```.-
help for ^regpred^
.-

Linear regression predictions  (Joanne M. Garrett  05/08/98)
-----------------------------

^regpred^ yvar xvar [^if^ exp]^,^ [^f^rom^(^#^) t^o^(^#^) i^nc^(^#^) cl^ass^
> (^classvar^)^
^l^evel^(^#^)^ graph_options]

^regpred^ calculates and prints predicted values and 95% confidence intervals
from linear regression estimates for a continuous X variable, adjusted for
covariates.  Default prints predicted values and confidence intervals; model
estimates and graph can be shown. Optionally a quadratic or a quadratic and
cubic term can be added to the model. An interaction between X and a nominal
variable can be estimated and graphed. Dummy variables are created for the
nominal variable with the lowest category defaulting to the reference group.

Variables and options required
------------------------------

yvar -- dependent variable  (continuous)
xvar -- continuous independent variable (interval or ordinal)
^f^rom^(^#^)^ -- bottom value for xvar
^t^o^(^#^)^ -- top value for xvar
^i^nc^(^#^)^ -- increment size between bottom and top values (defaults to 1
> )

Options allowed
---------------

^cl^ass^(^classvar^)^ -- nominal variable for a xvar by classvar interactio
> n
> ubic
(will not work with the class option)
estimates reported); Covariates set to their mean,
based on observations used in the analysis, or can be
set to user specified values (e.g., age=50 gender=1)
^m^odel -- displays the regression table
^gr^aph -- displays graph of predicted values and 95% confidence intervals;
if class is requested, confidence intervals are not displayed
^nol^ist -- does not print list of predicted values and 95% CIs
^l^evel^(^#^)^ -- specifies the confidence level, in percent, for calculati
> on
of confidence intervals (default=95%)

Examples
--------

. ^regpred chol age, from(20) to(80) inc(5) adj(sys hra) model^

Calculates the predicted cholestorol values for 5 year increments of
age from 20 years to 80 years (i.e., age=20,25,30,...,80) adjusted for
systolic blood pressure and heart rate; displays model and predicted
values, but does not display graph

. ^regpred chol sys, f(60) t(300) i(20) adj(age hra) graph ylab xlab^

Calculates the predicted cholestorol values for systolic blood pressure
readings from 60 to 300 in 20 mm/hg increments, adjusted for age and
heart rate; displays graph and list of predicted values

. ^regpred chol sys, f(60) t(300) i(20) adj(age hra) class(race) graph^

Calculates the predicted cholestorol values for systolic blood pressure
readings from 60 to 300 in 20 mm/hg increments, adjusted for age and
heart rate, by categories of race; displays an F test for interaction;
graphs the results

. ^regpred chol age, f(40) t(80) poly(3) adj(sys=180) graph xlab ylab nolist^

Calculates the predicted cholestorol values for 1 year increments of
age; terms for age-squared and age-cubed included in model using the
poly(3) option; also adjusted for systolic blood pressure of 180;
displays graph; does not list predicted values and CIs

Note
----
Covariates are set to their mean based on observations used
in the analysis
```