Term
| Epidemiology is founded on what 2 functions? |
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Definition
1. Human disease does not occur at random
2. Human disease has causal and preventative factors that are identifiable |
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Term
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Definition
| The study of the distribution of determinants of disease frequency in human populations |
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Term
| 2 Ways to study the frequency of an existing disease |
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Definition
Prevalent Cases - number of persons who have a disease at a point in time
Prevalence - Proportion of population with a disease at a certain time. |
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Term
| Ways to measure frequency of diseases over time |
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Definition
Incident disease events - incidences of a disease during a period
Incident cases - persons who develop a disease during a period
Cumulative Incidence – proportion of new cases in a population during a specific time (a proportion)
Incidence Rate – number of cases per person-time at risk (a rate) |
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Term
| Special types of incidence |
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Definition
Mortality - deaths in a population per total population over a certain time
Case fatality – proportion of persons with a disease who die to the total persons with that disease
Proportionate Mortality – Proportion of deaths due to a particular disease to total deaths |
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Term
| 3 Ways to study cases epidemiologically |
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Definition
Case study – study people already with disease and look at factors
Cohort study – study people without a disease and tract incidence
Randomized Control Trial – study effect of treatments versus the effects of no treatment via double blind studies |
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Term
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Definition
| Clinical Epidemiology – The study of variation in the outcome of disease and of the reasons for that variation |
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Term
| Differences between Epidemiology and Clinical Epidemiology? |
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Definition
| The difference is study of occurrence (epidemiology) vs. outcome (Clinical ep.)) |
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Term
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Definition
| Statistic dependence between two variables |
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Term
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Definition
| An act or event which initiates or permits (possible with other causes) a sequence of events that leads to an effect |
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Term
| Possible explanations of associations besides cause |
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Definition
| Chance, Bias, Confounding, True Association |
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Term
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Definition
| "p-value" - the probability that something could have occurred by chance |
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Term
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Definition
| A systematic error in the way individuals are selected or the way observations are collected or evaluated. |
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Term
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Definition
Selection Bias - groups of exposed or unexposed subjects differ in a way that effects outcome
Recall Bias - differential recall of events
Performance Bias - difference in provision of care or application of the intervention |
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Term
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Definition
| Presence of an additional factor that effects the outcome and is not accounted for |
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Term
| Criteria to Judge the presence of a cause-effect relationship |
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Definition
Strength of Association
Consistency of the Association
Temporal Relationship
Dose-Dependent Gradient
Biologic Plausibility |
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Term
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Definition
| Stronger the association the less likely likely there is a confounding variable (NOT P VALUE!) |
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Term
| Consistency of Association |
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Definition
| Repetitive Demonstration by different studies to show the association |
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Term
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Definition
| The cause should come before the effect |
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Term
| Dose-Response Relationship |
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Definition
An increase in decrease in exposure should lead to a corresponding change in the associated outcome
this doesn't prove causation |
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Term
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Definition
| A known or postulated biological mechanism that explains how the exposure might reasonably alter the risk of an outcome |
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Term
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Definition
| The whole collection of units from which a sample may be drawn |
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Definition
| A selected subset of a population |
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Term
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Definition
| the extent to which the same result can be obtained with repeated measures |
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Definition
| the degree to which a variable actually represents what it is supposed to represent |
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Term
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Definition
| A sample chosen because the subjects are easily available but not ideal, may not accurately represent the population |
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Term
| Descriptive Studies + Examples |
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Definition
Designed only to describe the distribution of variable, hypothesis generating
i.e. case report, cross sectional, and case series |
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Term
| Analytic Studies + Example |
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Definition
Designed to examine associations or hypothesis, have a control group and often measure risk factors or health effects of exposures
i.e. Observational (Case-control and cohort) and experimental (randomized control trial) |
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Term
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Definition
| The proportion of a population with a disease at a specific time. This represents the chance that a person at random has a disease |
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Term
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Definition
| A measure of New cases of disease which occur in a population at risk during a specified period of observation |
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Term
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Definition
| The proportion of the population who experience an event during a stated time, describes risk (New cases of disease during observation/ population at risk at start of observation) |
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Term
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Definition
The rate at which new cases develop in a population relative to the size of the population, the average rate (New cases of Disease / Time at risk in a population)
-presented in person-years |
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Term
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Definition
| Incidence: Total Deaths / Total Population |
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Term
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Definition
| Incidence: deaths due to a particular disease / number of persons with disease |
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Term
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Definition
| incidence: deaths due to a particular disease / total number of deaths |
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Term
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Definition
| compares the difference in average values between sample |
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Term
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Definition
| Test that unequivocally detects presence of a condition or disease (biopsy, cardiac catheterization etc.) |
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Term
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Definition
| A disease is present and the test says it is present |
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Term
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Definition
| Disease is absent and test indicates the disease is absent |
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Term
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Definition
| Test indicates disease is present but in actuality the disease is absent |
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Term
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Definition
| Test indicates that a disease is absent but in actuality the disease is present |
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Term
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Definition
The true positive rate, the proportion of patients with the disorder who received a positive test result
TP / (FN + TP) |
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Term
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Definition
True negative rate, the proportion of patients without the disorder who receive a negative result
TN / (FP + TN) |
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Term
| Positive Predictive Value |
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Definition
proportion of patients with a positive test who have the disorder
TP / (TP + FP) |
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Term
| Negative Predictive Value |
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Definition
proportion of patients with a negative test who are free of the disorder
TN / (TN + FN) |
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Term
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Definition
Studies people already with a disease and look for factors
Looks at an outcome or don't have an outcome and look at which exposures were present.
Measures an outcome
Exposure is NOT assigned |
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Term
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Definition
Study people without a disease and track incidence
Present at beginning of study with some exposed and some not exposed
BASED ON THE EXPOSURE
HAS A CONTROL GROUP |
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Term
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Definition
Study effect of treatments versus the effects of no treatment in double blind studies
Patients are exposed or not exposed then measured for outcomes |
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Term
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Definition
| indicates the probability that something occurs at random |
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Term
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Definition
Measurement without a control group, where present at beginning of study and measure outcomes later
on an individual |
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Term
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Definition
| Relationship between an exposure and an outcome where both are measured at the same time |
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Term
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Definition
| The alternative hypothesis that on seeks to deny in order to accept the alternative hypothesis |
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Term
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Definition
| An opposing hypothesis that cannot be rejected and is thus accepted upon rejection of the null hypothesis |
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Term
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Definition
| If SPecificity is high, then positive test rules-IN the diagnosis |
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Term
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Definition
| If sensitivity is high, then negative test rules-OUT the diagnosis |
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Term
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Definition
Lead time bias - the error that reduced mortality is resulting from earlier detection not more effective treatment
length bias - the error that reduced mortality because of screening causes by disproportionate detection of less aggressive disease. |
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Term
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Definition
Odds of the disease given exposure divide by odds of the disease with no exposure
this gives overall odds that a disease is caused by an exposure |
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Term
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Definition
| A false positive... when you reject the null hypothesis but it is actually true |
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Term
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Definition
| False Negative - Fail to reject the null hypothesis when the null hypothesis is false |
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Term
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Definition
| All subject need to be accounted for at the end of the study |
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Term
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Definition
| Subjects are all treated equally, no matter which group they are a part of |
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Term
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Definition
| labels, names that have no implied order or magnitude |
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Term
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Definition
| Categories that have logical order and magnitude but have a separation between levels |
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Definition
| numbers or numerical levels with implied order and magnitude and constant distance between levels |
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Term
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Definition
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Term
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Definition
| Non-continuous data points |
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Term
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Definition
| The study is mechanically sound and is accurate without bias, confounding and chance has been ruled out |
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Term
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Definition
| The results of a study can be generalized outside the sample set. |
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Term
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Definition
| the thickness of the tails, or the variance of values at both extremes which affects the ‘peakedness’ or height of the center of the distribution |
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Term
| Survey Research is often used in what type of study? |
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Definition
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