Derived data is information gather from or about the individual subject.
Derived data is
a set of values that reflect the character of the source data, but which hide the exact original values. This is usually done by using banding techniques to produce coarser-grained descriptions of values than in the sourcedataset e.g. replacing dates of birth by ages or years, addresses by areas of residence or wards, using partial postcodes or rounding exact figures so they appear in a normalised form.