| regression | 1. A return to a former or earlier state. 2. A subsidence of symptoms or of a disease process. 3. <psychiatry> A return to earlier, especially to infantile, patterns of thought or behaviour, a characteristic of many mental disorders also exhibited by normal persons in many situations, for example feelings of helplessness and dependency in a patient with a serious physical illness. Origin: L. Regressio = a return (18 Nov 1997) |
|---|---|
| regression analysis | Procedures for finding the mathematical function which best describes the relationship between a dependent variable and one or more independent variables. In linear regression (see linear models) the relationship is constrained to be a straight line and least-squares analysis is used to determine the best fit. In logistic regression (see logistic models) the dependent variable is qualitative rather than continuously variable and likelihood functions are used to find the best relationship. In multiple regression the dependent variable is considered to depend on more than a single independent variable. (12 Dec 1998) |
| regression of the mean | If, for a symmetrical population with a single mode, a measurement, selected because it is extreme, is repeated, on average the second reading will be closer to the mean than the first. (05 Mar 2000) |
| phonaemic regression | A decrease in intelligibility of speech associated with an increase in loudness. (05 Mar 2000) |
|---|---|
| mullerian regression factor | Mullerian duct inhibitory factor, a non-steroidal substance of foetal testicular origin that acts unilaterally to inhibit development of the paramesonephric (mullerian) ducts and acts with testosterone to promote development of the vas deferens and related structures. (05 Mar 2000) |
| corpus luteum regression | Involution and cessation of endocrine function of a corpus luteum. (12 Dec 1998) |
| neoplasm regression, spontaneous | Disappearance of a neoplasm or neoplastic state without the intervention of therapy. (12 Dec 1998) |
| law of regression to mean | In a population mating at random, the progeny of a parent with an extreme value for a measurable phenotype will tend on average to have values nearer the population mean than in the extreme parent. See: law of regression to mean. Synonym: law of regression to mean. (05 Mar 2000) |