The Interquartile Range (IQR) is a measure of statistical dispersion, or how spread out the values in a data set are. It is calculated as the difference between the third quartile (Q3) and the first quartile (Q1), effectively capturing the range within which the middle 50% of the data points lie. In the context of Epidemiology, the IQR is particularly useful for summarizing continuous data such as age, blood pressure, or duration of an illness.
