle and Genetics, genetic factors. Lifestyle factors that increase the risk include excess salt in the diet, overweight, excess body weight, smoking, physical inactivity and Alcohol (drug), alcohol use. The remaining 5–10% of cases are categorized as secondary hypertension, d ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Atorvastatin
Atorvastatin, sold under the brand name Lipitor among others, is a statin medication used to prevent cardiovascular disease in those at high risk and to treat abnormal lipid levels. For the prevention of cardiovascular disease, statins are a first-line treatment in reducing cholesterol. It is taken by mouth. Common side effects may include diarrhea, heartburn, nausea, muscle pain (typically mild and dose-dependent) and, less frequently, joint pain. Muscle symptoms often occur during the first year and are commonly influenced by pre-existing health issues and the nocebo effect. Most patients can continue therapy with dose adjustment or statin switching. Rare (<0.1%) but serious side effects may include rhabdomyolysis (severe muscle disorder), liver problems and diabetes. Use during may harm the |
