Table of Contents

Locator Record

Title: Body Measurements (BMX_B )
Contact Number: 1-866-441-NCHS
Years of Content: 2001 - 2002
First Published: May, 2004
Revised: NA
Access Constraints: None
Use Constraints: None
Geographic Coverage: National
Subject:Body Measurements
Record Source: NHANES 2001 - 2002
Survey Methodology: NHANES 2001 - 2002 is a stratified multistage probability sample of the civilian non-institutionalized population of the U.S.
Medium: NHANES Web site; SAS transport files

Component Description

The purpose of this component is to collect high quality body measurement data on survey participants. The NHANES body measurement component procedures are outlined in the NHANES Anthropometry Procedures Manual which is posted on the NHANES website (URL: http://www.cdc.gov/nchs/data/nhanes/bm.pdf).

The body measurement assessments performed on survey participants varied according to the age of the survey participant. The body measurement protocol used age at the time of the screening interview. In some instances, several weeks elapsed between the initial screening interview and the health examination visit. The Demographics Data File includes an age variable for age at examination. The target samples for the body measurement assessments are as follows:

Body weight: All ages
Recumbent length: 0 through 47 months
Standing height: 24+ months
Upper leg length: 8+ years
Upper arm length: 2+ months
Head circumference: 0 through 5 months
Mid-upper arm circumference: 2+ months
Waist circumference: 24+ months
Mid-thigh circumference: 8+ years
Maximal calf circumference: 8+ years
Triceps skin fold: 2+ months
Sub scapular skin fold: 2+months

Occasionally circumstances arose when it was not possible to complete the component on participants due to lack of time. At a minimum, weight and standing height or recumbent length were measured.

Eligible Sample

There were no medical, safety, or other exclusions for the body measurements protocol. For persons who used a wheelchair, the health technicians used their discretion to obtain as many measures as practical. Height and weight were not typically measured in persons who used wheelchairs.

Arm and leg measurements were made on the right side of the body. If an examinee had an amputation, medical condition, or medical appliance such as a cast that prevented measurements from being taken on the right side of the body, the examiner took measurements on the left side. The body measurements file does not identify persons with amputations due to data disclosure concerns. Body weight data for individuals who had limb amputations were excluded from the release file. A small number of measurements could not be obtained because of physical problems such as spine deformities, measures that exceeded the capacity of the measuring device, or when objects such as clothing (e.g., if a subject refused to change into an examination gown, remove their shoes, etc.) or hair decorations made it impossible to obtain accurate measurements.

This data set includes body measurements for women who were pregnant at the time of the exam. Analysts should determine if it is appropriate to exclude data for pregnant women in a particular analysis. Pregnancy status information is denoted by the Demographic Data File variable, RIDPREG.

Protocol and Procedure

The data collection methods, examination protocol, and data collection forms are fully documented in the NHANES Anthropometry Procedures Manual. In addition, for general guidelines on standard procedures that were followed for the anthropometric measures, please refer to the Anthropometric Standardization Reference Manual (Lohman, 1988). The actual measurement techniques used in the survey are illustrated in the NHANES III Anthropometric Procedures Video. The video demonstrates the NHANES III anthropometric procedures in detail, and illustrates all of the measures except the calf circumference. This video may be obtained from the U.S. Government Printing Office (http://www.cdc.gov/nchs/about/major/nhanes/avideo.htm). Please note that some of the measurements that were taken in NHANES III are not included in the protocol for the current survey.

All body measures were obtained by trained health technicians. The body measurement component was performed in a specially equipped room in the mobile examination center (MEC). The health technician was assisted by a trained recorder. The technician and recorders worked as a team to position, measure, and record the body measurement data accurately.

Quality Assurance & Quality Control

The first line of quality control was provided by the automated data collection system. For weight, standing height, and recumbent length, all data were captured electronically from the measuring instruments to minimize potential data entry errors. Range edits, based on the 1st and 99th percentiles of the NHANES III distributions for age and gender categories were programmed into the automated data collection system. The data entry system generated messages that prompted the health technicians to verify or re-check measures that were outside the 1st and 99th percentile limits for a particular measurement.

Experienced trainers, NCHS staff, contractor staff, and gold standard examiners monitored health technician performance in the field. Retraining sessions were conducted with the technicians periodically and annually to reinforce the proper protocols and technique. Replicate examinations were performed by the gold standard examiners during visits to the field. Routine calibration of the body measures equipment was a part of the quality control plan for this component. The NHANES Anthropometry Procedures Manual details the equipment calibration procedures.

Data Processing and Editing

The data recorded in the MEC were not modified during file preparation.

The data were edited for values that exceeded the capacity of the measuring equipment. Biologically implausible values were identified by examining age and sex-specific measurements that exceeded the 1st and 99th percentile values of the NHANES III distributions for each measure. A small number of observations that were implausible were set to missing.

Analytic Notes

During the data editing process, outlier values were examined. When there was insufficient information to conclude that values were invalid, they were left in the data set. Analysts should examine the data spread and consider whether or not it is appropriate to include or exclude extreme values in a given analysis.

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 0 YEARS - 150 YEARS

BMXWT - Weight (kg)

Variable Name:
BMXWT
SAS Label:
Weight (kg)
English Text:
Weight (kg)
Target:
Both males and females 0 YEARS - 150 YEARS
Hard Edits:
0.0000 to 440.0000
Code or Value Value Description Count Cumulative Skip to Item
3.3 to 196.8 Range of Values 9825 9825
. Missing 652 10477

BMIWT - Weight Comment

Variable Name:
BMIWT
SAS Label:
Weight Comment
English Text:
Weight Comment
Target:
Both males and females 0 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
1 Could not obtain 35 35
2 Exceeds capacity 0 35
3 Clothing 531 566
4 Medical appliance 21 587
. Missing 9890 10477

BMXRECUM - Recumbent Length (cm)

Variable Name:
BMXRECUM
SAS Label:
Recumbent Length (cm)
English Text:
Recumbent Length (cm)
Target:
Both males and females 0 MONTHS - 47 MONTHS
Hard Edits:
16.0000 to 119.3000
Code or Value Value Description Count Cumulative Skip to Item
48.4 to 112.7 Range of Values 1352 1352
. Missing 9125 10477

BMIRECUM - Recumbent Length Comment

Variable Name:
BMIRECUM
SAS Label:
Recumbent Length Comment
English Text:
Recumbent Length Comment
Target:
Both males and females 0 MONTHS - 47 MONTHS
Code or Value Value Description Count Cumulative Skip to Item
1 Could not obtain 73 73
2 Exceeds capacity 0 73
3 Not straight 1 74
. Missing 10403 10477

BMXHEAD - Head Circumference (cm)

Variable Name:
BMXHEAD
SAS Label:
Head Circumference (cm)
English Text:
Head Circumference (cm)
Target:
Both males and females 0 MONTHS - 6 MONTHS
Hard Edits:
00.0000 to 99.9999
Code or Value Value Description Count Cumulative Skip to Item
35.1 to 50.2 Range of Values 296 296
. Missing 10181 10477

BMIHEAD - Head Circumference Comment

Variable Name:
BMIHEAD
SAS Label:
Head Circumference Comment
English Text:
Head Circumference Comment
Target:
Both males and females 0 MONTHS - 6 MONTHS
Code or Value Value Description Count Cumulative Skip to Item
1 Could not obtain 3 3
2 Exceeds capacity 0 3
3 Not straight 0 3
. Missing 10474 10477

BMXHT - Standing Height (cm)

Variable Name:
BMXHT
SAS Label:
Standing Height (cm)
English Text:
Standing Height (cm)
Target:
Both males and females 2 YEARS - 150 YEARS
Hard Edits:
79.0000 to 208.4000
Code or Value Value Description Count Cumulative Skip to Item
79 to 199.1 Range of Values 9363 9363
. Missing 1114 10477

BMIHT - Standing Height Comment

Variable Name:
BMIHT
SAS Label:
Standing Height Comment
English Text:
Standing Height Comment
Target:
Both males and females 2 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
1 Could not obtain 74 74
2 Exceeds capacity 0 74
3 Not straight 96 170
. Missing 10307 10477

BMXBMI - Body Mass Index (kg/m**2)

Variable Name:
BMXBMI
SAS Label:
Body Mass Index (kg/m**2)
English Text:
Body Mass Index (kg/m**2)
Target:
Both males and females 2 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
7.99 to 65.41 Range of Values 9010 9010
. Missing 1467 10477

BMXLEG - Upper Leg Length (cm)

Variable Name:
BMXLEG
SAS Label:
Upper Leg Length (cm)
English Text:
Upper Leg Length (cm)
Target:
Both males and females 8 YEARS - 150 YEARS
Hard Edits:
0.0000 to 200.0000
Code or Value Value Description Count Cumulative Skip to Item
24.8 to 55 Range of Values 7846 7846
. Missing 2631 10477

BMILEG - Upper Leg Length Comment

Variable Name:
BMILEG
SAS Label:
Upper Leg Length Comment
English Text:
Upper Leg Length Comment
Target:
Both males and females 8 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
1 Could not obtain 336 336
. Missing 10141 10477

BMXCALF - Maximal Calf Circumference (cm)

Variable Name:
BMXCALF
SAS Label:
Maximal Calf Circumference (cm)
English Text:
Maximal Calf Circumference (cm)
Target:
Both males and females 8 YEARS - 150 YEARS
Hard Edits:
0.0000 to 200.0000
Code or Value Value Description Count Cumulative Skip to Item
21.6 to 61.6 Range of Values 7933 7933
. Missing 2544 10477

BMICALF - Maximal Calf Comment

Variable Name:
BMICALF
SAS Label:
Maximal Calf Comment
English Text:
Maximal Calf Comment
Target:
Both males and females 8 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
1 Could not obtain 254 254
. Missing 10223 10477

BMXARML - Upper Arm Length (cm)

Variable Name:
BMXARML
SAS Label:
Upper Arm Length (cm)
English Text:
Upper Arm Length (cm)
Target:
Both males and females 2 MONTHS - 150 YEARS
Hard Edits:
0.0000 to 200.0000
Code or Value Value Description Count Cumulative Skip to Item
10 to 46.5 Range of Values 9869 9869
. Missing 608 10477

BMIARML - Upper Arm Length Comment

Variable Name:
BMIARML
SAS Label:
Upper Arm Length Comment
English Text:
Upper Arm Length Comment
Target:
Both males and females 2 MONTHS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
1 Could not obtain 460 460
. Missing 10017 10477

BMXARMC - Arm Circumference (cm)

Variable Name:
BMXARMC
SAS Label:
Arm Circumference (cm)
English Text:
Arm Circumference (cm)
Target:
Both males and females 2 MONTHS - 150 YEARS
Hard Edits:
0.0000 to 200.0000
Code or Value Value Description Count Cumulative Skip to Item
11.1 to 59.8 Range of Values 9868 9868
. Missing 609 10477

BMIARMC - Arm Circumference Comment

Variable Name:
BMIARMC
SAS Label:
Arm Circumference Comment
English Text:
Arm Circumference Comment
Target:
Both males and females 2 MONTHS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
1 Could not obtain 461 461
. Missing 10016 10477

BMXWAIST - Waist Circumference (cm)

Variable Name:
BMXWAIST
SAS Label:
Waist Circumference (cm)
English Text:
Waist Circumference (cm)
Target:
Both males and females 2 YEARS - 150 YEARS
Hard Edits:
0.0000 to 200.0000
Code or Value Value Description Count Cumulative Skip to Item
39.6 to 165.2 Range of Values 9056 9056
. Missing 1421 10477

BMIWAIST - Waist Circumference Comment

Variable Name:
BMIWAIST
SAS Label:
Waist Circumference Comment
English Text:
Waist Circumference Comment
Target:
Both males and females 2 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
1 Could not obtain 467 467
. Missing 10010 10477

BMXTHICR - Thigh Circumference (cm)

Variable Name:
BMXTHICR
SAS Label:
Thigh Circumference (cm)
English Text:
Thigh Circumference (cm)
Target:
Both males and females 8 YEARS - 150 YEARS
Hard Edits:
0.0000 to 200.0000
Code or Value Value Description Count Cumulative Skip to Item
29.2 to 100 Range of Values 7804 7804
. Missing 2673 10477

BMITHICR - Thigh Circumference Comment

Variable Name:
BMITHICR
SAS Label:
Thigh Circumference Comment
English Text:
Thigh Circumference Comment
Target:
Both males and females 8 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
1 Could not obtain 378 378
. Missing 10099 10477

BMXTRI - Triceps Skinfold (mm)

Variable Name:
BMXTRI
SAS Label:
Triceps Skinfold (mm)
English Text:
Triceps Skinfold (mm)
Target:
Both males and females 2 MONTHS - 150 YEARS
Hard Edits:
0.0000 to 45.0000
Code or Value Value Description Count Cumulative Skip to Item
1.4 to 44.7 Range of Values 9432 9432
. Missing 1045 10477

BMITRI - Triceps Skinfold Comment

Variable Name:
BMITRI
SAS Label:
Triceps Skinfold Comment
English Text:
Triceps Skinfold Comment
Target:
Both males and females 2 MONTHS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
1 Could not obtain 640 640
2 Exceeds capacity 255 895
3 Hard to obtain 0 895
. Missing 9582 10477

BMXSUB - Subscapular Skinfold (mm)

Variable Name:
BMXSUB
SAS Label:
Subscapular Skinfold (mm)
English Text:
Subscapular Skinfold (mm)
Target:
Both males and females 2 MONTHS - 150 YEARS
Hard Edits:
0.0000 to 45.0000
Code or Value Value Description Count Cumulative Skip to Item
2.8 to 43.2 Range of Values 8553 8553
. Missing 1924 10477

BMISUB - Subscapular Skinfold Comment

Variable Name:
BMISUB
SAS Label:
Subscapular Skinfold Comment
English Text:
Subscapular Skinfold Comment
Target:
Both males and females 2 MONTHS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
1 Could not obtain 1666 1666
2 Exceeds capacity 111 1777
3 Hard to obtain 0 1777
. Missing 8700 10477