Methods and Software: Cancer Mortality
A cancer mortality rate is the number of reported cancer deaths of a specific site/type occurring in a specified population during a year (or group of years), usually expressed as the number of cancers per 100,000 population at risk. Several statistical methods and software tools have been developed for the analysis and reporting on cancer mortality statistics.
SEER*Stat Statistical Methods
SEER*Stat is statistical software for the analysis of SEER and other cancer-related databases. The following methods associated with the reporting of basic cancer mortality statistics are added directly to SEER*Stat.
- Age-Adjusted Rates - An age-adjusted mortality rate is a weighted average of the age-specific mortality rates, where the weights are the proportions of persons in the corresponding age groups of a standard million population.
- Gamma Confidence Intervals for Age-Adjusted Rates
: This method provides confidence intervals with good statistical properties even when the cancer is rare, the population is small, or the population of interest is very different from the standard.
Reference: Fay MP, Feuer EJ. Confidence intervals for directly standardized rates: A method based on the Gamma distribution. Statistics in Medicine 1997;16:791-801. - Trends in Rates - Trends over time based on frequencies (percent change, annual percent change)
- Incidence-based Mortality - The incidence-based mortality rate allows a partitioning of mortality by variables associated with the cancer onset.
Joinpoint Trend Analysis Software
Joinpoint is statistical software for the analysis of trends using joinpoint models, that is, models with several different lines that are connected at the "joinpoints." The software takes trend data (e.g., cancer rates) and fits the simplest joinpoint model that the data allows. This enables the user to test whether an apparent change in trend is statistically significant. See the Joinpoint Web site for more information and to download the software.
DevCan - Probability of Developing or Dying of Cancer
The DevCan software uses lifetable methods to compute the lifetime and age-conditioned probability of developing cancer and dying of cancer in the general population. Input data for the computations include cancer mortality rates as well as all-cause mortality rates. Data sets are supplied to estimate risks of developing and dying of cancer for over 20 cancer sites by race and sex. The Probability of Developing or Dying of Cancer Web site provides access to the DevCan software as well as links to published statistics and documentation of the methodology. In addition, the Cancer Query Systems: Probability of Developing or Dying from Cancer provides access to a database of pre-calculated statistics.
