Epidemiology Lesson 3
The relative magnitude of two quantities or a comparison of any two values.
Can be written as the value:1 ex. 12.6:1
or sm#/lg# x 100 for # in every 100 ex. 18 per 100
|Rate|| A measure of the frequency with which an event occurs in a defined population over a specified period of time. |
ie, how fast something is happening or going.
The comparison of a part to the whole.
189 diabetic men of 3,151 men =3,340...189/3,3340 x100 =5.66%
|Frequency Measures|| Compares one part of the distribution to another part of the distribution, or to the entire distribution.|
Includes ratios, proportions, and rates.
|Incidence Rate (person-time rate)|| |
A measure of incidence that incorporates time directly into the denominator.
Typically, each person is observed from start until one of four "end points": onset of disease, death, migration out of the study ("lost to follow-up"), or the end of the study.
|Mortality Rate|| A measure of the frequency of occurrence of death in a defined population during a specified interval.|
When mortality rates are based on vital statistics (e.g., counts of death certificates), the denominator most commonly used is the size of the population at the middle of the time period.
|Morbidity Rate|| A measure of the frequency of occurrence of illness in a defined population during a specified interval.|
Same concept as Mortality Rate, but measures illness instead of death.
|Attack Rate||The proportion of the population that develops illness during an outbreak. ex, 20 of 130 persons developed diarrhea after attending a picnic.|
|Primary Attack Rate|| The risk of getting the disease during a specified period, such as the duration of an outbreak. |
Synonymous with 'risk'
|Secondary Attack Rate|| |
Calculated to document the difference between community transmission of illness versus transmission of illness in a household, barracks, or other closed population.
|Incidence Proportion|| The proportion of the population that develops illness during an outbreak.|
More accurate phrase than 'attack rate'.
|Point Prevalence||The prevalence measured at a particular point in time. It is the proportion of persons with a particular disease or attribute on a particular date.|
|Age adjusted Mortality Rates||sfsf|
|Risk Ratio (relative risk)|| |
Compares the risk of a health event (disease, injury, risk factor, or death) among one group with the risk among another group.
A risk ratio of 1.0 indicates identical risk among the two groups.
|Crude Fertility Rate||fwerfw|
|Crude Birth Rate||sefsf|
|Low Birth Weight Ratio||fvs|
|Years of Potential Life Lost||fwef|
|Case Fatality Rates|| |
The proportion of persons with the disease who die from that disease.
Measures the severity of the disease.
|Death to Case Ratios||sfs|