Sample Sudaan Code

Program Function

Produces means, standard error of means, 95 percent confidence limits and design, standard deviations which account for the complex sample.

This program creates a file for input into PROC DESCRIPT by merging the file containing the analytic variable of interest, in this case serum total cholesterol, with the demographic file containing the design variables. That is, the full sample weight and the 52 replicate weights as well as age and gender.

Written By:
CDC/NCHS/DHES

Date
August 30, 2002

Notes

Please follow these steps to download the correct file from the NHANES Website and then merge the data file with selected variables from the demographics file: 

1.  Create a folder on your PC titled "C:\My Files\Temp"

2.  In a suitable web browser, go to    http://www.cdc.gov/nchs/about/major/nhanes/ NHANES99_00.htm

3.  Find the "Lab13 Total Cholesterol" link under the "Laboratory Files" area and click on it.  If prompted for a location to download the file to, specify "C:\My Files\Temp".  This will start downloading a self-extracting file, "Lab13 Total Cholesterol.exe" to your machine.

Execute this file once the download is complete. After executing this file a new window will appear on your screen asking where to extract files to.  Specify "C:\My Files\Temp".  Then hit the "extract" button at the bottom left of this window. This action will result in three files in "C:\My Files\Temp": Lab13.pdf (codebook),  Lab13.xpt (SAS transport file), and Lab13DOC.pdf (Lab13 documentation).

4.  Return to the web browser.  Find the "Demographics" link under the "Demographics File" area and click on it.  If prompted for a location to download the file to, specify "C:\My Files\Temp".  This will start downloading a self-extracting file, "demo.exe" to your machine. Execute this file once the download is complete. After executing this file a new window will appear on your screen asking where to extract files to.  Specify "C:\My Files\Temp". Then hit the "extract" button at the bottom left of this window. This action will result in three files in "C:\My Files\Temp":    DEMO.pdf (codebook), DEMO.xpt(SAS transport file), and DEMODOC.pdf (Demographics documentation).

5.  Start your version of the SAS program.  Next copy and paste the SAS program provided below to the SAS program editor window, then click on the Run icon on your SAS toolbar. 

LIBNAME L XPORT 'C:\My Files\Temp\LAB13.xpt';

LIBNAME D XPORT 'C:\My Files\Temp\DEMO.xpt';

**Creates a file for input into PROC DESCRIPT**;

data demo;
 set d.demo;
run;
proc sort data=demo;
by seqn;
run;
data chol;
set l.lab13;
run;
proc sort data=chol;
by seqn;
run;
proc format;
 value gender 1='Men'
                     2='Women';

run;
data comb;
merge demo chol;
   by seqn; 
   label lbxtc='Serum total cholesterol'
   riagendr='Gender'; 
   stratum=1; 
  age1=1+(ridageyr>39)+(ridageyr>59);
run;

**Produces means, standard error of means, 95 percent confidence limits and design, standard deviations which account for the complex sample**;

proc descript data=comb design=jackknife deft;

subpopn ridageyr>=20 & wtmec2yr>=1; 
**Use wtint2yr for variables based on interview data**;
weight wtmec2yr; 
**Use wtirep01-wtirep52 for variables based on interview data**;
jackwgts wtmrep01-wtmrep52/adjjack=.980769; 

subgroup age1 riagendr; 
levels 3 2; 
var lbxtc; 
table riagendr*age1; 
print nsum mean semean deffmean/style=NCHS nsumfmt=f8.0 
meanfmt=f8.0 semeanfmt=f8.1;
rtitle "Mean serum total cholesterol of adults 20 years of age and older: United States, 1999-2000"; 
rformat riagendr gender.;
run;

This page last reviewed January 11, 2007