Experimental event rate
Encyclopedia
In epidemiology
Epidemiology
Epidemiology is the study of health-event, health-characteristic, or health-determinant patterns in a population. It is the cornerstone method of public health research, and helps inform policy decisions and evidence-based medicine by identifying risk factors for disease and targets for preventive...

 and biostatistics
Biostatistics
Biostatistics is the application of statistics to a wide range of topics in biology...

, the experimental event rate (EER) is a measure of how often a particular statistical event (such as response to a drug, adverse event
Adverse event
An adverse event is any adverse change in health or side effect that occurs in a person who participates in a clinical trial while the patient is receiving the treatment or within a previously specified period of time after the treatment has been completed.AEs in patients participating in...

 or death) occurs within the experimental group (non-control group) of an experiment .

This value is very useful in determining the therapeutic benefit or risk to patients in experimental groups, in comparison to patients in placebo
Placebo
A placebo is a simulated or otherwise medically ineffectual treatment for a disease or other medical condition intended to deceive the recipient...

 or traditionally treated control groups.

Three statistical terms rely on EER for their calculation: absolute risk reduction
Absolute risk reduction
In epidemiology, the absolute risk reduction or risk difference is the decrease in risk of a given activity or treatment in relation to a control activity or treatment. It is the inverse of the number needed to treat....

, relative risk reduction
Relative risk reduction
In epidemiology, the relative risk reduction is a measure calculated by dividing the absolute risk reduction by the control event rate.The relative risk reduction can be more useful than the absolute risk reduction in determining an appropriate treatment plan, because it accounts not only for the...

 and number needed to treat
Number needed to treat
The number needed to treat is an epidemiological measure used in assessing the effectiveness of a health-care intervention, typically a treatment with medication. The NNT is the average number of patients who need to be treated to prevent one additional bad outcome...

.

Worked example

In a trial of hypothetical drug "X" where we are measuring event "Z", we have two groups. Our control group (25 people) is given a placebo
Placebo
A placebo is a simulated or otherwise medically ineffectual treatment for a disease or other medical condition intended to deceive the recipient...

, and the experimental group (25 people) is given drug "X".

Event "Z" in control group : 4 in 25 people
Control event rate
Control event rate
In epidemiology and biostatistics, the control event rate is a measure of how often a particular statistical event occurs within the scientific control group of an experiment ....

 : 4/25

Event "Z" in experimental group : 12 in 25 people
Experimental event rate : 12/25

Another worked example is as follows:

See also

  • Control event rate
    Control event rate
    In epidemiology and biostatistics, the control event rate is a measure of how often a particular statistical event occurs within the scientific control group of an experiment ....

  • Absolute risk reduction
    Absolute risk reduction
    In epidemiology, the absolute risk reduction or risk difference is the decrease in risk of a given activity or treatment in relation to a control activity or treatment. It is the inverse of the number needed to treat....

  • Relative risk reduction
    Relative risk reduction
    In epidemiology, the relative risk reduction is a measure calculated by dividing the absolute risk reduction by the control event rate.The relative risk reduction can be more useful than the absolute risk reduction in determining an appropriate treatment plan, because it accounts not only for the...

  • Number needed to treat
    Number needed to treat
    The number needed to treat is an epidemiological measure used in assessing the effectiveness of a health-care intervention, typically a treatment with medication. The NNT is the average number of patients who need to be treated to prevent one additional bad outcome...

The source of this article is wikipedia, the free encyclopedia.  The text of this article is licensed under the GFDL.
 
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