Below is a listing of all the sample code and datasets used in the NHANES II tutorial. They are organized by module and then task. If a module or task is not listed it is because it did not have a related program. All programs are SAS programs (i.e. SAS Survey Procedures or SAS-callable SUDAAN) and the datasets are SAS datasets for Windows.

Program code used in this tutorial follow procedures available in SAS 9.1 or SAS 8.0 and SUDAAN 9.0 or SUDAAN 8.0.

These programs use variable formats listed in the Tutorial Formats page. You may need to format the variables in your dataset the same way to reproduce results presented in the tutorial.

 

 

Download Data Files

• Task 3: How to Extract and Copy NHANES Data Files to Permanent Libraries
• Program to Extract and Create NHANES Datasets in Permanent Libraries

 

Keep & Merge Datasets

• Task 1: How to Keep NHANES II Data
  
  
  • NHANES II Adult Dataset
  • NHANES II Youth Dataset
  • NHANES II Lab Dataset
  • NHANES II Exam Dataset
  • Program to Directly Keep Datasets
  • Output of Program to Check Datasets Contents

   

• Task 2: How to Merge NHANES II Data
   
  • NHANES II Adult Dataset
  • NHANES II Youth Dataset
  • NHANES II Lab Dataset
  • NHANES II Exam Dataset
  • Program to Merge Data and Check Contents of Data
  • Output of Program to Sort Data, Merge Data, and Check Contents
  
  

Clean & Recode Data

• Task 1: How to Identify, Recode, and Evaluate Missing Data

 
• Step 1: Identify Missing and Unavailable Values
  • NHANES II Dataset
  • proc means
  • Output of Program to identify Missing and Unavailable Values
     
• Step 2: Recode Unavailable Values as Missing
  • NHANES II Dataset
  • Program to Assign Missing Values One Variable at a Time and by Group Using an Array
     
• Step 3: Evaluate Extent of Missing Data
  • NHANES II Dataset
  • Program to Check the Extent of Missing Data
  • Output of Program to Evaluate Extent of Missing Data
     

• Task 2: How to Check for Skip Patterns and Explain How they Affect Results
   
  • Step 2: Check Data for Skip Patterns
    • NHANES II Dataset
    • Program to Check Data for Skip Patterns
    • Output of Program to Check for Skip Patterns
       
  • Step 3: Recode Data as Necessary
    • NHANES II Dataset
    • Program to Directly Recode Variable and Check After Recoding and Create Derived Variable
    • Output of Program to Recode Skip Patterns
      
       
• Task 3: How to Check Distributions and Describe the Impact of Influential Outliers
   
  • Step 1: Check distributions by running univariate analysis
    • NHANES II Dataset
    • Program to Plot Distribution of Continuous Variable
    • Output of Program to Check Distributions
       
  • Step 2: Plot Graph of Survey Weight Against Distribution of Variable
    • NHANES II Dataset
    • Program to Plot Exam Weight Against Fasting Cholesterol
    • Output of Program to Plot Survey Weight against the Distribution of the Variable
       
  • Step 3: Identify Outliers and Compare Estimate with and without Outliers
    • NHANES II Dataset
    • Program to Create Dataset Without Outliers and Output Means of Both Datasets
    • Output of Program to Create Dataset without Outliers and Compare to Dataset with Outliers
      
       
• Task 4: How to Recode Variables
   
  • Step 1: Recode Based on Alternate Definitions
    • NHANES II Dataset
    • Program to Recode as Necessary Based on Alternate Definitions

     

  • Step 2: Check Derived Variables
    • NHANES II Dataset
    • Program to Check Recodes Using Cross Tabulations or proc means

    • Output of Program to Check Derived Variables