# Hypothesis Testing when using the NHANES-CMS linked data

### Purpose

The t-test and chi-square statistics are used to test statistical hypotheses about population parameters. This module will demonstrate the use of these statistics in NHANES data analysis.

### Task 1: Use the t-test statistic

The t-test is used to test the null hypothesis that the means or proportions of two population subgroups are equal OR that the difference between two means or proportions equals zero when the estimates are based on a small probability sample. When using a simple random sample, small is defined as less than 30.

- Key Concepts about Using the t-Test Statistic in NHANES
- How to Set Up a t-test in NHANES Using SUDAAN
- How to Set Up a t-test in NHANES Using SAS 9.1 Survey Procedures
- How to Set Up a t-test in NHANES Using SAS 9.2 Survey Procedures
- How to Set Up a t-test in NHANES Using Stata
- How to set up a t-test using NHANES-CMS linked data in SUDAAN

### Task 2: Perform chi-square test

The chi-square test is used to test the association between two variables cross-classified in a two-way table and the homogeneity of their association.

- Key Concepts about Using the Chi-Square Test in NHANES
- How to Perform a Chi-Square Test in NHANES Using SUDAAN
- How to Perform a Chi-Square Test in NHANES Using SAS Survey Procedures
- How to Perform a Chi-Square Test in NHANES Using Stata
- How to perform a chi-square test using NHANES-CMS linked data in SUDAAN

##### Contact Us:

- National Center for Health Statistics

3311 Toledo Rd

Hyattsville, MD 20782 - 1 (800) 232-4636
- cdcinfo@cdc.gov