SPIROMETRY Lung function testing (spirometry) was conducted on examinees aged eight years and older by a trained technician in the mobile examination center (MEC). It also was conducted at the home of examinees aged 60 and over who were unwilling or unable to come to the MEC. Before testing, screening questions were asked to determine medical safety exclusions. Those excluded from testing were examinees who had undergone chest or abdominal surgery within three weeks or had experienced heart problems (myocardial infarction or heart attack, angina or chest pain, congestive heart failure) within six weeks before the MEC exam. 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 weights should be used (WTPFEX6). For more information on the use of sample weights in NHANES III data analysis, refer to the Analytic and Reporting Guidelines (U.S. DHHS, 1996b). Spirometry is a widely used test of lung function that measures both the volume of air in the lung and how quickly a person can move the air out of the lung. A testing session consisted of repeated forced vital capacity (FVC) maneuvers. Each maneuver required the examinee to take the deepest possible breath and exhale into a spirometer as hard, fast, and completely as possible. The spirometer recorded the volume of air exhaled as a function of time from which a number of parameters were measured. Each examinee attempted to perform at least five FVC maneuvers. The testing procedure was explained and demonstrated to each examinee by a spirometry technician. The computer provided immediate feedback on the examinee's effort, and the technician used that information to actively coach the examinee through each trial. For a maneuver to be acceptable, it had to be a maximal exhalation free from a cough, excessive hesitation, a leak, an obstructed mouthpiece, variable effort, or early termination. An additional goal was that the examinee have a sufficient number of trials to demonstrate that the FVC and forced expiratory volume(FEV1) values were reproducible. Aside from using a different type of spirometer flow-type (see SPPTYPE) in home examinations, technicians used procedures comparable to those used in the MEC. Therefore, the home spirometry values were incorporated into the MEC spirometry measures data set. Refer to the Spirometry Examination Manual (U.S. DHHS, 1996b) and the Home Exam Manual (U.S. DHHS, 1996b) for descriptions of data collection procedures and methods. Testing procedures met the recommendations of the American Thoracic Society (American Thoracic Society, 1987). The National Institute for Occupational Safety and Health (NIOSH) served as the spirometry quality control center. Each spirometry technician received at least one week of formal training and satisfactorily completed a NIOSH-approved course on spirometry. Additionally, spirometry data were reviewed by the quality control center at the completion of each location, and technicians received continuous feedback on their performance. 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 ------------------------------------------------------------------------ SPIROMETRY ------------------------------------------------------------------------ SCREENING QUESTIONS ------------------------------------------------------------------------ Positions Item description SAS name Counts and code Notes ------------------------------------------------------------------------ 4447 In the past three weeks have you had any SPPQ1 surgery on your chest or abdomen? 4 1 Yes (End) 20923 2 No 1516 8 Blank but applicable 8868 Blank 4448 Have you been hospitalized for a heart SPPQ2 problem (i.e., heart attack, angina or chest pain, congestive heart failure) within the past six weeks? 9 1 Yes (End) 20917 2 No 1517 8 Blank but applicable 8868 Blank 4449 Have you smoked a cigarette, eaten a SPPQ3 heavy meal, or used any medications to help your breathing in the past hour? 287 1 Yes 20629 2 No 1515 8 Blank but applicable 8880 Blank 4450 In the past few days have you had a SPPQ4 cough, cold, or other acute illness? 4228 1 Yes 16688 2 No 1515 8 Blank but applicable 8880 Blank 4451 In the past three weeks have you had any SPPQ5 respiratory infections, such as flu, pneumonia, bronchitis, or a severe cold? 1077 1 Yes 19839 2 No 1515 8 Blank but applicable 8880 Blank NHANES III Examination Data File ------------------------------------------------------------------------ SPIROMETRY ------------------------------------------------------------------------ HOME EXAMINATION ------------------------------------------------------------------------ Positions Item description SAS name Counts and code Notes ------------------------------------------------------------------------ 4452 Position for home examination HXPEJ6A2 239 1 Standing 129 2 Sitting 77 8 Blank but applicable 30866 Blank NHANES III Examination Data File ------------------------------------------------------------------------ SPIROMETRY ------------------------------------------------------------------------ DATA ------------------------------------------------------------------------ Positions Item description SAS name Counts and code Notes ------------------------------------------------------------------------ 4453-4457 Examiner number SPPTECH1 20977 01001-09018 1454 88888 Blank but applicable 8880 Blank 4458-4459 Number of forced vital capacity (FVC) See note SPPTRIAL trials attempted 54 00 Zero 20932 01-16 1445 88 Blank but applicable 8880 Blank 4460-4464 Peak expiratory flow, largest See note SPPPEAK value (ml) 20835 00125-17980 1596 88888 Blank but applicable 8880 Blank 4465-4468 Forced expiratory volume (FEV) at 0.5 See note SPPFEV05 second, largest value (ml) 20599 0050-4941 1832 8888 Blank but applicable 8880 Blank 4469-4472 FEV1 at 1.0 second, largest value (ml) See note SPPFEV1 20835 0104-6572 1596 8888 Blank but applicable 8880 Blank 4473-4477 FEV3 at 3.0 seconds, largest value (ml) See note SPPFEV3 20599 00230-07608 1832 88888 Blank but applicable 8880 Blank 4478-4482 FEV6 at 6.0 seconds, largest value (ml) See note SPPFEV6 20599 00347-07811 1832 88888 Blank but applicable 8880 Blank NHANES III Examination Data File ------------------------------------------------------------------------ SPIROMETRY ------------------------------------------------------------------------ DATA ------------------------------------------------------------------------ Positions Item description SAS name Counts and code Notes ------------------------------------------------------------------------ 4483-4487 FVC, largest value (ml) See note SPPFVC 20835 00361-07845 1596 88888 Blank but applicable 8880 Blank 4488-4492 Maximum mid-expiratory flow See note SPPMMEF (ml/sec best curve) 20599 00056-08913 1832 88888 Blank but applicable 8880 Blank 4493 Spirometer type See note SPPTYPE 20585 1 MEC exam, NIOSH volume spirometer 53 2 Home exam, MultiSpiro flow spirometer 97 3 Home exam, Riko flow spirometer 101 4 Home exam, NIOSH flow spirometer 1595 8 Blank but applicable 8880 Blank 4494 Reproducibility code See note SPPREPRO 1182 1 FVC not reproducible 62 2 FEV1 not reproducible 309 3 Neither FVC nor FEV1 reproducible 19283 4 Both FVC and FEV1 reproducible 1595 8 Blank but applicable 8880 Blank 4495 Review evaluation See note SPPRELIA 20743 1 Test reliable 241 2 Test unreliable 1447 8 Blank but applicable 8880 Blank 4496-4497 Number of acceptable trials See note SPPMANEU 150 00 Zero 20836 01-16 1445 88 Blank but applicable 8880 Blank NHANES III Examination Data File ------------------------------------------------------------------------ SPIROMETRY ------------------------------------------------------------------------ DATA ------------------------------------------------------------------------ Positions Item description SAS name Counts and code Notes ------------------------------------------------------------------------ 4498-4502 Time of day test was conducted (hh:mm) SPPTIME 20599 08:00-21:37 1832 88888 Blank but applicable 8880 Blank 4503-4504 Expiratory time of trial with See note SPPEXPIR largest FVC (sec) 20793 00-25 1638 88 Blank but applicable 8880 Blank 4505-4508 FEF at 75% of FVC (ml) See note SPPFEF75 20599 0050-5427 1832 8888 Blank but applicable 8880 Blank 4509-4510 Spirometer internal temperature (Celsius)See note SPPTEMP 20816 12-32 1615 88 Blank but applicable 8880 Blank NHANES III Examination Data File ------------------------------------------------------------------------ THIS PAGE INTENTIONALLY LEFT BLANK NOTES SPPEXPIR: Expiratory time of the trial with the largest forced vital capacity (FVC)(sec) The time (seconds) it took to reach the largest FVC. SPPFEF75: Flow at 75% of FVC (ml/second) This was the flow rate (ml/second) at 75% of the FVC. Values were obtained from the "best curve" or the curve with the largest sum of FEV1 plus FVC. SPPFEV05: Forced expiratory volume (FEV) at 0.5 seconds (ml) The volume (ml) of air exhaled during the first 0.5 second of a forced vital capacity maneuver. The volume reported is the largest volume achieved from all acceptable FVC maneuvers. SPPFEV1: Forced expiratory volume at 1 second (ml) The volume (ml) of air exhaled during the first second of a forced vital capacity maneuver. The volume reported is the largest volume achieved from all acceptable FVC maneuvers. SPPFEV3: Forced expiratory volume at 3 seconds (ml) The volume (ml) of air exhaled during the first three seconds of a forced vital capacity maneuver. The volume reported is the largest volume achieved from all acceptable FVC maneuvers. SPPFEV6: Forced expiratory volume at six seconds (ml) The volume (ml) of air exhaled during the first six seconds of a forced vital capacity maneuver. The volume reported is the largest volume achieved from all acceptable FVC maneuvers. SPPFVC: Forced vital capacity, largest value (ml) The total volume (ml) of air exhaled during a forced vital capacity maneuver. The volume reported is the largest volume achieved from all acceptable FVC maneuvers. SPPMANEU: Number of acceptable trials The number of FVC maneuvers that met the ATS acceptability criteria. SPPMMEF: Maximum mid-expiratory flow (ml/second best curve) The mean forced expiratory flow during the middle half of the FVC maneuver. Values were obtained from the "best curve" defined as the curve with the highest sum of FVC and FEV1. SPPPEAK: Peak expiratory flow (ml/second) The maximum expiratory flow (ml/sec) observed from all acceptable FVC maneuvers. SPPRELIA: Test evaluation All tests were reviewed by two senior quality technicians at the spirometry quality control center and classified for reliability. Tests deemed unreliable should not be used because the quality technicians determined that the results were of insufficient quality to be usable. SPPREPRO: Reproducibility code In accordance with ATS guidelines, all unacceptable maneuvers were excluded before the reproducibility calculations were performed. The goal during test performance was to obtain a reproducible FVC (largest FVC and second largest FVC within 5%) and a reproducible FEV1 (largest FEV1 and second largest FEV1 within 5%). The reproducibility code indicates whether a reproducible FVC and/or FEV1 was obtained. SPPTEMP: Spirometer internal temperature (Celsius) This was the internal temperature inside the spirometer measured at the end of the FVC maneuver. SPPTRIAL: Number of forced vital capacity (FVC) trials attempted This was the total number of forced vital capacity maneuvers attempted by the sample person. SPPTYPE: Spirometer type Four different types of spirometers were used; one type was used in MEC spirometry exams, and three different types were used in home spirometry exams. The MEC spirometers (type=1) were customized, Ohio 822 or 827, dry, rolling-seal spirometers and were interfaced to a microcomputer. For home spirometry, the three types of flow spirometers used were: MultiSpiro (type=2), Riko model AS-600 (type=3), and NIOSH (type=4). The MultiSpiro- and Riko-brand spirometers produced paper tracings with digital readings of FVC and FEV1. These spirometers provided neither quality assessments of the subject's effort nor some of the spirometry variables measured in the MEC. The NIOSH flow spirometer measured all of the parameters measured by the MEC spirometer and provided a display of the subject's flow-volume curve with a computer-determined quality assessment equivalent to the assessment provided by the spirometer used in the MEC.