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15 Cards in this Set
- Front
- Back
Disease, illness and ill health are not ____ distributed in a population.
Disease is the product of an interaction between a _____ human host, an infectious or other type of _____ and the environment that promotes the exposure. *A vector may be involved. Human susceptibility is determined by a variety of factors including ____ background and nutritional and _____ characteristics. |
randomly
susceptible; agent genetic; immunologic |
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The potential of a given organism for spreading and producing outbreaks depends on specific characteristics of the organism such as the rate of ____ and the ____ by which it is transmitted from one person to another.
Different portals of entry include: alimentary tract, urogenital systems, and the skin. The objectives of epidemiology are to identify ____/ causes of disease and risk factors; to determine the ___ of disease in communities; to ____ preventative and therapeutic measures and health delivery systems; and to provide the foundation for _____ making and regulatory decision making. |
growth
route etiology extent evaluate policy |
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Occurrence of disease can be measured using ____, which tell us how fast the disease is occurring in a population and ____ which tell us what fraction of the population is affected.
Because the incidence rate is a measure of the transition from a _____ state to a diseased state, the incidence is a measure of _____. The denominator of an incidence rate represents the number of people who are at ____ for developing the disease. Any individual in the denominator must have the _____ to become part of the group that is counted in he numerator. |
rates; proportion
non-diseased; risk risk; potential |
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When different individuals are observed for different lengths of time we calculate an incidence rate in which the denominator consists of the ____ of units of time that each individual was at risk and was observed. This is called ____-time and is often expressed in terms of person-months/years of observation.
The incidence rate calculated using a period of time during which all of the individuals in the population are considered to be at risk for the outcome is called ______ incidence. Ex: Have you ever had asthma? The number of individuals who move from the disease free state to the disease state during any period of time is the product of three factors: [1] the ___ of the population, [2] the length of the time period, and [3] the force of ____. |
sum; person
cumulative size; morbidity |
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When calculating incidence, if the population is much larger than the number of existing cases, then the number of existing cases may be ____ from the denominator.
Ex: Pop = 80, 000; new cases = 20; existing cases = 60. Incidence = 20/20,000. If the denominator is not much larger than the number of existing cases than the number of existing cases must be _____ in the denominator. *Incidence is always Per 100, 000!* Ex: pop = 80,000; new cases = 200; existing cases = 7000. Incidence = 200/ (80, 000-7000) |
excluded
included |
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The prevalence rate is the number of cases of disease ____ in the population at a specified time divided by the number of persons in the population at _____ at that specified time. Prevalence is more of a _____ than a rate and does not measure ____.
Prevalence provides a ____ of the population at a certain point in time illustrating who has the disease and who does not. This is referred to as ____- prevalence. Ex: "Do you currently have asthma?" Period prevalence measures the amount of people who have had a disease ____ a certain period. Ex: during one calendar year. "Have you had asthma during the last year?" |
present; risk
proportion; risk snapshot; point during |
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A person-year is a unit combining time and ____ size.
Person year = number of persons x observed years ex: 1000 persons observed for 20 years = 20, 000 person-years. Prevalence is used to measure/estimate the ____ of disease in a community and is very useful for planning health services. Prevalence = incidence x Duration of disease |
population
burden |
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Surveillance is carried out to monitor changes in disease ____ or to monitor changes in ____ of risk factors.
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frequency; prevalence
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Mortality rates can serve as measures of disease _____ and can help us to determine whether the treatment for a disease has become more _____ over time.
Mortality rates may serve as surrogates for ____ rates when the disease being studied is a severe and lethal one. For mortality rates, every person in the denominator must be at ____ for being in the numerator. When a restriction is placed on a rate it is called a ____. |
severity; effective
incidence risk specified |
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Case-fatality rates are percentages and explain what percentage of people diagnosed with a certain disease ___ within a certain time after diagnosis.
# of individuals dying during a specified period of time after disease onset or diagnosis/ # of individuals with the specified disease. Case-fatality is a measure of the ____ of the disease. Proportionate mortality is also a percentage and explains the proportion of deaths in the U.S caused by a ____. # of deaths from disease in the U.S in specific year/ all deaths in the U.S in specific year |
die
severity disease |
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YPLL is a statistical measure of ____ death and years of potential life lost compared to a target age (65). It is usually used for setting health priorities, establishing research, ____ of temporal trends in premature mortality, and evaluating the ______ of program interventions.
YPLL rate per 100,000 is used to compare among _____ places, races and countries. Standardized mortality ratio (SMR): Observed # of deaths per year/ expected # of deaths per year. An SMR of 100 indicates that the observed number of deaths is ____ to the expected number of deaths. An SMR greater than 100 indicates that the observed number of deaths ____ the expected number, and an SMR less than 100 indicates that the observed number of deaths is ____ than the expected. |
premature
surveillance; effectiveness different equal exceeds; less |
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A test's ability to distinguish between who has a disease and who does not is called a test's _____.
Validity has two components: sensitivity and specificity. The ability of the test to identify correctly those who have the disease is called the test's ______; and incorrectly is called the test's _____. Sensitivity = Positive and diseased/ Total diseased = TP/ TP + FN Specificity = Negative no disease/ Total non-diseased TN/ TN + FP |
validity
sensitivity specificity |
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If there is a low cut off, the ____ is increased and there is an increase in false positives therefore decreasing the ____ and false negatives.
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sensitivity; specificity
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The positive predictive value explains what _____ of patients who test positive actually have the disease.
PPV = TP/ Total Positive Negative predictive value explains what proportion of those who tested negative actually do not have the disease. NPV = TN/ Total Negative The predictive value is affected by the ____ of the disease in the proportion tested and when the disease is infrequent. An increase in specificity produces a larger increase in the _____ than sensitivity. |
proportion
prevalence PPV |
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A cohort is a group of people who share a common characteristic or _____ within a defined period. The comparison group may be the general population from which the cohort is drawn or it may be another cohort of persons thought to have little to no ____ to the substance under investigation, but otherwise similar.
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experience
exposure |