Term
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Definition
| total number of cases of disease in a population |
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Term
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Definition
risk of developing a condition during an interval of time, written as a percentage
= # of new cases during an interval/
population at risk |
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Term
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Definition
| Person-time incidence rate = # of new cases during an interval/ people-years at risk |
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Term
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Definition
| the sum of the time periods of observation for all individuals in the population at risk during the study time frame |
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Term
| Experimental Event Rate (EER) |
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Definition
| a measure of how often a particular statistical event occurs within the experimental group of an experiment |
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Term
| Cumulative Incidence Exposed |
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Definition
| risk that someone exposed will develop the condition |
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Term
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Definition
| a measure of how often a particular statistical event occurs within the control group of an experiment |
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Term
| Cumulative Incidence Un-exposed |
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Definition
| risk that someone not exposed will develop the condition |
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Term
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Definition
risk that someone who was exposed will develop a condition, relative to those unexposed
RR = EER/CER |
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Term
| Relative Risk Reduction (RRR) |
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Definition
amount of risk that has been REDUCED in getting a disease by not being exposed, relative to being exposed to some variable
RRR = (CER-EER)/CER |
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Term
| Absolute Risk Reduction (ARR) |
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Definition
Difference in risk (amount reduced) in getting a disease between the non-exposed and exposed groups
ARR = CER - EER |
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Term
| Number Needed to Treat (NNT) |
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Definition
| NNT = 1/ARR How many people would you have to give treatment or the intervention to before you seee improvement in one person The lower the NNT the better the treatment must be |
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Term
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Definition
odds of event occurring in one group relative to odds of it occurring in another group
-used for case control studies |
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