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Methods and Software: Cancer Mortality
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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.
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