- rate
**1.**A*record*of the*measurement*of an*event*or*process*in terms of its*relation*to some fixed*standard*;*measurement*is expressed as the*ratio*of one quantity to another ( e.g.,*velocity*,*distance*per*unit*time).**2.**A*measure*of the*frequency*of an*event*in a defined*population*; the components of a r. are: the numerator (*number*of events); the*denominator*(*population*at*risk*of experiencing the event); and the specified*time*in which the events occur. [L. ratum, a reckoning (see ratio)]-*abortion*r.**1.**the*number*of induced abortions per 1000 preganancies that resulted in a*livebirth*,*stillbirth*, or induced*termination*.**2.**the*number*of terminations ×1000 ÷ the*female**population*ages 15–44 years.-**age-**a r. for a specified age*specific*r.*group*, in which the numerator and*denominator*refer to the same age*group*.-a*attack*r.*cumulative**incidence*r. used for particular groups observed for limited periods under special circumstances, such as during an*epidemic*.-the*average**flow*r.*flow*r. determined by dividing the total*volume*of*urine*passed by the*time*of voiding.-**baseline**the*fetal**heart*r.*average**heart*r. for a particular*fetus*during the*diastolic**phase*of*uterine*contractions.-a summary r. based on the*birth*r.*number*of live births in a*population*over a given*period*, usually 1*year*; the numerator is the*number*of live births, the*denominator*is the midyear*population*.-the proportion of a*concordance*r.*random**sample*of pairs that are*concordant*for a*trait*of interest. A high r. of*concordance*may be generated in several ways, many of which may result from irrelevant*bias*; but broadly it is taken as evidence of causal*connection*( e.g., in the*case*of identical twins, a*genetic**component*or in spouses of assortative mating).-a*critical*r.*heart*r. at which*aberration*or incomplete*block*will occur; a result of shortening of*cycle**length*so that it barely includes the*refractory**period*.-an*death*r.*estimate*of the proportion of the*population*that dies during a specified*period*, usually a*year*; the numerator is the*number*of people dying, the*denominator*is the*number*in the*population*, usually an*estimate*of the*number*at the midperiod. SYN: crude death r.,*lethality*r.,*mortality*r.,*mortality*(2).-(ESR) the r. of settling of red*erythrocyte**sedimentation*r.*blood*cells in anticoagulated*blood*; increased rates are often associated with*anemia*or*inflammatory*states.-the*fatality*r.*death*r. observed in a designated*series*of persons affected by a simultaneous*event*such as a disaster.-the*fetal**death*r.*number*of*fetal*deaths divided by the sum of live births and*fetal*deaths occurring in the same*population*during the same*time**period*. SYN:*stillbirth*r..-**five-year**the proportion of patients still alive five years after a*survival*r.*diagnosis*or*form*of*treatment*is completed. Usually applied to*statistics*of*survival*of*cancer*patients, since, after five years, recurrences are much less likely to occur.-**general**a refined*fertility*r.*measure*of*fertility*in a*population*; the numerator is the*number*of live births in a*year*, the*denominator*is the*number*of females of child-bearing age, usually defined as ages 15–44 (but increasingly recognized as extending to age 49).-(GFR) the*glomerular**filtration*r.*volume*of*water*filtered out of the*plasma*through*glomerular**capillary*walls into*Bowman*capsules per*unit**time*; it is considered to be*equivalent*to*inulin**clearance*.-the*gross**reproduction*r.*average**number*of*female*children a woman would have if she survived to the end of her*childbearing*years and if, throughout that*period*, she were*subject*to a given set of age-specific*fertility*rates and a given sex*ratio*at*birth*; this r. provides a*measure*of the*replacement**fertility*of a*population*in the*absence*of*mortality*.-a*growth*r. of*population**measure*of*population**change*in the*absence*of*migration*, comprising addition of newborns and*subtraction*of deaths; the result is known as the natural r. of*increase*of the*population*; it is the*difference*between the crude*birth*r. and the crude*death*r..-**hazard r.**theoretical*measure*of the*risk*of occurrence of an*event*, e.g.,*death*, new*disease*, at a*point*in*time*.-the r. at which new events occur in a*incidence*r.*population*. The numerator is the*number*of new events occurring in a defined*period*; the*denominator*is the*population*at*risk*of experiencing the*event*during this*period*.-a*infant**mortality*r.*measure*of the r. of deaths of liveborn infants before their first birthday; the numerator is the*number*of infants under one*year*of age born alive in a defined*region*during a calendar*year*who die before they are one*year*old; the*denominator*is the total*number*of live births; often quoted as a useful*indicator*of the*level*of*health*in a*community*.-**initial r.**SYN: initial velocity.-the*maternal**death*r.*number*of*maternal*deaths that occur as the direct result of the*reproductive**process*per 100,000 live births. See r.. SEE ALSO:*maternal*death. SYN:*maternal**mortality*ratio.-the proportion of cells in a*mitotic*r.*tissue*that are undergoing*mitosis*, expressed as a*mitotic**index*or, roughly, as the*number*of cells in*mitosis*in each*microscopic*high-power*field*in*tissue*sections.-the proportion of patients with a particular*morbidity*r.*disease*during a given*year*per given*unit*of*population*.-*mucociliary**clearance*r.*velocity*of*movement*of the*mucus**blanket*over*respiratory**epithelium*, usually expressed in mm/hour.-the*mutation*r.*probability*(or proportion) of*progeny*genes with a particular*component*of the*genome*not*present*in either*biologic**parent*; usually expressed as the*number*of mutants per*generation*occurring at one*gene*or*locus*.-the*neonatal**mortality*r.*number*of deaths in the first 28 days of*life*divided by the*number*of live births occurring in the same*population*during the same*period*of*time*.-the*perinatal**mortality*r.*number*of*stillborn*infants of 24 completed weeks or more plus the*number*of deaths occurring under 28 days of*life*divided by the*number*of*stillborn*infants of 24 weeks or more*gestation*plus all liveborn infants in the same*population*, regardless of the*period*of*gestation*.-in*recurrence*r.*genetic**counseling*, the*risk*that a future offspring will be affected given some*specific*set of relatives of whom at least one is already affected.-**repetition r.**the*number*of pulses per minute, describing an*energy**output*, e.g.,*ultrasound*pulses in*echocardiography*rather than*vascular*pulses.-the r. at which a*sedimentation*r.*sediment*is deposited from a*solution*. SEE ALSO:*erythrocyte**sedimentation*r..-the*shear*r.*change*in*velocity*of parallel planes in a flowing*fluid*separated by*unit**distance*; its units expressed in seconds^{−1}.-**slew r.**in*electronic**pacemaker**function*, the*maximum*r. of*change*of an*amplifier**output**voltage*; important*variable*affecting*heart**function*as controlled by an*electronic**pacemaker*.*Sensing*circuits in the*pacemaker*often respond to the slew r. rather than to the*absolute**amplitude*of the*voltage**pulse*.-**steady-state r.**SYN: steady-state velocity.-(MCR) a*steroid**metabolic**clearance*r.*measure*of the r. of*metabolism*of a given*steroid*within the*body*, usually expressed as liters of*body**fluid*that contain the amount of*steroid*metabolized per day.-the total quantity of a given*steroid*production r.*steroid*formed in the*body*, usually expressed as milligrams per day; represents the sum of the*glandular**secretion*of the*steroid*and extraglandular*formation*of it from various*steroid*precursors.-the r. of*steroid**secretory*r.*glandular**secretion*of a given*steroid*, usually expressed as milligrams per day; does not include any amount of the*steroid*that might be formed extraglandularly.-**voiding***flow*r.*urinary**flow*as a*function*of*time*during*micturition*, as graphically recorded by a*flow**meter*.* * *

**rate 'rāt***n***1)**a fixed ratio between two things**2)**a quantity, amount, or degree of something measured per unit of something else*see***DEATH RATE***,***HEART RATE***,***METABOLIC RATE***,***PULSE RATE***,***SEDIMENTATION RATE*** * *

(rāt) [L.*rata,*from*rates*calculated] 1. the amount of change of a physical quantity or number of occurrences of an event per unit time. 2. in epidemiology and demography, the frequency of an event in a specified population; correctly applied only to fractions for which all of the cases contributing to the numerator are also counted in the denominator and for which the denominator is the entire population at risk. Rates are often multiplied by a factor to give the number of events per 1000, 10,000, or 100,000 population. 3. more generally, a term sometimes used to denote some measured quantity with respect to another. Symbol R.

*Medical dictionary.
2011.*