Statistical Methods

Incidence and Death Rates

Ideally, crude, age-adjusted, and age-specific rates are used to plan for population-based cancer prevention and control interventions.

Confidence Intervals

Confidence intervals reflect the range of variation in estimating cancer rates. The width of a confidence interval depends on the amount of variability in the data.

Relative Cancer Survival

Surveillance of cancer incidence and survival are essential in monitoring and understanding CDC’s efforts to support the needs of cancer survivors.

Cancer Prevalence

Prevalence helps identify the level of disease burden on the population and health care system. It is a function of both incidence and survival.

Risk Factor-Associated Cancers

Although cancer represents many heterogeneous diseases, some cancer types share common risk factors. Because risk factor information is not routinely collected by cancer registries, estimates for risk factor-associated cancers often are based only on cancer type. Using these standard definitions for risk factor-associated cancers can help facilitate comparisons of cancer burden across states and communities.

Incidence and Death Estimates by Congressional District

Cancer death rates and counts for 2011–2015 were estimated for the 436 federal congressional districts according to the boundaries for the 115th Congress of the United States. Cancer incidence rates and counts were estimated for 424 federal congressional districts.

Suppression of Rates and Counts

When the numbers of cases or deaths used to compute rates are small, those rates tend to have poor reliability. Another important reason for using a threshold value for suppressing cells is to protect the confidentiality of patients whose data are included in a report by reducing or eliminating the risk of disclosing their identity.