Task 2: How to Identify and Recode Skip Patterns in NHANES III

The second task is to check the data for skip patterns. To do this, you will use the:

 

Step 1: Check codebook for skip patterns

Check the codebook to determine if a skip pattern affects the variables in your analysis. See the Locate Variables module Task 1 for more information on how to locate background information on variables in the documentation.

 

Skip Patterns in Blood Pressure Questionnaire Codebook

picture of skip pattern in questionnaire

Step 2: Check data for skip patterns

After you have used the codebook to discover if a skip pattern affects variables in your analysis, you will use cross tabulations obtained by the SAS proc freq procedure to determine the presence of skip patterns.

Program to Check Data for Skip Patterns

Statements Explanation

Proc freq data =demo2_nh3;

Use the proc freq procedure to determine the frequency of each value of the variables listed.
where hsageu=2 and hsageir>= 20 and dmpstat=2 ;