Changes in risk can be expressed in relative or absolute terms.

Risk is the likelihood that an event will occur.It can be expressed
as either a percentage—for example, that heart attacks
occur in 11% of men between the ages of 60 and 79—
or as a rate— that one in two million divers along Australia’s western coast will suffer a fatal shark bite each year.These numbers express the absolute risk of heart attacks
and shark attacks in these groups.Changes in risk can be expressed in relative or absolute terms.