Rates are the number of cancer cases (or deaths) divided by the number of
people in the state and are usually expressed as the number of cases (or
deaths) per 100,000 people. Rates are useful for comparing the cancer risk in
different populations. Some caution needs to be exercised when using rates,
however. Because cancer is more common in older people than in younger people,
communities with a large elderly population will have higher cancer rates than
a community with many younger people. In order to control for differences in
the age structure of different populations, the CCR age-adjusts the rates so
that valid comparisons can be made from year to year and from one geographic
area to another. This procedure removes the effect of the different age
structures of the populations being compared.
One other caution needs to be mentioned. The age-adjusting procedure
requires the use of a "standard" population. Various standard
populations have been used for age-adjusting. The two most commonly used have
been the 1940 and the 1970 US populations. Other countries have used other
standard populations. Federal government agencies have recently begun using
the Year 2000 projected population for age-adjusting their data. The data
presented here use this population for age-adjusting. Comparisons with
age-adjusted data from other sources are valid only if the "standard
population" used in the calculations is the same.
If you have questions about these data or about other cancer data for North
Carolina, you may call (919) 715-4574.