 | SEER*Stat Trends Exercise 1a
Problem Statement
Examine trends in age-adjusted incidence rates for malignant colon (excluding rectum)
cancer for males in the SEER 9 Registries for 1975-2005. Use rates, age-adjusted to the
2000 US Standard Population in the trend calculations.
Specifically, calculate the Percent Change (PC) and Annual Percent Change (APC) for the
entire time period 1975-2005.
Key Points and Reminders
To calculate the percent change and annual percent change in rates, you must select
one of the "Trends" options in the Statistic box on the Statistic Tab. The time periods used for the trend
calculations are specified as groupings in a "Trend Variable". The "Year of diagnosis"
and user-defined variables derived from "Year of diagnosis" are the only possible
incidence trend variables. APCs and PCs will be calculated for groupings with three or
more consecutive years. The rates for the individual years within these time periods will
always be displayed in the output (it is not necessary to define groupings for the
individual years). Groupings of 1 or 2 years will be ignored.
In this exercise, you will calculate trends in rates for cases diagnosed between 1975-2005, the only years for which
all 9 registries have cases in the database. Though the database used has data for cases diagnosed starting with 1973,
the Seattle-Puget Sound and Atlanta registries joined the SEER program in 1974 and 1975, respectively.
By default, APCs are calculated in SEER*Stat using the Weighted Least Squares method.
Standard errors are required to calculate APCs using this method and, therefore, are
always included with the results.
Step 1: Create a New Rate Session
- Start SEER*Stat.
- From the File menu, select New > Rate Session, or use the
on the toolbar.
Step 2: Data Tab
On the Data Tab:
- Select the database "Incidence - SEER 9 Regs Limited-Use, Nov 2007 Sub (1973-2005) <Katrina/Rita Population Adjustment>".
Step 3: Dictionary
It is necessary to create a new trend variable based on year of diagnosis. This database contains data from 1973 through 2005, but we want to examine trends from 1975-2005.
- Use the
 ,
or select Dictionary from the File menu, to open the Dictionary.
- Open the "Race, Sex, Year Dx, Registry, County" folder, click on the "Year of diagnosis" variable, then click
Create.
- Name the new variable "Year of diagnosis (1975-2005)".
- Delete the 1973 and 1974 groupings.
- Highlight the 1973-2005 grouping and change the range of values to 1975 through 2005, then click Update. Title the new
grouping "1975-2005".
- To highlight a continuous range of values, click on the first value in the range, then hold down your SHIFT key
while you click on the last value in the range.
Step 4: Statistic Tab
Choose the following settings on the Statistic tab. Most of these settings are the default values.
- Set the Statistic to Trends (Age-Adjusted). The other controls you need to use on this
tab will not all be available until you choose this option.
- The Standard Population should be "2000 US Std Population (19 age groups - Census P25-1130)".
- The Age Variable should be "Age recode with <1 year olds".
- The Trend Variable should be the new variable you created, "Year of diagnosis (1975-2005)". All available variables based on year of diagnosis will be listed in the Trend Variable selection list.
- The PC End Points should be One Year.
- The APC Calculation method should be Weighted Least Squares.
- The Tiwari Modification for confidence intervals should be used.
Step 5: Selection Tab
On the Selection tab:
- Mark only the Malignant Behavior checkbox in the Select Only section.
- Edit the "Race, Sex, Year Dx, Registry, County (Pop, Case Files)" selection statement to read:
{Race, Sex, Year Dx, Registry, County.Sex} = 'Male'
AND {Race, Sex, Year Dx, Registry, County.Year of diagnosis} = '1975','1976','1977','1978','1979','1980','1981','1982',
'1983','1984','1985','1986','1987','1988','1989','1990','1991','1992','1993','1994','1995','1996',
'1997','1998','1999','2000','2001','2002','2003','2004','2005'
- Edit the "Other (Case Files)" selection statement to read:
{Site and Morphology.Site rec with Kaposi and mesothelioma} = 'Colon excluding Rectum'
It is not necessary to include the "SEER registry" in the
selection statement, since we are interested in trends in all registries covered by the database.
Step 6: Table Tab
There are no table variables required. The trend variable, "Year of Diagnosis", will automatically be displayed in the output matrix as a row variable.
Step 7: Output Tab
- Give your matrix a title, such as:
Malignant Male Colon Cancer Incidence Trends
SEER 9, 1975-2005
Trends Exercise 1a
Step 8: Execute the Session
- Use the
 ,
or select Execute from the Session menu, to execute
the session.
A dialog will display the progress of the job. When the job completes, a new window will open
containing the output matrix.
Step 9: Check Your Results
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