R

Select a term to view the definition:
  • radioallergosorbent test

    Professional Description:

    RAST is an abbreviation for RadioAllergoSorbent Test, a trademark of Pharmacia Diagnostics, which originated the test. RAST is a laboratory test used to detect IgE antibodies to specific allergens (2). CAP-RAST is a specific type of RAST. RAST is a allergy test carried out on a sample of blood. The aim with RAST, as with skin tests, is to check for allergic sensitivity to specific antigens. In the test, the sample of blood is mixed with substances known to trigger allergies. The test measures the level of IgE allergy antibodies to specific antigens in the blood which are present if there is a allergic reaction

  • Random Sample

    Professional Description:

    "A sample derived by selecting sampling units (for example, individual patients) such that each unit has an independent and fixed chance of selection. Whether a given unit is selected is determined by chance (for example, by a table of randomly ordered numbers)." Source: JAMA Instructions for authors. JAMA. 1996;275(1):8. Available from: https://jamanetwork.com/journals/jama/article-abstract/393429.

  • Ratings of perceived exertion

    Professional Description:

    A subjective rating using a numerical scale that expresses the perceived difficulty of a given exercise task.

  • Raw Food Diet

    Professional Description:

    A raw food diet is a diet of uncooked foods. Typically this is a vegan diet, although in a small proportion of cases animal products such as raw meat or fish are included.

  • RCT

    Professional Description:

    Randomized control trial

  • Reactive Species

    Professional Description:

    This is a general term used to describe substances that are highly reactive - i.e., they can react with and damage other molecules. The primary reactive species include reactive oxygen species (ROS) and reactive nitrogen species (RNS). These in turn react with other compounds in the body and generate radical intermediates of lipids, proteins, and nucleic acids that ultimately form the chemical end products of oxidative stress.

  • Recall Bias

    Professional Description:

    "Systematic error due to differences in accuracy or completeness of recall to memory of past events or experiences. For example, a mother whose child has died of leukemia may be more likely than the mother of a healthy living child to remember details of such past experiences as use of x-ray services when the child was in utero." Source: Porta M, ed. A Dictionary of epidemiology, 6th edition. New York: Oxford University Press; 2014.

  • Recannulation

    Professional Description:

    The resiting or siting a cannula; a cannula is a flexible tube that is inserted into the body to withdraw fluid or insert medication. A venous cannula is inserted into a vein, primarily for the administration of intravenous fluids and medicines.

  • Recommend Nutrient Intakes

    Professional Description:

    Recommend Nutrient Intakes

  • Recommended Dietary Allowance

    Professional Description:

    The average daily dietary intake level that is sufficient to meet the nutrient requirement of nearly all (97 to 98 percent) healthy individuals in a particular life stage and gender group.

  • Recommended Intake

    Professional Description:

    For an individual, the recommended intake is one that is almost certain to meet or exceed their individual requirement. The RDA and the AI are both recommended intakes for individuals.

  • Reference Body Weights

    Professional Description:

    Reference body weight is the weight for individuals at the median height, at a median BMI within an age range, calculated from national reference data.

  • Refractory HF

    Professional Description:

    The most advanced form of heart failure which occurs when a heart failure patient remains symptomatic despite optimal medical therapies.

  • Regulated discretionary fortification

    Professional Description:

    The optional addition of any nutrient from a defined list of vitamins and minerals, over defined ranges, at the discretion of food manufacturers.

  • Regurgitation

    Professional Description:

    Passage of refluxed gastric contents into the oral pharynx.

  • Reinforcement management

    Professional Description:

    A technique in which a person is rewarded for completing a specific behaviour.

  • Relative Risk

    Professional Description:

    "Ratio of the risk of an event among an exposed population to the risk among the unexposed." Source: JAMA evidence. American Medical Association; 2014 Jun. Available from: http://www.jamaevidence.com/glossary.

  • Relative Risk Reduction

    Professional Description:

    "The proportional reduction in rates of harmful outcomes between experimental and control participants. It is calculated by dividing the rate of harmful outcome in the control group (CER) minus the rate of harmful outcome in the experimental group (EER) by the rate of harmful outcome in the control group [(CER–EER)/CER]. Used with a beneficial exposure or intervention." Source: JAMA evidence. American Medical Association; 2014 Jun. Available from: http://www.jamaevidence.com/glossary.

  • Release of inflammatory mediators from mast cells

    Professional Description:

    Inflammatory mediators such as histamine and degradative enzymes stored within the intracellular granules of mast cells are released into the surrounding tissues, resulting in symptoms of allergy after degranulation.

  • Reliability

    Professional Description:

    Reliability refers to the extent to which a measure or tool obtains similar results over repeated trials/ uses (i.e. the trustworthiness). There are several types of reliability: Test-retest Reliability - whether the self-administered measure obtains similar results when repeated by the same individuals over time. Inter-rater Reliability - whether the measure obtains similar results when rated or scored by different people. Intra-rater Reliability - whether the measure obtains similar results when rated or scored by the same person over time. Source: The Cochrane Collaboration. Glossary. [cited 2019 Nov 4 17]. Available from: https://community.cochrane.org/glossary Last JM. A dictionary of epidemiology. 4th Edition. New York: Oxford University Press; 2001.

  • Reliability Measures of Categorical Data

    Professional Description:

    "1. “inter-observer bias: reflected in differences in the marginal distributions of the response variable for each of the observers 2. observer disagreement: indicated by how observers classify individual subjects into the same category on the measurement scale. K Strength of agreement 0.01 Poor 0.00 - 0.20 Slight 0.21 – 0.40 Fair 0.41 – 0.60 Moderate 0.61 – 0.80 Substantial 0.81 – 1.00 Almost perfect" Source: Everitt BS. Statistical methods for medical investigations. 2nd ed. New York: Halsted Press; 1994.

  • Renal solute load

    Professional Description:

    Renal solute load (RSL) refers to all solutes of endogenous or dietary origin that require excretion by the kidneys

  • Research

    Professional Description:

    "A class of activities designed to develop or contribute to generalizable knowledge, consisting of theories, principles, or relationships, or accumulation of information on which these are based, that can be corroborated by acceptable scientific methods of observation, inference, and/or experiment." Source: Porta M, ed. A Dictionary of epidemiology, 6th edition. New York: Oxford University Press; 2014.

  • Residual confounding

    Professional Description:

    the effect that remains after one has attempted to statistically control variables that cannot be measured perfectly. These unknown variables could obscure or exaggerate existing associations, and could significantly change conclusions made on the basis of epidemiological research

  • Resistance exercise

    Professional Description:

    Consists of activities that use muscular strength to move a weight or work against a resistant load. Examples include weight lifting and exercises using weight machines.

  • Response bias

    Professional Description:

    Factors or conditions that take place during the process of responding to surveys that affect the way responses are provided, leading to a nonrandom deviation of answers from their true value.

  • Resting energy expenditure

    Professional Description:

    Resting metabolic rate extrapolated to 24 hours to be more meaningful. (see resting metabolic rate).

  • Resting metabolic rate

    Professional Description:

    Energy expenditure under resting conditions.

  • Retinol

    Professional Description:

    Retinol, the dietary form of vitamin A, is a fat-soluble, antioxidant vitamin important in vision and bone growth. It belongs to the family of chemical compounds known as retinoids. Retinol is ingested in a precursor form; animal sources (milk and eggs) contain retinyl esters, whereas plants (carrots, spinach) contain carotenoids. Tissue cells convert these precursors to retinol, and then to either retinal or retinoic acid.

  • Retinol Activity Equivalent

    Professional Description:

    The Recommended Dietary Allowances (RDA) for vitamin A are listed as Retinol Activity Equivalents (RAE) to account for the different activities of retinol and provitamin A carotenoids. Sometimes RDAs are also listed in International Units (IU) because food and some supplement labels list vitamin A content in International Units (1 RAE in micrograms = 3.3 IU).

  • Review Paper

    Professional Description:

    "A summary of the literature on a topic; tend to be descriptive. The identification of studies and their interpretation is determined by the author(s) and may be biased." Source: Porta M, ed. A Dictionary of epidemiology, 6th edition. New York: Oxford University Press; 2014.

  • Rhinoconjunctivitis

    Professional Description:

    An immunologically-mediated hypersensitivity reaction in the nose and conjunctiva. Most cases are IgE-mediated.

  • Rhinorrhea

    Professional Description:

    Runny nose with watery discharge characteristic of the common cold.

  • Rhodes Index

    Professional Description:

    a self-report form that has eight questions, each answered with a five-point Likert-type scale that measures the patient’s perceived duration, frequency and distress from nausea, vomiting and retching

  • Rickets

    Professional Description:

    Rickets is a childhood disease where growing bone matrix fails to mineralize, which can lead to skeletal deformities, bone pain and delayed motor development.

  • Risk Assessment

    Professional Description:

    An organized framework for evaluating scientific information, which has as its objective a characterization of the nature and likelihood of harm resulting from excess human exposure to an environmental agent (in this case, a dietary nutrient). It includes the development of both qualitative and quantitative expressions of risk. The process of risk assessment can be divided into four major steps; hazard identification, dose-response assessment, exposure assessment, and risk characterization.

  • Risk Characterization

    Professional Description:

    The final step in a risk assessment, which summarizes the conclusions from Steps 1 through 3 of the risk assessment and evaluates the risk. This step also includes a characterization of the degree of scientific confidence that can be placed in the UL.

  • Risk Management

    Professional Description:

    The process by which risk assessment results are integrated with other information to make decisions about the need for, method of, and extent of risk reduction. In addition to risk assessment results, risk management considers such issues as the public health significance of the risk, the technical feasibility of achieving various degrees of risk control, and the economic and social cost of this control.

  • Rosacea

    Professional Description:

    A chronic inflammatory disorder consisting of vascular and follicular dilation primarily of the skin of the nose, forehead and cheeks. It is characterized by erythema (redness due to capillary dilation), hyperplasia of sebaceous glands, papules and pustules, and telangiectasia (dilation of the vessels).

  • Roux-en-Y gastric bypass

    Professional Description:

    The most common form of gastric by-pass surgery is a Roux-en-Y gastric bypass. In this procedure the stomach is made smaller by creating a small pouch at the top of the stomach with surgical staples or a plastic band. The smaller stomach is connected directly to the middle portion of the small intestine (jejunum), bypassing the rest of the stomach and the upper portion of the small intestine (duodenum).

  • Run-in Period

    Professional Description:

    "A period before a trial is commenced when no treatment is given. The data from this stage of a trial are only occasionally of value but can serve a valuable role in screening out ineligible or non-compliant participants, in ensuring that participants are in a stable condition, and in providing baseline observations. A run-in period is sometimes called a washout period if treatments that participants were using before entering the trial are discontinued." Source: The Cochrane Collaboration. Glossary. [cited 2019 Aug 17]. Available from: https://community.cochrane.org/glossary.