USING SAS WITH NAMCS DATA
   
  There are two ways to read the 2016 NAMCS public use data file using SAS:

  Option 1 - Use the zipped file namcs2016_sas.zip in the SAS folder on 
  the FTP server to open a complete SAS dataset of the 2016 NAMCS public use file.

  The steps for this option are as follows:

  1) Create a new folder on your local workstation, for example, C:\MYFILES\NAMCS2016

  2) Download to the new folder the file namcs2016_sas.zip and the file nam16for.txt 
     from the FTP server: ftp://ftp.cdc.gov/pub/Health_Statistics/NCHS/dataset_documentation/namcs/sas

  3) namcs2016_sas.zip is a compressed file which you must unzip prior to use. 
     In order to do this, double click on the file name in your directory screen; 
     an option to unzip the file should appear. Once you have selected the unzip option, 
     a new unzipped file called namcs2016_sas.sas7bdat should appear. This is the SAS 
     dataset. You can then move the file to your preferred location.

     nam16for.txt is the file containing the formats which you will need to include in your
     program in order for the SAS file to run.  

  4) To use the SAS dataset, the following code provides an example for a file saved to C:\MyFiles\NAMCS2016:

     %inc "C:\MyFiles\NAMCS2016\nam16for.txt";  /*read in the SAS formats*/
     libname out1 'C:\MyFiles\NAMCS2016';  /*point to file location on your workstation*/
     data test16; set out1.namcs2016_sas;  /*create a temporary working file copied from the unzipped file*/
     proc surveyfreq data=test16;
     tables sex*ager /clwt cl;
     cluster cpsum;
     strata cstratm;
     weight patwt;
     run;
 
  Option 2 - Use the SAS input, label and format files provided to create your own SAS data set. 

  The steps for this option are as follows:

  1) Create a new folder on your local workstation, for example, C:\MYFILES\NAMCS2016

  2) Download to the new folder the 2016 NAMCS ASCII dataset (namcs2016.zip) from the FTP server: 
     ftp://ftp.cdc.gov/pub/Health_Statistics/NCHS/datasets/namcs

  3) namcs2016.zip is a compressed file which must be unzipped prior to use.
     In order to do this, double click on the file name in your directory screen; 
     an option to unzip the file should appear. Once you select the unzip option, a new file 
     called namcs2016 should appear.  This is the unzipped NAMCS ASCII dataset and has no file 
     extension. You can then move the file to your preferred location. 

  4) Download to the new folder the nam16inp.txt, nam16lab.txt and nam16for.txt files from the FTP server:
     ftp://ftp.cdc.gov/pub/Health_Statistics/NCHS/dataset_documentation/namcs/sas

  5) Sample SAS code is shown below; other examples can be found here: 
     https://www.cdc.gov/nchs/ahcd/ahcd_presentations.htm

     filename nam16pub "C:\MyFiles\NAMCS2016\namcs2016";        /*unzipped ASCII data set*/
     filename nam16for "C:\MyFiles\NAMCS2016\nam16for.txt";     /*SAS format statement*/
     filename nam16inp "C:\MyFiles\NAMCS2016\nam16inp.txt";     /*SAS input statement*/
     filename nam16lab "C:\MyFiles\NAMCS2016\nam16lab.txt";     /*SAS label statement*/

     %inc nam16for;  /*reads in the formats*/

     data test16; 
     infile nam16pub missover lrecl=9999;
     %inc nam16inp;  /*reads in the input statement*/
     %inc nam16lab;  /*reads in the labels*/
     run;

     proc surveyfreq data=test16;
     tables sex*ager /clwt cl;
     cluster cpsum;
     strata cstratm;
     weight patwt;
     run;


   CAUTION - Because the NAMCS is a sample survey, the application of 
   weights to the sample data is REQUIRED to produce national estimates
   of office visits, as well as to accurately assess the sampling error of
   statistics based on the survey data.  Please refer to the appropriate
   sections of the documentation file for information on how to apply the 
   weights and to obtain relative standard errors of national estimates.
                                                                                                
   For questions, suggestions, or comments concerning NAMCS data, please
   contact the Ambulatory and Hospital Care Statistics Branch at 
   (301) 458-4600 or by email at ambcare@cdc.gov. 

   For additional information on NCHS data products, please call CDC-INFO at 
   800-CDC-INFO (800-232-4636), TTY (888-232-6348), Monday-Friday 8am-8pm EST, 
   or use the CDC-INFO online request form at https://www.cdc.gov/info.