Task 4: How to Identify Environmental Chemical Laboratory Methods and Corresponding Coefficient of Variation (CV) and Their File Locations

Warning iconThe steps below assume that you are already familiar with the laboratory documentation and method files available from the NHANES website. If you need information about how to locate and download documentation and method files, please review the Locate Variables module in the Continuous NHANES Web Tutorial before continuing.

Phthalate Data (1999-2004):

To identify general laboratory information, view the General Documentation. This documentation is available on the Laboratory data page for each survey cycle. View the General Lab Documentation for NHANES 2003-2004 [PDF - 447 KB].

Since 2003, a summary of the environmental chemicals tested and the type of specimen used for testing has been available on the NHANES website. This document is called the Environmental Health Profile and is located under the Laboratory Components heading on the Survey Questionnaires, Examination Components and Laboratory Components page for each survey cycle. View the NHANES 2003-2004 Environmental Health Profile [PDF - 154 KB].

To view detailed information for each analyte during each survey cycle, you will need to view the Laboratory Procedure Manual. These manuals provide the measure of the method’s coefficient of variation (CV) in the back of each manual.

CV    =              standard deviation                    
                      mean of the quality control results

The link to the laboratory procedure manuals list can be found on the Laboratory Data page for each survey cycle. For this example, please review the Laboratory Procedure Manual for the 2003-2004 urine phthalate metabolites [PDF - 303 KB]).


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