| predictive validity | Criterion-related validity used to predict performance in a real-life task at a future time. See: construct validity, criterion-related validity. (05 Mar 2000) |
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| predictive value | An expresion of the likelihood that a given test result correlates with the presence or absence of disease. A positive predictive value is the ratio of patients with the disease who test positive to the entire population of individuals with a positive test result; a negative predictive value is the ratio of patients without the disease who test negative to the entire population of individuals with a negative test. (05 Mar 2000) |
| predictive value of tests | In screening and diagnostic tests, the probability that a person with a positive test is a true positive (i.e., has the disease), is referred to as the predictive value of a positive test; whereas, the predictive value of a negative test is the probability that the person with a negative test does not have the disease. Predictive value is related to the sensitivity and specificity of the test. (12 Dec 1998) |
| accumulation analysis | A technique in which an intermediate of a metabolic pathway accumulates due to selective inhibition of a particular step in that pathway or in a mutant that is deficient in a certain step. The intermediate is then isolated, analyzed, and identified. (05 Mar 2000) |
| activation analysis | <radiobiology> Method for identifying and measuring chemical elements in a sample of material. Sample is first made radioactive by bombardment with neutrons, charged particles, or gamma rays. Newly formed radioactive atoms in the sample then give off characteristic radiations (such as gamma rays) that tell what kinds of atoms are present, and how many. (09 Oct 1997) |
| actuarial analysis | The application of probability and statistical methods to calculate the risk of occurrence of any event, such as onset of illness, recurrent disease, hospitalization, disability, or death. It may include calculation of the anticipated money costs of such events and of the premiums necessary to provide for payment of such costs. (12 Dec 1998) |
| amino acid analysis | Determination and identification of amino acid content of a macromolecule, identification of a specific amino acid in macromolecules, often a mutated protein, identification and quantitation of amino acid content in blood plasma or urine; a key diagnostic aid. (05 Mar 2000) |
| analysis | <technique> The separation into component parts or elements, the act of determining the component parts of a substance. Origin: Gr. Lysis = dissolution (18 Nov 1997) |
| analysis of variance | A statistical technique that isolates and assesses the contributions of categorical independent variables to variation in the mean of a continuous dependent variable. (12 Dec 1998) |
| base sequence analysis | <molecular biology> A method, sometimes automated, for determining the base sequence. (09 Oct 1997) |
| bite analysis | A study of the relations of the occlusal surfaces of opposing teeth and their effect upon related structures. Synonym: bite analysis. (05 Mar 2000) |
| blood gas analysis | <investigation> A test which analyses arterial blood for oxygen, carbon dioxide and bicarbonate content in addition to blood pH. Used to test the effectiveness of respiration. (27 Sep 1997) |
| bradykinetic analysis | The analysis of a movement by means of slow cinematography. (05 Mar 2000) |
| breath analysis test | A test of hepatic and intestinal absorptive function; aminopyrine labelled with radioactive carbon is administered orally; expired 14CO2 is a measure of aminopyrine absorption and its metabolism in the liver; a measurement of the amount of 14CO2 exhaled after an oral dose of 14C-O-xylose; a measurement of exhaled hydrogen gas following an oral dose of lactose as a test of lactose deficiency. (05 Mar 2000) |
| gastric analysis | Measurement of pH and acid output of stomach contents; basal acid output can be determined by collecting the overnight gastric secretion or by a 1-hr collection; maximal acid output is determined following injection of histamine; output is measured by titration with a strong base. (05 Mar 2000) |