Table of Contents

Component Description

The objectives of this component are to:

  1. Provide data for monitoring secular trends in measures of nutritional status in the U.S. population;
  2. Evaluate the effect of people's habits and behaviors such as physical activity and the use of alcohol, tobacco, and dietary supplements on people's nutritional status; and
  3. Evaluate the effect of changes in nutrition and public health policies - including welfare reform legislation, food fortification policy, and child nutrition programs - on the nutritional status of the U.S. population.

These data will be used to estimate deficiencies and toxicities of specific nutrients in the population and subgroups, to provide population reference data, and to estimate the contribution of diet, supplements, and other factors to Whole Blood levels of nutrients. Data will be used for research to further define nutrient requirements as well as optimal levels for disease prevention and health promotion.

Eligible Sample

Participants aged 1 year and over were tested.

Description of Laboratory Methodology

The methods used to derive CBC parameters are based on the Beckman Coulter method of counting and sizing, in combination with an automatic diluting and mixing device for sample processing, and a single beam photometer for hemoglobinometry. The WBC differential uses VCS technology. See Chapter 7 of the NHANES Laboratory/Medical Technologists Procedures Manual (LPM) for details.

The Beckman Coulter MAXM instrument in the Mobile Examination Centers (MECs) produces a complete blood count on blood specimens and provides a distribution of blood cells for all participants.

There were no changes to the equipment, lab methods, or lab site from the previous 2 years.

A detailed description of the laboratory method used can be found on the NHANES website.

Data Processing and Editing

Blood specimens were measured at the NHANES MECs. Detailed specimen collection and processing instructions are discussed in the NHANES LPM. Read the LABDOC file for detailed data processing and editing protocols. The analytical methods are described in the Description of the Laboratory Methodology section.

This file contains no top coding.

Five derived variables were created in this data file. The formula for their derivation is as follows:

LBDLYMNO = LBXWBCSI * LBXLYPCT/100 (round to 1 decimal)
LBDMONO = LBXWBCSI * LBXMOPCT/100 (round to 1 decimal)
LBDNENO = LBXWBCSI * LBXNEPCT /100 (round to 1 decimal)
LBDEONO = LBXWBCSI * LBXEOPCT/100 (round to 1 decimal)
LBDBANO = LBXWBCSI * LBXBAPCT/100 (round to 1 decimal)

Detailed instructions on specimen collection and processing can be found on the NHANES website.

Laboratory Quality Assurance and Monitoring

The NHANES quality control and quality assurance protocols (QA/QC) meet the 1988 Clinical Laboratory Improvement Act mandates. Detailed quality control and quality assurance instructions are discussed in the NHANES LPM. Read the LABDOC file for detailed QA/QC protocols.

A detailed description of the quality assurance and quality control procedures can be found on the NHANES website.

Analytic Notes

The analysis of NHANES 2005–2006 laboratory data must be conducted with the key survey design and basic demographic variables. The NHANES 2005–2006 Household Questionnaire Data Files contain demographic data, health indicators, and other related information collected during household interviews. They also contain all survey design variables and sample weights for these age groups. The phlebotomy file includes auxiliary information such as the conditions precluding venipuncture. The household questionnaire and phlebotomy files may be linked to the laboratory data file using the unique survey participant identifier SEQN.

Codebook and Frequencies

SEQN - Respondent sequence number

Variable Name:
SEQN
SAS Label:
Respondent sequence number
English Text:
Respondent sequence number.
Target:
Both males and females 1 YEARS - 150 YEARS

LBXWBCSI - White blood cell count (1000 cells/uL)

Variable Name:
LBXWBCSI
SAS Label:
White blood cell count (1000 cells/uL)
English Text:
White blood cell count (1000 cells/uL)
Target:
Both males and females 1 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
2.3 to 55.9 Range of Values 8400 8400
. Missing 1040 9440

LBXLYPCT - Lymphocyte percent (%)

Variable Name:
LBXLYPCT
SAS Label:
Lymphocyte percent (%)
English Text:
Lymphocyte percent (%)
Target:
Both males and females 1 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
5.3 to 86.6 Range of Values 8378 8378
. Missing 1062 9440

LBXMOPCT - Monocyte percent (%)

Variable Name:
LBXMOPCT
SAS Label:
Monocyte percent (%)
English Text:
Monocyte percent (%)
Target:
Both males and females 1 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0.6 to 39.8 Range of Values 8378 8378
. Missing 1062 9440

LBXNEPCT - Segmented neutrophils percent (%)

Variable Name:
LBXNEPCT
SAS Label:
Segmented neutrophils percent (%)
English Text:
Segmented neutrophils percent (%)
Target:
Both males and females 1 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
6.6 to 92.7 Range of Values 8378 8378
. Missing 1062 9440

LBXEOPCT - Eosinophils percent (%)

Variable Name:
LBXEOPCT
SAS Label:
Eosinophils percent (%)
English Text:
Eosinophils percent (%)
Target:
Both males and females 1 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0.1 to 32.9 Range of Values 8378 8378
. Missing 1062 9440

LBXBAPCT - Basophils percent (%)

Variable Name:
LBXBAPCT
SAS Label:
Basophils percent (%)
English Text:
Basophils percent (%)
Target:
Both males and females 1 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0 to 15.8 Range of Values 8378 8378
. Missing 1062 9440

LBDLYMNO - Lymphocyte number (1000 cells/uL)

Variable Name:
LBDLYMNO
SAS Label:
Lymphocyte number (1000 cells/uL)
English Text:
Lymphocyte number (1000 cells/uL)
Target:
Both males and females 1 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0.4 to 48.4 Range of Values 8378 8378
. Missing 1062 9440

LBDMONO - Monocyte number (1000 cells/uL)

Variable Name:
LBDMONO
SAS Label:
Monocyte number (1000 cells/uL)
English Text:
Monocyte number (1000 cells/uL)
Target:
Both males and females 1 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0 to 3.2 Range of Values 8378 8378
. Missing 1062 9440

LBDNENO - Segmented neutrophils num (1000 cell/uL)

Variable Name:
LBDNENO
SAS Label:
Segmented neutrophils num (1000 cell/uL)
English Text:
Segmented neutrophils num (1000 cell/uL)
Target:
Both males and females 1 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0.5 to 17.8 Range of Values 8378 8378
. Missing 1062 9440

LBDEONO - Eosinophils number (1000 cells/uL)

Variable Name:
LBDEONO
SAS Label:
Eosinophils number (1000 cells/uL)
English Text:
Eosinophils number (1000 cells/uL)
Target:
Both males and females 1 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0 to 3.8 Range of Values 8378 8378
. Missing 1062 9440

LBDBANO - Basophils number (1000 cells/uL)

Variable Name:
LBDBANO
SAS Label:
Basophils number (1000 cells/uL)
English Text:
Basophils number (1000 cells/uL)
Target:
Both males and females 1 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0 to 1.4 Range of Values 8378 8378
. Missing 1062 9440

LBXRBCSI - Red blood cell count (million cells/uL)

Variable Name:
LBXRBCSI
SAS Label:
Red blood cell count (million cells/uL)
English Text:
Red blood cell count (million cells/uL)
Target:
Both males and females 1 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
2.44 to 7.08 Range of Values 8400 8400
. Missing 1040 9440

LBXHGB - Hemoglobin (g/dL)

Variable Name:
LBXHGB
SAS Label:
Hemoglobin (g/dL)
English Text:
Hemoglobin (g/dL)
Target:
Both males and females 1 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
5.8 to 19.3 Range of Values 8400 8400
. Missing 1040 9440

LBXHCT - Hematocrit (%)

Variable Name:
LBXHCT
SAS Label:
Hematocrit (%)
English Text:
Hematocrit (%)
Target:
Both males and females 1 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
19.7 to 55.5 Range of Values 8400 8400
. Missing 1040 9440

LBXMCVSI - Mean cell volume (fL)

Variable Name:
LBXMCVSI
SAS Label:
Mean cell volume (fL)
English Text:
Mean cell volume (fL)
Target:
Both males and females 1 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
51.1 to 121.9 Range of Values 8400 8400
. Missing 1040 9440

LBXMCHSI - Mean cell hemoglobin (pg)

Variable Name:
LBXMCHSI
SAS Label:
Mean cell hemoglobin (pg)
English Text:
Mean cell hemoglobin (pg)
Target:
Both males and females 1 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
14.7 to 42.8 Range of Values 8400 8400
. Missing 1040 9440

LBXMC - MCHC (g/dL)

Variable Name:
LBXMC
SAS Label:
MCHC (g/dL)
English Text:
Mean cell hemoglobin concentration (g/dL)
Target:
Both males and females 1 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
28.8 to 39.5 Range of Values 8400 8400
. Missing 1040 9440

LBXRDW - Red cell distribution width (%)

Variable Name:
LBXRDW
SAS Label:
Red cell distribution width (%)
English Text:
Red cell distribution width (%)
Target:
Both males and females 1 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
10.7 to 26.5 Range of Values 8400 8400
. Missing 1040 9440

LBXPLTSI - Platelet count SI (1000 cells/uL)

Variable Name:
LBXPLTSI
SAS Label:
Platelet count SI (1000 cells/uL)
English Text:
Platelet count SI (1000 cells/uL)
Target:
Both males and females 1 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
4 to 1000 Range of Values 8400 8400
. Missing 1040 9440

LBXMPSI - Mean platelet volume (fL)

Variable Name:
LBXMPSI
SAS Label:
Mean platelet volume (fL)
English Text:
Mean platelet volume (fL)
Target:
Both males and females 1 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
5 to 12.4 Range of Values 8400 8400
. Missing 1040 9440