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SPSS® 12.0 Command Syntax Reference

SPSS® 12.0 Command Syntax Reference

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SURVIVAL 1555<br />

one for censored cases and one for uncensored cases. The number of cases included on each<br />

record is used as the weight factor. If control variables are used, there will be up to two<br />

records (one for censored and one for uncensored cases) for each value of the control variable<br />

in each interval. These records must contain the value of the control variable and the number<br />

of cases that belong in the particular category as well as values for survival time and status.<br />

Example<br />

DATA LIST / SURVEVAR 1-2 STATVAR 4 SEX 6 COUNT 8.<br />

VALUE LABELS STATVAR 1 ’DECEASED’ 2 ’ALIVE’<br />

/SEX 1 ’FEMALE’ 2 ’MALE’.<br />

BEGIN DATA<br />

1 1 1 6<br />

1 1 1 1<br />

1 2 2 2<br />

1 1 2 1<br />

2 2 1 1<br />

2 1 1 2<br />

2 2 2 1<br />

2 1 2 3<br />

...<br />

END DATA.<br />

WEIGHT COUNT.<br />

SURVIVAL TABLES = SURVEVAR BY SEX (1,2)<br />

/INTERVALS = THRU 10 BY 1<br />

/STATUS = STATVAR (1) FOR SURVEVAR.<br />

• This example reads aggregated data and performs a SURVIVAL analysis when a control<br />

variable with two values is used.<br />

• The first data record has a code of 1 on the status variable STATVAR, indicating that it is<br />

an uncensored case, and a code of 1 on SEX, the control variable. The number of cases for<br />

this interval is 6, the value of the variable COUNT. Intervals with weights of 0 do not have<br />

to be included.<br />

• COUNT is not used in SURVIVAL but is the weight variable. In this example, each interval<br />

requires four records to provide all of the data for each SURVEVAR interval.<br />

MISSING Subcommand<br />

MISSING controls missing-value treatments. The default is GROUPWISE.<br />

• Negative values on the survival variables are automatically treated as missing data. In<br />

addition, cases outside the value range on a control variable are excluded.<br />

• GROUPWISE and LISTWISE are mutually exclusive. However, each can be used with<br />

INCLUDE.<br />

GROUPWISE Exclude missing values groupwise. Cases with missing values on a variable<br />

are excluded from any calculation involving that variable. This is the default.<br />

LISTWISE Exclude missing values listwise. Cases missing on any variables named on<br />

TABLES are excluded from the analysis.<br />

INCLUDE Include user-missing values. User-missing values are included in the analysis.

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