Component Description
The MEC phlebotomist administered a questionnaire to determine the fasting status of the survey participant.
Eligible Sample
Examined participants aged 1 year and older were eligible.
Description of Laboratory Methodology
The MEC phlebotomist administered a questionnaire to determine the fasting status of the survey participant.
There were no changes to the questionnaire or lab site.
Laboratory Quality Assurance and Monitoring
The NHANES quality control and quality assurance protocols (QA/QC) meet the 1988 Clinical Laboratory Improvement Amendments mandates. Detailed QA/QC instructions are discussed in the NHANES Laboratory Procedures Manual (LPM). Detailed
instructions on specimen collection and processing are discussed in the NHANES Laboratory Procedures Manual (LPM).
Data Processing and Editing
Fasting questionnaire data were recorded directly into a computerized database; all forms used in the MEC were automated.
Analytic Notes
Refer to the 2013-2014 Laboratory Data Overview for general information on NHANES laboratory data.
The analysis of NHANES 2013-2014 laboratory data must be conducted using the appropriate survey design and demographic variables. The NHANES 2013-2014 Demographics File contains demographic data, health indicators, and other related information collected during household interviews as well as the sample weight variables. This Fasting Questionnaire File includes auxiliary information such as fasting status, the time of venipuncture, and the conditions precluding venipuncture. The demographics and fasting questionnaire files may be linked to the laboratory data file using the unique survey participant identifier (i.e., SEQN).
Use PHAFSTHR and PHAFSTMN to determine the duration of fasting in hours and minutes, respectively. When calculating a fasting time in hours and minutes, pay careful attention to the other times in hours and minutes. For example, the survey participants were asked: "When was the last time you ate or drank anything other than plain water? Do not include diet soda or black coffee or tea with artificial sweeteners like Sweet'N Low, NutraSweet, Equal, or Splenda." Survey participants were then asked questions PHQ020 to PHQ060: "Have you had any of the following since the last time you ate or drank anything other than plain water? Coffee or tea with cream or sugar (iInclude milk or non-dairy creamers); Alcohol, such as beer, wine, or liquor; Gum, breath mints, lozenges, cough drops, or cold remedies; Antacids, laxatives, or anti-diarrheal; Dietary supplements such as vitamins and minerals."
If you are using fasting status in any of your analyses, please consider the answers to PHACOFHR/PHACOFMN, PHAALCHR/PHAALCMN, PHAGUMHR/PHAGUMMN/ PHAANTHR/PHAANTMN, and PHASUPHR/PHASUPMN with the times in hours and minutes in addition to the PHAFSTHR and PHSFSTMN times.
Use PHDSESN to determine the session in which the participant was examined.
MEC Exam sample weights should be used for analyses. Please refer to the NHANES Analytic Guidelines and the on-line NHANES Tutorial for further details on the use of sample weights and other analytic issues.