UNITS Statement
- UNITS independent1 = list1 < ...independentk = listk > <
/option > ;
The UNITS statement enables you to specify units of change for the
continuous explanatory variables so that customized odds ratios can be
estimated.
An estimate of the corresponding odds ratio is produced
for each unit of change specified for an explanatory variable.
The UNITS statement is ignored for CLASS variables.
If the
CLODDS= option is specified in the MODEL
statement, the corresponding
confidence limits for the odds ratios are also displayed.
The term independent is the name of an explanatory variable and
list represents a list of units of change, separated by spaces,
that are of interest for that variable. Each unit of change in a list
has one of the following forms:
- number
- SD or -SD
- number * SD
where number is any nonzero number, and
SD is the sample standard deviation of the corresponding independent
variable. For example, X = -2 requests
an odds ratio that
represents the change in the odds when the variable X is
decreased by two units. X = 2 *SD requests an estimate of
the change in the odds when X is increased by two sample standard
deviations.
You can specify the following option in the UNITS statement after
a slash(/).
- DEFAULT= list
-
gives a list of units of change for all explanatory variables that are
not specified in the UNITS statement. Each unit of change can be in any
of the forms described previously.
If the DEFAULT= option is not specified, PROC LOGISTIC does not
produce customized odds ratio estimates for any explanatory variable
that is not listed in the UNITS statement.
For more information, see the "Odds Ratio Estimation" section.
Copyright © 1999 by SAS Institute Inc., Cary, NC, USA. All rights reserved.
