BODY MEASUREMENTS Body measurements were recorded for all examinees by a trained examiner in the mobile examination center (MEC). The protocol for this component did not detail any medical, safety or other exclusions. The body measurements examination included measures of weight, standing height, lengths, skinfolds, circumferences, and breadths. In cases when examinees had to leave the MEC early and were unable to participate in the complete body measures component, at a minimum, weight and standing height or recumbent length were measured. Persons aged under one year or 20 years and over who were examined only in their homes were given a subset of the body measures. These measures were taken by trained technicians who used equipment and procedures comparable to those used in the mobile examination centers. Therefore, the home examination body measures were incorporated into the body measures data set. To determine which subjects were home examinees, the DMPSTAT variable (3=home-examined) should be used. When analyzing data for combined home-examined and MEC-examined subjects, the combined MEC- plus home-examined sample weights should be used (WTPFHX6). When using only MEC items or measures, the MEC examination sample weight should be used (WTPFEX6). For more information on the use of sample weights in the NHANES III data analysis, refer to the Analytic and Reporting Guidelines (U.S. DHHS, 1996b). The following are the names shown on the Home Examination form in the Plan and Operation of the Third National Health and Nutrition Examination Survey, 1988-1994 (original home exam variable name; new name) for home examination body measures (NCHS, 1994, p. 313; U.S. DHHS, 1996b). In the home exam, the only body measures taken were weight (A1; BMPWT), standing height (A2; BMPHT), arm circumference (A6; BMPARMCI), and triceps skinfold (A5; BMPTRI). For infants aged less than one year, recumbent length (A3; BMPRECUM) was measured instead of stature, and head circumference (A4; BMPHEAD) was added. For examinees who received only a home examination, the measures listed above are the only body measures available for analysis. Values for all other body measures for these examinees appear as blank. Bioelectrical impedance analysis (BIA) data are considered a part of body measurements and have been included with the body measurement data. However, the BIA resistance and reactance measures were recorded by the physicians in the physician's examination component, hence the "PEP" variable prefix. For general guidelines on standard procedures that were followed for the anthropometric measures, refer to The Anthropometric Standardization Reference Manual (Lohman, 1988). For specific guidelines, the Anthropometric Procedures Video that demonstrates the NHANES III anthropometric procedures in detail is available from the U.S. Government Printing Office (U.S. DHHS, 1996a). The MEC health technicians, ultrasonographers, dentists, and home examination health technicians were trained by two trainers to do the anthropometric measurements. The two trainers were cross-standardized initially and then annually during the survey. Group retraining occurred twice during the survey. Periodic visits to the field by each of the trainers assured ongoing quality control in the accuracy and reliability of the procedures. This data set includes body measurements for women who were pregnant at the time of the exam. Analysts should determine whether it is appropriate to exclude data for these women for a given analysis. Pregnancy status information is found in the variable MAPF12R in the MEC Adult Questionnaire and in the variable MYPC17 in the MEC Youth Questionnaire. During the editing process, outliers were scrutinized using univariate and multivariate methods to help identify implausible values. 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 it is appropriate to include or exclude extreme values in a given analysis. Data processing and editing were performed to ensure internal data consistency. Notes have been provided for variables requiring additional explanation. NHANES III Examination Data File ------------------------------------------------------------------------ BODY MEASUREMENTS ------------------------------------------------------------------------ GENERAL INFORMATION ------------------------------------------------------------------------ Positions Item description SAS name Counts and code Notes ------------------------------------------------------------------------ 1503-1507 Examiner number BMPTECH1 30426 01001-09018 392 88888 Blank but applicable 493 Blank NHANES III Examination Data File ------------------------------------------------------------------------ BODY MEASUREMENTS ------------------------------------------------------------------------ WEIGHT ------------------------------------------------------------------------ Positions Item description SAS name Counts and code Notes ------------------------------------------------------------------------ 1508-1513 Weight (kg) BMPWT (2 months and over) 31132 0002.8-0241.8 179 888888 Blank but applicable 1514 Weight source flag See note BMPWTFLG 30324 0 No substitution 667 3 Modeled from reported value 320 4 Reported value 1515-1519 Weight (lbs) See note BMPWTLBS (2 months and over) 31132 006.2-00532 179 88888 Blank but applicable 1520-1523 Self-reported weight (lbs) See note BMPSRWL (12-16 years) 1673 0078-0350 406 8888 Blank but applicable 29232 Blank 1524-1527 Body mass index See note BMPBMI 27830 07.3-79.6 227 8888 Blank but applicable 3254 Blank NHANES III Examination Data File ------------------------------------------------------------------------ BODY MEASUREMENTS ------------------------------------------------------------------------ HEIGHTS, LENGTHS ------------------------------------------------------------------------ Positions Item description SAS name Counts and code Notes ------------------------------------------------------------------------ 1528-1532 Standing height (cm) BMPHT (2 years and over) 27935 073.6-206.5 122 88888 Blank but applicable 3254 Blank 1533 Standing height source flag See note BMPHTFLG 27514 0 No substitution 226 1 Modeled from spirometry height 66 2 Spirometry height 241 3 Modeled from reported value 10 5 Recumbent length 3254 Blank 1534-1538 Standing height (in) See note BMPHTIN (2 years and over) 27935 00029-081.3 122 88888 Blank but applicable 3254 Blank 1539-1543 Recumbent length (cm) BMPRECUM (2 months-3 years) 5525 039.1-119.5 118 88888 Blank but applicable 25668 Blank 1544 Recumbent length flag See note BMPRECFL 5466 0 No substitution 42 3 Modeled from reported value 135 6 Stature 25668 Blank 1545-1549 Sitting height (cm) BMPSITHT (2 years and over) 27009 036.9-110.2 590 88888 Blank but applicable 3712 Blank NHANES III Examination Data File ------------------------------------------------------------------------ BODY MEASUREMENTS ------------------------------------------------------------------------ HEIGHTS, LENGTHS ------------------------------------------------------------------------ Positions Item description SAS name Counts and code Notes ------------------------------------------------------------------------ 1550-1552 Self-reported height (in) See note BMPSRHIS (12-16 years) 1957 036-091 122 888 Blank but applicable 29232 Blank 1553-1556 Upper leg length (cm) BMPLEG (2 years and over) 26313 12.9-58.1 1286 8888 Blank but applicable 3712 Blank 1557-1560 Knee height (cm) BMPKNEE (60 years and over) 4938 0032-63.3 364 8888 Blank but applicable 26009 Blank 1561-1564 Upper arm length (cm) BMPARML (2 months and over) 29606 06.2-64.8 1212 8888 Blank but applicable 493 Blank NHANES III Examination Data File ------------------------------------------------------------------------ BODY MEASUREMENTS ------------------------------------------------------------------------ BREADTHS ------------------------------------------------------------------------ Positions Item description SAS name Counts and code Notes ------------------------------------------------------------------------ 1565-1568 Biacromial breadth (cm) BMPBIAC (3 years and over) 25357 15.3-58.3 973 8888 Blank but applicable 4981 Blank 1569-1573 Biiliac breadth (cm) BMPBIIL (2 years and over) 26352 009.8-048.7 1247 88888 Blank but applicable 3712 Blank 1574-1577 Elbow breadth (cm) BMPELB (2 years and over) 26541 0003-10.4 1058 8888 Blank but applicable 3712 Blank 1578-1581 Wrist breadth (cm) BMPWRIST (2 years and over) 26536 02.7-08.3 1063 8888 Blank but applicable 3712 Blank NHANES III Examination Data File ------------------------------------------------------------------------ BODY MEASUREMENTS ------------------------------------------------------------------------ CIRCUMFERENCES ------------------------------------------------------------------------ Positions Item description SAS name Counts and code Notes ------------------------------------------------------------------------ 1582-1585 Head circumference (cm) BMPHEAD (2 months-7 years) 8609 34.4-58.1 259 8888 Blank but applicable 22443 Blank 1586-1589 Arm circumference (cm) BMPARMC (2 months and over) 30020 0009-61.2 1291 8888 Blank but applicable 1590-1594 Waist circumference (cm) BMPWAIST (2 years and over) 26288 034.5-174.1 1311 88888 Blank but applicable 3712 Blank 1595-1599 Buttocks circumference (cm) BMPBUTTO (2 years and over) 26290 027.8-179.2 1309 88888 Blank but applicable 3712 Blank 1600-1603 Waist-to-hip ratio See note BMPWHR 26236 0.51-2.09 1363 8888 Blank but applicable 3712 Blank 1604-1608 Thigh circumference (cm) BMPTHICI (2 years and over) 26188 00016-093.8 1411 88888 Blank but applicable 3712 Blank NHANES III Examination Data File ------------------------------------------------------------------------ BODY MEASUREMENTS ------------------------------------------------------------------------ SKINFOLDS ------------------------------------------------------------------------ Positions Item description SAS name Counts and code Notes ------------------------------------------------------------------------ 1609-1612 Triceps skinfold (mm) See note BMPTRI (2 months and over) 29571 01.9-48.5 311 5555 Skinfold too large for caliper 1429 8888 Blank but applicable 1613-1616 Subscapular skinfold (mm) See note BMPSUB (2 months and over) 28502 02.8-0049 397 5555 Skinfold too large for caliper 1919 8888 Blank but applicable 493 Blank 1617-1620 Suprailiac skinfold (mm) See note BMPSUP (2 years and over) 25487 02.3-49.4 636 5555 Skinfold too large for caliper 1476 8888 Blank but applicable 3712 Blank 1621-1624 Thigh skinfold (mm) See note BMPTHI (2 years and over) 23814 02.2-49.5 1574 5555 Skinfold too large for caliper 2211 8888 Blank but applicable 3712 Blank NHANES III Examination Data File ------------------------------------------------------------------------ BODY MEASUREMENTS ------------------------------------------------------------------------ BIOELECTRICAL IMPEDANCE ANALYSIS (BIA) ------------------------------------------------------------------------ Positions Item description SAS name Counts and code Notes ------------------------------------------------------------------------ 1625 Examinee pregnant--cannot obtain BIA See note PEPPREG 197 1 Yes 17840 2 No 1662 8 Blank but applicable 85 9 Don't know 11527 Blank 1626 Examinee had pacemaker--cannot See note PEPPACE obtain BIA 41 1 Yes 17996 2 No 1738 8 Blank but applicable 9 9 Don't know 11527 Blank 1627-1630 BIA resistance (ohms) See note PEP12A1 (12 years and over) 17726 0269-0950 1820 8888 Blank but applicable 11765 Blank 1631-1634 BIA reactance (ohms) See note PEP12B1 (12 years and over) 17712 0013-0135 1834 8888 Blank but applicable 11765 Blank NOTES BMPBMI: Body mass index BMPBMI was computed from weight and standing height using the following formula: BMPBMI=BMPWT/((BMPHT/100)**2). BMPHTFLG, BMPRECFL, BMPWTFLG: Standing height, recumbent length, and weight source flags Weight, standing height, and recumbent length are fundamental body measures essential to most analyses of other health examination data. Therefore, during data editing, a special procedure was established and followed only for those three variables when the primary measures were missing. This procedure allowed available alternate source data to be substituted for missing primary source data. In selected cases, when data were absent from the primary health examination, the source of the substitution is indicated by a derived indicator (flag) variable (i.e., BMPWTFLG, BMPHTFLG, BMPRECFL). These substitutions were derived from tests on the actual data and evaluated and selected using cross- validations on the actual data; they yielded satisfactory results with R-squared values and correlations. The flag values range from 00 to 06, and corresponding interpretations of these flag codes have been summarized as follows: 00 No substitution 01 Modeled from spirometry height (i.e., standing height measured in the spirometry exam) 02 Direct substitution for standing height from spirometry standing height 03 Modeled from interview reported value 04 Direct substitution for weight from reported weight 05 Direct substitution for standing height from measured recumbent length 06 Direct substitution for recumbent length from measured standing height The approach to obtain substitutions for "Blank but applicable" (8-filled) primary recumbent length, standing height, and weight, ranked in order of data availability, included: Recumbent length (age 2-47 months) Direct substitution from stature, if present, into recumbent length (age 2-3 years)(code 06). If no substitution was possible from stature, a sex-specific model with reported length, race/ethnicity, age (mo), education of adult reference person, and reported weight was used (code 03). Height (age 2-16 years) Direct substitution from recumbent length (age 2-3 years) (code 05). Direct substitution from spirometry height (age 8-16 years) (code 02) If spirometry height was not available, a sex- and year-of-age-specific model with reported height, race/ethnicity, age (mo), education of adult reference person, and reported weight was used (code 03). Height (age 17 years and over) A sex-specific model with spirometry height, reported height, race/ethnicity, age (mo), and reported weight was used (code 01). If spirometry height was not available, a sex-specific model with reported height, race/ethnicity, and age (mo) was used (code 03). Weight (age 2-23 months) A sex- and year-of-age-specific model with reported weight, race/ethnicity, age (mo), education of adult reference person, and measured recumbent length was used (code 03). Weight (age 2-11 years) Sex- and year-of-age-specific model with reported weight, race/ethnicity, age (mo), education of adult reference person, and measured standing height was used (Code 03). Weight (age 12-16 years) Sex- and year-of-age-specific model with reported weight, race/ethnicity, and measured stature was used (code 03). Weight (age 17 years and over) A sex-specific model with reported weight, reported weight from bone density screener questionnaire, measured height, race/ethnicity, and age (yr) was used (code 03). If the above variables were not present, direct substitution from reported weight was used (code 04). BMPHTIN: Standing height (in) BMPHTIN is standing height converted to inches from centimeters and was calculated as BMPHTIN=BMPHT/2.54. BMPRECFL: Recumbent length source flag See note for BMPHTFLG. BMPSRHIS and BMPSRWL: Self-reported height (in) and weight (lbs) BMPSRHIS is a derived variable that converts reported height in feet and inches to total inches. It is equal to the reported height in feet multiplied by 12 plus the reported height in inches. All NHANES III participants were asked to report their current height in feet and inches and their weight in pounds. Reported height (BMPSRHIS) and weight (BMPSRWL) information was obtained from adolescents (aged 12 through 16 years) during the body measures component just prior to the actual measurement of weight (BMPWT) and height (BMPHT). For examinees of all other ages, data for similar reported values can be found in the Household Adult Questionnaire among persons aged over 17 years for height (HAM5S) and weight (HAM6S) and in the Household Youth Questionnaire among persons aged less than 12 years for height (HYB18S) and weight (HYB19S). Note that in the data editing process some unusual values for reported height were observed. For persons aged 12 through 16 years, values less than 3 feet were deleted and recoded as "Blank but applicable" (8888). BMPSRWL: Self-reported weight (lbs) See note for BMPSRHIS. BMPSUB, BMPSUP, BMPTHI, BMPTRI: Skinfolds For NHANES III, the body measurements protocol specified that skinfolds would be measured at four different anatomic body sites. Independent measures were taken at each body site by two technicians, resulting in a minimum of two skinfold observations for each site. If the difference between the two measurements at a given site was within a pre-specified tolerance limit, no further measurements were taken at that site. The tolerance limits increased by 2 mm for every 10 mm measured. For the first two measures, the first measure represents the base. Thus, from 0-10 mm, observations were acceptable if they differed from the base measurement by 2 mm or less; from 10-20 mm, observations were acceptable if they differed from the base measurement by 4 mm or less; from 20-30 mm, observations were acceptable if they differed from the base measurement by 6 mm or less, and so on. If the difference between the two measurements at a given site did exceed the tolerance limit, each technician repeated and recorded a second measurement, resulting in a total of four measurements at that skinfold site. The summary skinfold values were computed as follows: If data were available for the third and fourth measurements and the difference between those measurements was within the specified tolerance limit, then the summary value was the mean of the third and fourth measurements. In all other cases, the summary value was the mean of all available skinfold measurements at that site. Tolerance: Tolerance was defined using the base skinfold measure. For the third and fourth measures, the third measure represents the base. If base > 0 and base <= 10 then tolerance is 2 mm If base > 10 and base <= 20 then tolerance is 4 mm If base > 20 and base <= 30 then tolerance is 6 mm If base > 30 and base <= 40 then tolerance is 8 mm If base > 40 then tolerance is 10 mm. This approach resulted in a single skinfold value for each of four anatomic locations in the final analytic data. These four locations were reported as triceps (BMPTRI), subscapular (BMPSUB), suprailiac (BMPSUP), and thigh (BMPTHI) skinfolds. BMPSUP: Suprailiac skinfold (mm) See note for BMPSUB. BMPTHI: Thigh skinfold (mm) See note for BMPSUB. BMPTRI: Triceps skinfold (mm) See note for BMPSUB. BMPWHR: Waist-to-hip ratio BMPWHR was calculated as BMPWAIST/BMPBUTTO. BMPWTFLG: Weight source flag See note for BMPHTFLG. BMPWTLBS: Weight (lbs) BMPWTLBS is weight converted to pounds from kilograms and was calculated as BMPWTLBS=BMPWT x 2.2. PEP12A1 and PEP12B1: BIA resistance and reactance (ohms) Data for bioelectrical impedance analysis (BIA) are considered a part of body measurements and have been included here with the body measurement data. However, the BIA resistance and reactance measures were recorded by the physicians in the Physician's Examination component, hence the "PEP" variable prefix. Analyses that may require the examiner identification for BIA data should use the physician examiner number (PEPTECH). BIA measurements are known to be affected by a variety of factors, including amputations, metal replacements, and pregnancy. Persons who were left-side amputees or had metal pins in their hips with hip replacements were not excluded from receiving the BIA procedure. However, in the data editing process, BIA resistance (PEP12A1) and BIA reactance (PEP12B1) data for persons with either right- or left-side amputations, who were pregnant, or who had metal pins in their hips were recoded to 8888. The "Blank but applicable" counts for PEP12A1 and PEP12B1 reflect cases in which persons were examined by the physician but in which the BIA procedure was not done for various reasons. The balance is accounted for by persons who were not examined by the physician. PEP12B1: BIA reactance (ohms) See note for PEP12A1. PEPPACE and PEPPREG: Pacemaker or pregnancy -- cannot obtain BIA To determine who should be excluded from receiving the BIA procedure as a safety precaution, examinees were asked if they had a pacemaker or were pregnant. PEPPREG was a self-reported variable and not an adjudicated assessment of pregnancy status; therefore, it should not be used as the definitive pregnancy variable (analysts are referred to MAPF12R and MYPC17 variables for pregnancy status).