Table of Contents

Component Description

The complete blood count (CBC) with 5-part differential counts red blood cells (RBCs), white blood cells (WBCs) and platelets; measures hemoglobin; estimates the red cells’ volume and sorts the WBCs into subtypes. A CBC is a routine blood test used to evaluate your overall health and detect a wide range of disorders, including anemia, infection, and leukemia.

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

Examined participants aged 1 year and over were eligible.

Description of Laboratory Methodology

Refer to the Laboratory Method Files section for a detailed description of the laboratory methods used.

There were no changes to the lab method, lab equipment, or lab site for this component in the NHANES 2015-2016 cycle.

Laboratory Method Files

Laboratory Quality Assurance and Monitoring

Whole blood samples are analyzed on the NHANES MEC.

Detailed instructions on specimen collection and processing are discussed in the NHANES Laboratory Procedures Manual (LPM).

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

Mobile Examination Centers (MECs)

Laboratory team performance is monitored using several techniques. NCHS and contract consultants use a structured competency assessment evaluation during visits to evaluate both the quality of the laboratory work and the quality-control procedures. Each laboratory staff member is observed for equipment operation, specimen collection and preparation; testing procedures and constructive feedback are given to each staff member. Formal retraining sessions are conducted annually to ensure that required skill levels were maintained.

Analytical Laboratories

NHANES uses several methods to monitor the quality of the analyses performed by the NHANES laboratories. In the MEC, the CBC results are measured in duplicate and averaged. The averaged results are reported to participant and released in this dataset.

NCHS developed and distributed a quality control protocol for all CDC and contract laboratories, which outlined the use of Westgard rules (Westgard, et al. 1981) when running NHANES specimens. Progress reports containing any problems encountered during the analysis of the specimens, summary statistics for each control pool, QC graphs, instrument calibration, reagents, and any special considerations are submitted to NCHS quarterly. The reports are reviewed for trends or shifts in the data.

All QC procedures recommended by the manufacturers were followed. Reported results for all assays meet NHANES quality control and quality assurance performance criteria for accuracy and precision, similar to the Westgard rules.

Data Processing and Editing

The data were reviewed. Incomplete data or improbable values were sent to the performing laboratory for confirmation.

Five derived variables were created in this data file. The variables were created using the following formulas:

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)

Analytic Notes

Refer to the 2015-2016 Laboratory Data Overview for general information on NHANES laboratory data.

Demographic and Other Related Variables

The analysis of NHANES 2015-2016 laboratory data must be conducted using the appropriate survey design and demographic variables. The NHANES 2015-2016 Demographics File contains demographic data, health indicators, and other related information collected during household interviews as well as the sample design variables. The recommended procedure for variance estimation requires use of stratum and PSU variables (SDMVSTRA and SDMVPSU, respectively) in the demographic file.

The Fasting Questionnaire File includes auxiliary information, such as fasting status, the length of fast and the time of venipuncture.

The detection limits were constant for all of the analytes in the data set. None of the results were below the limits of detection.This laboratory data file can be linked to the other NHANES data files using the unique survey participant identifier (i.e., SEQN).

Detection Limits

Variable Name

SAS Label

LLOD

ULOD

Range

LBXWBCSI

White blood cell count

0.050

400.000

x 103 cells/uL

LBXLYPCT

Lymphocyte percent

0.00

100.00

%

LBXMOPCT

Monocyte percent

0.00

100.00

%

LBXNEPCT

Segmented neutrophils percent

0.00

100.00

%

LBXEOPCT

Eosinophils percent

0.00

100.00

%

LBXBAPCT

Basophils percent

0.00

100.00

%

LBXRBCSI

Red blood cell count

0.005

8.5

x 106 cells/uL

LBXHGB

Hemoglobin

0.10

25.50

g/dL

LBXMCVSI

Mean cell volume

50.00

150.00

fL

LBXRDW

Red cell distribution width

10.00

40.00

%

LBXPLTSI

Platelet count

3.0

3000.0

x 103 cells/uL

LBXMPSI

Mean platelet volume

5.00

25.00

fL

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.

 


References

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
1.4 to 117.2 Range of Values 8117 8117
. Missing 1048 9165

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
3.7 to 94.5 Range of Values 8116 8116
. Missing 1049 9165

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
1.4 to 29.3 Range of Values 8116 8116
. Missing 1049 9165

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
3.6 to 93.2 Range of Values 8116 8116
. Missing 1049 9165

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 to 32.2 Range of Values 8116 8116
. Missing 1049 9165

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
0.1 to 4 Range of Values 8116 8116
. Missing 1049 9165

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
0.2 to 110.8 Range of Values 8116 8116
. Missing 1049 9165

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
0.1 to 2.6 Range of Values 8116 8116
. Missing 1049 9165

LBDNENO - Segmented neutrophils num (1000 cell/uL)

Variable Name:
LBDNENO
SAS Label:
Segmented neutrophils num (1000 cell/uL)
English Text:
Segmented neutrophils number (1000 cell/uL)
Target:
Both males and females 1 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0.3 to 19.4 Range of Values 8116 8116
. Missing 1049 9165

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 4.5 Range of Values 8116 8116
. Missing 1049 9165

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 0.3 Range of Values 8116 8116
. Missing 1049 9165

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
2.52 to 7.9 Range of Values 8117 8117
. Missing 1048 9165

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
6.2 to 19.2 Range of Values 8117 8117
. Missing 1048 9165

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
21.8 to 59.1 Range of Values 8117 8117
. Missing 1048 9165

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
50.8 to 115.6 Range of Values 8117 8117
. Missing 1048 9165

LBXMCHSI - Mean Cell Hgb Conc. (g/dL)

Variable Name:
LBXMCHSI
SAS Label:
Mean Cell Hgb Conc. (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
13.8 to 38.5 Range of Values 8117 8117
. Missing 1048 9165

LBXMCH - Mean cell hemoglobin (pg)

Variable Name:
LBXMCH
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
. Missing 9165 9165

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
11.5 to 26.4 Range of Values 8117 8117
. Missing 1048 9165

LBXPLTSI - Platelet count (1000 cells/uL)

Variable Name:
LBXPLTSI
SAS Label:
Platelet count (1000 cells/uL)
English Text:
Platelet count (1000 cells/uL)
Target:
Both males and females 1 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
14 to 777 Range of Values 8117 8117
. Missing 1048 9165

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
5.6 to 15.1 Range of Values 8117 8117
. Missing 1048 9165