What is NHANES?
National Health and Nutrition Examination Surveys (NHANES) data provide a snapshot of the health and nutrition of the U.S. population.more
As a part of the Centers for Disease Control and Prevention (CDC), the National Center for Health Statistics (NCHS) conducts the National Health and Nutrition Examination Surveys (NHANES). NHANES is the only national survey that collects extensive health information from both face-to-face interviews and medical examinations. Data from NHANES surveys have provided unique opportunities to study major nutrition, infection, environmental, and chronic health conditions in the U.S.
In 2000, NCHS made NHANES datasets publicly available on its website. Since then, a growing number of analysts have taken advantage of this unique opportunity to study major health conditions in the U.S.
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Why was this tutorial created?
NCHS and the National Cancer Institute (NCI) developed this web-based tutorial to meet the growing demands of NHANES data users and to promote broader and more proficient use of NHANES data.more
Novice or experienced, all users face similar challenges due to the complexity of the survey design and vast amount of information available in NHANES data. All users need to learn how to:
- efficiently locate pertinent information on the NCHS website, which is constantly updated and evolving;
- quickly retrieve NHANES data files and variables, given the complex structure and vast amount of the data available; and
- correctly conduct intended statistical analyses with appropriate attention paid to the nuances of NHANES data, given its complex sample design, weighting requirements, and data structure.
What does the tutorial provide?
To best serve the needs of a wide range of users, the tutorial has included as much information as possible to make it a complete on-line learning course.more
The tutorial simulates a real life experience of how to conduct an analytical project from beginning to end, with a step-by-step logical flow through typical analytic procedures. Relevant NHANES data information and nuances, tips and explanations for SAS or SUDAAN programs, downloadable sample program code, and analytical guidance are organized and integrated into different modules and tasks to facilitate this learning process.
The tutorial is intended to be:
- a step-by-step course on NHANES data retrieval and analysis for new users;
- a self-learning tool for novice and infrequent users to supplement their knowledge of the NHANES database and the analysis techniques required to properly analyze this complex dataset; and
- a reference for experienced researchers highlighting NHANES analytic nuances and sample program code.
What's the best way to use the tutorial?
Your own background and learning style will dictate how you can best use this tutorial.more
- If you are a beginner, you may want to do the tutorial in a linear fashion, starting with the modules that orient you to the survey, then progressing through modules on how to prepare an analytic dataset and how to conduct various types of analyses.
- If you are an experienced NHANES user who is searching for specific information or types of assistance, you can pick and choose topics among the modules or even among tasks within modules.
Use the tutorial's features and content to suit your own purposes:
- a linear path for users who need step-by-step self-guided training;
- index pages and easy navigation throughout modules that allow you to limit your training to information on an "as needed" basis;
- checklists, summary tables, and animated demonstrations with audio explanation to enhance learning;
- real-life examples to assist you through the various processes of data preparation and data analysis;
- sample code and data files for you to practice skills and run analyses using your own software;
- annotated results with interpretation and comments on commonly made mistakes, to help you troubleshoot your own analyses; and
- related links to outside resources, including training for prerequisite skills; and supplemental information for experienced users.
Who is the audience?
We expect users of this tutorial will have different levels of experience with NHANES data and varied degrees of skill in statistics and software packages.more
- public health and other government staff involved in NHANES analyses;
- research and education community analysts who use NHANES for scientific studies or education purposes;
- public health and medical professionals who use NHANES data for planning, policy making or public health programs; and
- other users of NHANES statistics or groups interested in NHANES.