Table of Contents

Component Description

Spirometry, which means “the measuring of breath,” is a routinely used clinical pulmonary function test. It measures the amount and speed of air that a person can exhale after taking in the deepest possible breath. This allows estimates for lung volume and air flow rates to be made. Results from Spirometry testing are one key element (among others) needed to diagnose respiratory disorders such as asthma and chronic obstructive pulmonary disease (COPD). These diseases are typically characterized by a reduction in expiratory air flow rates. This is defined in spirometry as a reduction in the ratio of the expiratory volume measured in the 1st second of a forceful exhalation (FEV1) to the total volume of air exhaled in the forced expiration (FVC), the FVC being an estimate of the individual's effective lung volume. The "Spirometric Measurements Section" of the NHANES 2007-8 Respiratory Health Spirometry Procedures Manual contains a basic explanation of interpreting spirometry data. The manual is available at https://wwwn.cdc.gov/nchs/data/nhanes/2007-2008/manuals/spirometry.pdf

Spirometry is one of two NHANES 2007-8 components on respiratory health sponsored by the National Heart, Lung, and Blood Institute of the National Institute of Health, the Centers for Disease Control and Prevention, National Institute for Health Statistics and the National Institute for Occupational Safety and Health (NIOSH). Individual Exhaled Nitrous Oxide (ENO), a marker of airways inflammation, is also measured. The objective of the Spirometry data collection is to provide health examination data to estimate the current prevalence of asthma and COPD in the U.S. population. The data is also intended to help produce updated spirometric reference data for the U.S. National-level Spirometry data was collected in NHANES I (1971-1975), NHANES II (1976-1980) and most recently in NHANES III (1988-1994). Comparisons of the current data with that from previous studies will help to identify trends in respiratory conditions over time.

Eligible participants performed an initial or "baseline" 1st test spirometry examination. Then a selected subsample of participants whose Baseline 1st Test Spirometry results showed a FEV1/FVC ratio below the lower limit of normal and/or below 70% were asked to repeat spirometry after inhaling a β2-adrenergic bronchodilator medication to open up their airways. This helps differentiate asthma from COPD (Pellegrino, Viegi, Brusasco, et al. 2005). Asthma patients usually show improvements in post-bronchodilator spirometry testing, while patients with COPD exhibit little, if any, response to the medication. Spirometric testing using β2-adrenergic bronchodilator is routinely employed by clinicians to diagnose asthma in both children and adults, and current clinical practice guidelines (NHLBI Expert Panel Report, 2007) consider post-bronchodilator spirometry testing essential for the initial diagnosis of asthma. Second test post bronchodilator spirometry studies had not been performed in previous NHANES surveys.

 

Eligible Sample

Survey participants, ages 6 to 79 years of age, were eligible for the Spirometry Component. Specific exclusion criteria that were employed for Baseline Spirometry included criteria employed in earlier NHANES Spirometry surveys. Excluded from testing were examinees that had current chest pain or a physical problem with forceful expiration, were taking supplemental oxygen, had recent surgery of the eye, chest or the abdomen; had a recent heart attack, stroke, tuberculosis exposure or had recently coughed up blood. Adults with a personal history of detached retina or a collapsed lung and children with painful ear infections were also excluded. In the NHANES 2007-8, Baseline (1st test) Spirometry data was collected for 6,444 sample persons.

Participants completing Baseline 1st test Spirometry were selected for follow-up Bronchodilator 2nd Test Spirometry only if their baseline spirometry values indicated possible airflow obstruction that might indicate the presence of asthma or COPD. The participant's baseline spirometry results were evaluated by a computerized algorithm and examinees with an FEV1/FVC% less than the Lower Limit of Normal (LLN) determined for his or her age, sex, weight, height, and race/ethnicity, or those who had a FEV1/FVC% less than 70% were considered eligible for bronchodilator testing. These two criteria were used so that NHANES data could be compared with previous epidemiology studies that used these two different criteria. For the first criterion the LLN for the FEV1/FEC was calculated based on the sample person's age, gender, height and race/ethnicity in three major groups (non-Hispanic white, non-Hispanic black, Mexican-American). For ages 8-79 the FEV1/FVC% LLN was as defined by NHANES III data (Hankinson, Odencrantz, Fedan, 1999) and for children ages 6-7 years it was as defined by Wang et al. (1993). The administrative variable SPDBRONC indicates whether the participant was considered eligible for Bronchodilator 2nd Test Spirometry. The variable SPXBSTAT provides the bronchodilator study exam status.

Participants eligible for Bronchodilator 2nd Test Spirometry were referred to the Mobile Examination Center (MEC) Physician for further evaluation as documented in the Respiratory Health Bronchodilator Procedures Manual. The Bronchodilator testing protocol was explained and the participant was further screened for the presence of any exclusion criteria for bronchodilator administration. These included certain cardiovascular conditions (uncontrolled blood pressure, irregular pulse on examination, taking medication for major arrhythmia, having an implanted defibrillator, or history of congenital heart disease) or taking certain prescription medications (a monamine oxidase inhibitor, an anticonvulsant, a tricyclic antidepressant plus current treatment for cardiac disease, potassium lowering drugs). Examinees were also excluded from bronchodilator administration if they had already recently taken a β2-adrenergic bronchodilator, or had a previous adverse reaction to albuterol. Women who were currently pregnant or breastfeeding were also excluded.

Following eligibility screening, the MEC physician obtained written informed consent and administered two puffs of the β2-adrenergic bronchodilator albuterol. The examinee was then required to wait a minimum of ten minutes before proceeding to the Spirometry exam room to obtain a repeat 2nd Test Bronchodilator spirometry study. A total of 611 sample persons performed Bronchodilator (2nd Test) Spirometry.

 

Protocol and Procedure

Testing procedures met the recommendations of the American Thoracic Society (ATS) (Miller, Hankinson, Brusasco el al. 2005). The protocol was similar to that used in NHANES III (1998-1994), with the minor change in the goal for the number of acceptable quality spirometry maneuvers, from five in NHANES III, to three in NHANES 2007-8. Also, to ensure data comparability between NHANES survey cycles, the same spirometers that were employed for the NHANES III spirometry examination (1988-1994) were used for NHANES 2007-8 data collection. These were Ohio 822/827 dry-rolling seal volume spirometers. The devices were reconditioned for use in the current survey and were maintained by the NIOSH laboratories. In NHANES 2007-8, unlike NHANES III, a new in-line biological filter (A-M Systems PFT Filter Kit B) was fitted to each spirometry hose to minimize infection risks to the participant.

Spirometry was performed in the standing position unless the participant was physically impaired. The participant was asked to elevate the chin and extend the neck slightly and place a nose clip on his or her nose during testing, the latter to prevent air leaks. He/she was then instructed to perform a series of maximal forced expiratory maneuvers. In each maneuver, the participant took the deepest breath possible to fill the lungs with air, then put the mouthpiece into his/her mouth making a tight seal and then blew the air out as hard and fast as possible. Participants ages 6-10 years were asked to blow out the air for a minimum of 3 seconds of exhalation, whereas those ages 11-79 years were asked to blow out the air for a minimum of 6 seconds of exhalation.

Spirometry testing for an individual continued until he/she was able to achieve a reproducible spirogram, or until a maximum of eight spirometry curves had been obtained, or until the participant could not continue. The overall goal was for the participant to achieve three acceptable exhalation maneuvers by ATS criteria in which the two highest values for the FVC and the FEV1 (each taken from an acceptable forced expiratory maneuver) showed minimal variability: i.e. the two largest FVC values taken from 2 acceptable curves should agree within 150 ml, and similarly for the two largest values for the FEV1. The procedure for the Bronchodilator (2nd Test) Spirometry, performed after the participant had taken the β2-adrenergic bronchodilator albuterol, was identical to the procedure for the Baseline 1st test. Please refer to the NHANES 2007-8 Repiratory Health Spirometry Procedure manual for full details on the testing protocol, and for detailed criteria for a reproducible spirogram.

 

Quality Assurance & Quality Control

The NIOSH Division of Respiratory Disease Studies served as the NHANES Spirometry training and quality control consultant. Each MEC Health Technician received formal training and satisfactorily completed the NIOSH-approved spirometry course. Additionally, all NHANES spirometry data were reviewed by expert reviewers at the NIOSH quality control center on an ongoing basis. MEC Technicians received continuous feedback on their performance throughout the survey.

The Respiratory Health Spirometry Procedures Manual provides detailed descriptions of the quality assurance and quality control measures that were used for the NHANES 2007-8 Spirometry examination. The Chief Health Technician at each MEC monitored ongoing staff performance in the field. Health technician performance was also monitored using direct observation at periodic site visits by NIOSH consultants and project officers from Westat (the data collection contractor) and NHANES. Spirometry equipment was kept in calibration via regularly scheduled quality control checks by the Health Technicians and these were verified by supervisory staff.

 

Data Processing and Editing

All spirometry data collected were reviewed by expert consultants at the NIOSH quality control center where data processing and editing were performed to ensure internal data consistency.

 

Analytic Notes

Summary results datasets are provided for both 1st and 2nd test Spirometry. These give the single best (highest) overall value for the following parameters taken from reproducible curves. Note that in this dataset, an individual best value for a specific variable could be taken from any of the individual acceptable curves that the participant performed. The summary data set format is similar to that previously released for the NHANES III data. The spirometry summary data release variables are: 

SPXNFVC   FVC: Forced Vital Capacity, ml (estimated lung volume)
SPXNEV  EV (ml): Extrapolated Volume, ml
SPXNFEV5  FEV0.5: Forced Expiratory Volume 1st 1/2 Second
SPXNFEV7  FEV0.75: Forced Expiratory Volume 1st 3/4 Second
SPXNFEV1  FEV1: Forced Expiratory Volume 1st Second
SPXNFEV3  FEV3: Forced Expiratory Volume 1st 3 Seconds
SPXNFEV6  FEV6 (ml): Forced Expiratory Volume 1st 6 Seconds
SPXNPEF  PEF: Peak Expiratory Flow Rate, ml/sec
SPXNF257  FEF25-75%: Forced Expiratory Flow Rate, Mid Exhalation, ml/sec
SPXNFET  FET: Forced Expiratory Time, sec

In addition, each summary dataset contains the following administrative variables:

The Number of Acceptable Curves
FVC Quality Rating
FEV1 Quality Rating
Examinee Effort Quality Rating

The following administrative variables are provided to support analysis of the summary best-test spirometry datasets.

FEV1 and FVC Quality Codes: These variables rate the quality of the summary best-test FEV1 and FVC values. The variables are SPXNQFVC and SPXNQFV1 for 1st Test Spirometry and SPXBQFVC and SPXBQFV1 for 2nd Test Spirometry. Quality of the FEV1 and FVC estimates was rated on a scale from A-F defined as follows:

A= Exceeds ATS data collection standards: 3 acceptable curves present and 2 reproducible curves; 2 observed values within 100 ml.
B= Meets ATS data collection standards: 3 acceptable curves present and 2 reproducible curves; 2 observed values within 150 ml.
C= Potentially usable value, but does not meet all ATS standards. Estimates usually based on 2 curve results with values within 200 ml. of each other.
D= Questionable result, use with caution
F= Results not valid

For those who want to perform analytic studies using data that excludes subjects that may not have perfect data, they should simply use data only with FEV1 and FVC quality grades A and B. Grade C indicates less than a perfect test, for example instances where there are only 2 acceptable curves achieved but where the data most likely represents a value where the subject made a maximal effort. Generally data with quality grades D and F are not used for data analysis. In the NHANES 2007-8 data collection 87% of summary best-test FVC estimates were of quality A or B, and 94% were of quality A, B, or C. For FEV1, 91% of summary best-test FVC estimates were of quality A or B, and 96% were of quality A, B, or C. When assessing data results, analysts may also want to take into consideration whether an examinee had a history of a recent respiratory illness such as a cold, which could potentially cause transient changes in spirometric values. The questionnaire variable ENQ100 captures a participant’s history of a recent respiratory illness.

Additional Variables Relating to Data Quality:
The summary spirometry datasets also provide a variable for the number of acceptable spirometry curves achieved by the participant judged by ATS criteria. These are the variables SPDNACC for Baseline 1st Test Spirometry and SPDBACC for Bronchodilator 2nd Test Spirometry. Also, data providing a summary rating of the overall spirometry curve quality for the participant are provided by the variables SPXNQEFF and SPXBQEFF.

Spirometry Exam Status Codes: Baseline 1st Test Spirometry has an overall exam status code (SPXNSTAT) which provides analysts with a single variable to identify those survey participants with complete or partial spirometry exams, those who were excluded from spirometry, or those who were eligible for spirometry but for whom the exam was not done. A similar variable (SPXBSTAT) is provided for the subset of participants who were selected for Bronchodilator 2nd Test Spirometry. For these variables a complete exam was defined as one in which both the best-test FEV1 and FVC estimates had quality ratings of A, B, or C. Partial exams were exams with any other spirometry data collected that was of lesser quality.

Spirometry Exam Comment Codes: Comment codes were added by the MEC Health Technicians, during data collection, to document the reasons why it was only possible to collect partial exam data for participants, and to document the reasons why Spirometry exams were not done if a participant was otherwise eligible. The comment code variable for Baseline 1st Test Spirometry is SPXNCMT, and for Bronchodilator 2nd test Spirometry it is SPXBCMT. Analysts may wish to review the comment code information for the Spirometry data prior to specific types of data analysis.

Sample Weights: The NHANES examination sample weights, i.e. the full sample 2-Year MEC Exam Weight (WTMEC2YR) should be used to analyze the 2007-8 spirometry data. Please refer to the NHANES Analytic Guidelines (https://wwwn.cdc.gov/nchs/nhanes/analyticguidelines.aspx) and the on-line NHANES Tutorial (https://www.cdc.gov/nchs/tutorials/) for further details on the use of sample weights and other analytic issues.

Additional 2007-8 NHANES Data on Respiratory Health:
The raw data for the spirometry curves attempted by each participant in the NHANES 2007-8 Spirometry Component is released in a separate dataset (SPXRAW_E). The raw data permits users to graph a participant's spirometry test curves. It is also intended for the use of data analysts who may want to perform more advanced modeling studies with the raw data. The NHANES 2007-8 Respiratory Health Component also included testing for Exhaled Nitric Oxide (ENX_E), and Household Inteview Questionaire data on a prior diagnosis of asthma and COPD (MCQ_E), recent respiratory symptoms such as cough and wheezing (RDQ_E), data for the participant's current prescription medications (RXQ_RX_E; RXQ_DRUG), and data for occupational risk factors for COPD (OCQ_E).

 

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 6 YEARS - 79 YEARS

ENQ010 - Breathing problem require oxygen?

Variable Name:
ENQ010
SAS Label:
Breathing problem require oxygen?
English Text:
{Do you/Does SP} currently have a breathing problem that requires {you/him/her} to use supplemental oxygen during the day? [This is air stored in a tank that you use to help you breathe. Do not include night treatments for sleep apnea.]
Target:
Both males and females 6 YEARS - 79 YEARS
Code or Value Value Description Count Cumulative Skip to Item
1 Yes 67 67 SPAENA
2 No 7090 7157
7 Refused 0 7157 SPAENA
9 Don't know 3 7160 SPAENA
. Missing 583 7743

ENQ020 - Problem taking deep breath?

Variable Name:
ENQ020
SAS Label:
Problem taking deep breath?
English Text:
{Do you/Does SP} now have any pain or physical problem that may prevent {you/him/her} from taking a deep breath and exhaling forcefully?
Target:
Both males and females 6 YEARS - 79 YEARS
Code or Value Value Description Count Cumulative Skip to Item
1 Yes 121 121 SPAENA
2 No 6967 7088
7 Refused 0 7088 SPAENA
9 Don't know 8 7096 SPAENA
. Missing 647 7743

SPQ010 - Have a current painful ear infection?

Variable Name:
SPQ010
SAS Label:
Have a current painful ear infection?
English Text:
{Do you/Does SP} now have a painful ear infection?
Target:
Both males and females 6 YEARS - 15 YEARS
Code or Value Value Description Count Cumulative Skip to Item
1 Yes 12 12 SPAENA
2 No 1790 1802
7 Refused 0 1802 SPAENA
9 Don't know 5 1807 SPAENA
. Missing 5936 7743

SPQ020 - Have you/Has SP ever had eye surgery?

Variable Name:
SPQ020
SAS Label:
Have you/Has SP ever had eye surgery?
English Text:
{Have you/Has SURVEY PARTICIPANT} ever had eye surgery? [Do not include cosmetic surgery on the eyelid or skin around the eye]
Target:
Both males and females 6 YEARS - 79 YEARS
Code or Value Value Description Count Cumulative Skip to Item
1 Yes 587 587
2 No 6361 6948 SPQ040
7 Refused 0 6948
9 Don't know 2 6950
. Missing 793 7743

SPQ030 - Eye surgery in the last 3 months?

Variable Name:
SPQ030
SAS Label:
Eye surgery in the last 3 months?
English Text:
Was the eye surgery in the last three months?
Target:
Both males and females 6 YEARS - 79 YEARS
Code or Value Value Description Count Cumulative Skip to Item
1 Yes 36 36 SPAENA
2 No 552 588
7 Refused 0 588 SPAENA
9 Don't know 1 589 SPAENA
. Missing 7154 7743

SPQ040 - Ever had open chest/abdominal surgery?

Variable Name:
SPQ040
SAS Label:
Ever had open chest/abdominal surgery?
English Text:
{Have you/Has SP} ever had open chest or abdominal surgery?
Target:
Both males and females 6 YEARS - 79 YEARS
Code or Value Value Description Count Cumulative Skip to Item
1 Yes 1111 1111
2 No 5802 6913 SPQ060
7 Refused 0 6913
9 Don't know 1 6914
. Missing 829 7743

SPQ050 - Chest/abdominal surgery last 3 months?

Variable Name:
SPQ050
SAS Label:
Chest/abdominal surgery last 3 months?
English Text:
Was the open chest or abdominal surgery in the last three months?
Target:
Both males and females 6 YEARS - 79 YEARS
Code or Value Value Description Count Cumulative Skip to Item
1 Yes 41 41 SPAENA
2 No 1070 1111
7 Refused 0 1111 SPAENA
9 Don't know 1 1112 SPAENA
. Missing 6631 7743

SPQ060 - Tuberculosis in last year?

Variable Name:
SPQ060
SAS Label:
Tuberculosis in last year?
English Text:
Did {you/SP} or anyone in {your/his/her} household have tuberculosis in the past year?
Target:
Both males and females 6 YEARS - 79 YEARS
Code or Value Value Description Count Cumulative Skip to Item
1 Yes 23 23 SPAENA
2 No 6848 6871
7 Refused 0 6871 SPAENA
9 Don't know 5 6876 SPAENA
. Missing 867 7743

SPQ070a - Ever told had an aneurysm?

Variable Name:
SPQ070a
SAS Label:
Ever told had an aneurysm?
English Text:
Has a doctor or other health professional ever told {you/SP}that {you/he/she} had . . .
English Instructions:
MARK ALL THAT APPLY
Target:
Both males and females 6 YEARS - 79 YEARS
Code or Value Value Description Count Cumulative Skip to Item
1 An aneurysm? 33 33 SPAENA
77 Refused 0 33 SPAENA
99 Don't know 2 35 SPAENA
. Missing 7708 7743

SPQ070b - Ever told had a collapsed lung?

Variable Name:
SPQ070b
SAS Label:
Ever told had a collapsed lung?
English Text:
Has a doctor or other health professional ever told {you/SP}that {you/he/she} had . . .
English Instructions:
MARK ALL THAT APPLY
Target:
Both males and females 6 YEARS - 79 YEARS
Code or Value Value Description Count Cumulative Skip to Item
2 a collapsed lung? 68 68 SPAENA
. Missing 7675 7743

SPQ070c - Ever told had a detached retina?

Variable Name:
SPQ070c
SAS Label:
Ever told had a detached retina?
English Text:
Has a doctor or other health professional ever told {you/SP}that {you/he/she} had . . .
Target:
Both males and females 16 YEARS - 79 YEARS
Code or Value Value Description Count Cumulative Skip to Item
3 a detached retina? 44 44 SPAENA
. Missing 7699 7743

SPQ070d - Ever told had a stroke?

Variable Name:
SPQ070d
SAS Label:
Ever told had a stroke?
English Text:
Has a doctor or other health professional ever told {you/SP}that {you/he/she} had . . .
Target:
Both males and females 16 YEARS - 79 YEARS
Code or Value Value Description Count Cumulative Skip to Item
4 a stroke? 133 133 SPQ080
. Missing 7610 7743

SPQ070e - Ever told had a heart attack?

Variable Name:
SPQ070e
SAS Label:
Ever told had a heart attack?
English Text:
Has a doctor or other health professional ever told {you/SP}that {you/he/she} had . . .
Target:
Both males and females 16 YEARS - 79 YEARS
Code or Value Value Description Count Cumulative Skip to Item
5 a heart attack? 140 140 SPQ090
. Missing 7603 7743

SPQ080 - Stroke in the last 3 months?

Variable Name:
SPQ080
SAS Label:
Stroke in the last 3 months?
English Text:
Did this stroke happen in the last three months?
Target:
Both males and females 16 YEARS - 79 YEARS
Code or Value Value Description Count Cumulative Skip to Item
1 Yes 6 6 SPAENA
2 No 114 120
7 Refused 0 120 SPAENA
9 Don't know 0 120 SPAENA
. Missing 7623 7743

SPQ090 - Heart attack in last 3 months?

Variable Name:
SPQ090
SAS Label:
Heart attack in last 3 months?
English Text:
Was {your/SP's} heart attack in the last three months?
Target:
Both males and females 16 YEARS - 79 YEARS
Code or Value Value Description Count Cumulative Skip to Item
1 Yes 3 3 SPAENA
2 No 120 123
7 Refused 0 123 SPAENA
9 Don't know 0 123 SPAENA
. Missing 7620 7743

SPQ100 - Coughed up blood past month?

Variable Name:
SPQ100
SAS Label:
Coughed up blood past month?
English Text:
In the past month, {have you/has SP} coughed up blood?
Target:
Both males and females 6 YEARS - 79 YEARS
Code or Value Value Description Count Cumulative Skip to Item
1 Yes 29 29 SPAENA
2 No 6682 6711
7 Refused 0 6711 SPAENA
9 Don't know 1 6712 SPAENA
. Missing 1031 7743

SPAENA - Check item

Variable Name:
SPAENA
SAS Label:
Check item
English Text:
Check item SPAENA
English Instructions:
If answered No in SPQ010, SPQ030, SPQ050, SPQ060, SPQ080, SPQ090, SPQ100, ENQ010, ENQ020, and Missing in SPQ070a, SPQ070b, SPQ070c set Spirometry to eligible, Otherwise set Spirometry Not Done/Safety Exclusion.
Target:
Both males and females 6 YEARS - 79 YEARS

ENQ100 - Had respiratory illness?

Variable Name:
ENQ100
SAS Label:
Had respiratory illness?
English Text:
In the past 7 days, {have you/has SP} had a cough, cold, phlegm, runny nose or other respiratory illness? Do not count allergies or hay fever.
Target:
Both males and females 6 YEARS - 79 YEARS
Code or Value Value Description Count Cumulative Skip to Item
1 Yes 1417 1417
2 No 5230 6647
7 Refused 0 6647
9 Don't know 3 6650
. Missing 1093 7743

SPXNSTAT - Spirometry First Test Status

Variable Name:
SPXNSTAT
SAS Label:
Spirometry First Test Status
English Text:
Spirometry First Test Status (Baseline Spirometry)
Target:
Both males and females 6 YEARS - 79 YEARS
Code or Value Value Description Count Cumulative Skip to Item
1 Complete Exam 6032 6032
2 Partial Exam 412 6444
3 Not Done 810 7254
4 Safety Exclusion 489 7743
. Missing 0 7743

SPXNCMT - Spirometry First Test Comment

Variable Name:
SPXNCMT
SAS Label:
Spirometry First Test Comment
English Text:
Spirometry First Test Comment (Baseline Spirometry)
Target:
Both males and females 6 YEARS - 79 YEARS
Code or Value Value Description Count Cumulative Skip to Item
2 SP refusal 80 80
3 No time 32 112
4 Physical limitation 67 179
5 Communication problem 64 243
6 Equipment failure 9 252
7 SP ill/emergency 26 278
14 Interrupted 4 282
27 Proxy no information 11 293
56 Came late/left early 526 819
84 SP with child 43 862
99 Other 71 933
. Missing 6810 7743

SPXNFVC - Baseline FVC (mL)

Variable Name:
SPXNFVC
SAS Label:
Baseline FVC (mL)
English Text:
Baseline 1st Test Spirometry, Forced Vital Capacity, in mL.
Target:
Both males and females 6 YEARS - 79 YEARS
Code or Value Value Description Count Cumulative Skip to Item
614 to 8084 Range of Values 6319 6319
. Missing 1424 7743

SPXNEV - Baseline Extrapolated Volume (mL)

Variable Name:
SPXNEV
SAS Label:
Baseline Extrapolated Volume (mL)
English Text:
Baseline 1st Test Spirometry, Extrapolated Volume, in mL.
Target:
Both males and females 6 YEARS - 79 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0 to 321 Range of Values 6318 6318
. Missing 1425 7743

SPXNFEV5 - Baseline FEV 0.5 (mL)

Variable Name:
SPXNFEV5
SAS Label:
Baseline FEV 0.5 (mL)
English Text:
Baseline 1st Test Spirometry, Forced Expiratory Volume in the first 0.5 seconds, in mL.
Target:
Both males and females 6 YEARS - 79 YEARS
Code or Value Value Description Count Cumulative Skip to Item
392 to 5520 Range of Values 6319 6319
. Missing 1424 7743

SPXNFEV7 - Baseline FEV 0.75 (mL)

Variable Name:
SPXNFEV7
SAS Label:
Baseline FEV 0.75 (mL)
English Text:
Baseline 1st Test Spirometry, Forced Expiratory Volume in the first 0.75 seconds, in mL.
Target:
Both males and females 6 YEARS - 79 YEARS
Code or Value Value Description Count Cumulative Skip to Item
432 to 6375 Range of Values 6319 6319
. Missing 1424 7743

SPXNFEV1 - Baseline FEV 1 (mL)

Variable Name:
SPXNFEV1
SAS Label:
Baseline FEV 1 (mL)
English Text:
Baseline 1st Test Spirometry, Forced Expiratory Volume in the first 1.0 second, in mL.
Target:
Both males and females 6 YEARS - 79 YEARS
Code or Value Value Description Count Cumulative Skip to Item
459 to 6770 Range of Values 6319 6319
. Missing 1424 7743

SPXNFEV3 - Baseline FEV 3 (mL)

Variable Name:
SPXNFEV3
SAS Label:
Baseline FEV 3 (mL)
English Text:
Baseline 1st Test Spirometry, Forced Expiratory Volume in the first 3.0 seconds, in mL.
Target:
Both males and females 6 YEARS - 79 YEARS
Code or Value Value Description Count Cumulative Skip to Item
424 to 7583 Range of Values 6319 6319
. Missing 1424 7743

SPXNFEV6 - Baseline FEV 6 (mL)

Variable Name:
SPXNFEV6
SAS Label:
Baseline FEV 6 (mL)
English Text:
Baseline 1st Test Spirometry, Forced Expiratory Volume in the first 6.0 seconds, in mL.
Target:
Both males and females 6 YEARS - 79 YEARS
Code or Value Value Description Count Cumulative Skip to Item
614 to 7856 Range of Values 6319 6319
. Missing 1424 7743

SPXNPEF - Baseline PEF (mL/s)

Variable Name:
SPXNPEF
SAS Label:
Baseline PEF (mL/s)
English Text:
Baseline 1st Test Spirometry, Peak Expiratory Flow Rate, in mL/s.
Target:
Both males and females 6 YEARS - 79 YEARS
Code or Value Value Description Count Cumulative Skip to Item
971 to 16723 Range of Values 6319 6319
. Missing 1424 7743

SPXNF257 - Baseline FEF 25-75% (mL/s)

Variable Name:
SPXNF257
SAS Label:
Baseline FEF 25-75% (mL/s)
English Text:
Baseline 1st Test Spirometry, Forced Expiratory Flow Rate 25-75%, in mL/s.
Target:
Both males and females 6 YEARS - 79 YEARS
Code or Value Value Description Count Cumulative Skip to Item
186 to 12776 Range of Values 6319 6319
. Missing 1424 7743

SPXNFET - Baseline Forced Expiratory Time (s)

Variable Name:
SPXNFET
SAS Label:
Baseline Forced Expiratory Time (s)
English Text:
Baseline 1st Test Spirometry, Forced Expiratory Time, in seconds.
Target:
Both males and females 6 YEARS - 79 YEARS
Code or Value Value Description Count Cumulative Skip to Item
1.1 to 32.8 Range of Values 6318 6318
. Missing 1425 7743

SPXNQFVC - Baseline FVC Quality Attribute

Variable Name:
SPXNQFVC
SAS Label:
Baseline FVC Quality Attribute
English Text:
Baseline 1st Test Spirometry, Forced Vital Capacity Quality Attribute.
Target:
Both males and females 6 YEARS - 79 YEARS
Code or Value Value Description Count Cumulative Skip to Item
A Exceeds ATS data collection standards 4435 4435
B Meets ATS data collection standards 1159 5594
C Potentially usable value, but does not meet all ATS standards 469 6063
D Questionable result, use with caution 211 6274
F Results not valid 170 6444
< blank > Missing 1299 7743

SPXNQFV1 - Baseline FEV1 Quality Attribute

Variable Name:
SPXNQFV1
SAS Label:
Baseline FEV1 Quality Attribute
English Text:
Baseline 1st Test Spirometry, Forced Expiratory Volume in the first 1.0 second Quality Attribute
Target:
Both males and females 6 YEARS - 79 YEARS
Code or Value Value Description Count Cumulative Skip to Item
A Exceeds ATS data collection standards 4804 4804
B Meets ATS data collection standards 1039 5843
C Potentially usable value, but does not meet all ATS standards 323 6166
D Questionable result, use with caution 142 6308
F Results not valid 136 6444
< blank > Missing 1299 7743

SPDNACC - Baseline Number of Acceptable Curves

Variable Name:
SPDNACC
SAS Label:
Baseline Number of Acceptable Curves
English Text:
Baseline 1st Test Spirometry, Number of Acceptable Curves Performed (ATS Criteria)
Target:
Both males and females 6 YEARS - 79 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0 to 10 Range of Values 6444 6444
. Missing 1299 7743

SPXNQEFF - Baseline Effort Quality Attribute

Variable Name:
SPXNQEFF
SAS Label:
Baseline Effort Quality Attribute
English Text:
Baseline 1st Test Spirometry, Effort Quality Attribute
Target:
Both males and females 6 YEARS - 79 YEARS
Code or Value Value Description Count Cumulative Skip to Item
A All 6 spirometry quality curve attributes are acceptable 5941 5941
B The curves had a large time to peak flow or a non-repeatable peak flow 134 6075
C The curves had either < 6 seconds of exhalation or no plateau 348 6423
D The curves had either a cough or large extrapolated volume 0 6423
< blank > Missing 1320 7743

SPDBRONC - Selected for Bronchodilator

Variable Name:
SPDBRONC
SAS Label:
Selected for Bronchodilator
English Text:
Best test FEV1/FVC ratio below Lower Limit of Normal and/or less than 70%
Target:
Both males and females 6 YEARS - 79 YEARS
Code or Value Value Description Count Cumulative Skip to Item
1 Yes 1001 1001
2 No 5443 6444
. Missing 1299 7743

SPXBSTAT - Spirometry Second Test Status

Variable Name:
SPXBSTAT
SAS Label:
Spirometry Second Test Status
English Text:
Spirometry Second Test Status (Post-Bronchodilator Spirometry)
Target:
Both males and females 6 YEARS - 79 YEARS
Code or Value Value Description Count Cumulative Skip to Item
1 Complete Exam 604 604
2 Partial Exam 7 611
3 Not Done 187 798
4 Safety Exclusion 203 1001
. Missing 6742 7743

SPXBCMT - Spirometry Second Test Comment

Variable Name:
SPXBCMT
SAS Label:
Spirometry Second Test Comment
English Text:
Spirometry Second Test Comment (Post-Bronchodilator Spirometry)
Target:
Both males and females 6 YEARS - 79 YEARS
Code or Value Value Description Count Cumulative Skip to Item
2 SP refusal 75 75
3 No time 6 81
4 Physical limitation 3 84
5 Communication problem 3 87
14 Interrupted 1 88
84 SP with child 1 89
99 Other 98 187
. Missing 7556 7743

SPXBFVC - 2nd Test FVC (mL)

Variable Name:
SPXBFVC
SAS Label:
2nd Test FVC (mL)
English Text:
Bronchodilator 2nd Test Spirometry, Forced Vital Capacity, in mL.
Target:
Both males and females 6 YEARS - 79 YEARS
Code or Value Value Description Count Cumulative Skip to Item
1211 to 7738 Range of Values 611 611
. Missing 7132 7743

SPXBEV - 2nd Test Extrapolated Volume (mL)

Variable Name:
SPXBEV
SAS Label:
2nd Test Extrapolated Volume (mL)
English Text:
Bronchodilator 2nd Test Spirometry, Extrapolated Volume, in mL.
Target:
Both males and females 6 YEARS - 79 YEARS
Code or Value Value Description Count Cumulative Skip to Item
11 to 214 Range of Values 611 611
. Missing 7132 7743

SPXBFEV5 - 2nd Test FEV 0.5 (mL)

Variable Name:
SPXBFEV5
SAS Label:
2nd Test FEV 0.5 (mL)
English Text:
Bronchodilator 2nd Test Spirometry, Forced Expiratory Volume in the first 0.5 seconds, in mL.
Target:
Both males and females 6 YEARS - 79 YEARS
Code or Value Value Description Count Cumulative Skip to Item
516 to 3758 Range of Values 611 611
. Missing 7132 7743

SPXBFEV7 - 2nd Test FEV 0.75 (mL)

Variable Name:
SPXBFEV7
SAS Label:
2nd Test FEV 0.75 (mL)
English Text:
Bronchodilator 2nd Test Spirometry, Forced Expiratory Volume in the first 0.75 seconds, in mL.
Target:
Both males and females 6 YEARS - 79 YEARS
Code or Value Value Description Count Cumulative Skip to Item
611 to 4757 Range of Values 611 611
. Missing 7132 7743

SPXBFEV1 - 2nd Test FEV 1 (mL)

Variable Name:
SPXBFEV1
SAS Label:
2nd Test FEV 1 (mL)
English Text:
Bronchodilator 2nd Test Spirometry, Forced Expiratory Volume in the first 1.0 second, in mL.
Target:
Both males and females 6 YEARS - 79 YEARS
Code or Value Value Description Count Cumulative Skip to Item
687 to 5431 Range of Values 611 611
. Missing 7132 7743

SPXBFEV3 - 2nd Test FEV 3 (mL)

Variable Name:
SPXBFEV3
SAS Label:
2nd Test FEV 3 (mL)
English Text:
Bronchodilator 2nd Test Spirometry, Forced Expiratory Volume in the first 3.0 seconds, in mL.
Target:
Both males and females 6 YEARS - 79 YEARS
Code or Value Value Description Count Cumulative Skip to Item
980 to 7136 Range of Values 611 611
. Missing 7132 7743

SPXBFEV6 - 2nd Test FEV 6 (mL)

Variable Name:
SPXBFEV6
SAS Label:
2nd Test FEV 6 (mL)
English Text:
Bronchodilator 2nd Test Spirometry, Forced Expiratory Volume in the first 6.0 seconds, in mL.
Target:
Both males and females 6 YEARS - 79 YEARS
Code or Value Value Description Count Cumulative Skip to Item
1120 to 7540 Range of Values 611 611
. Missing 7132 7743

SPXBPEF - 2nd Test PEF (mL/s)

Variable Name:
SPXBPEF
SAS Label:
2nd Test PEF (mL/s)
English Text:
Bronchodilator 2nd Test Spirometry, Peak Expiratory Flow Rate, in mL/s.
Target:
Both males and females 6 YEARS - 79 YEARS
Code or Value Value Description Count Cumulative Skip to Item
1496 to 14015 Range of Values 611 611
. Missing 7132 7743

SPXBF257 - 2nd Test FEF 25-75% (mL/s)

Variable Name:
SPXBF257
SAS Label:
2nd Test FEF 25-75% (mL/s)
English Text:
Bronchodilator 2nd Test Spirometry, Forced Expiratory Flow Rate 25-75%, in mL/s.
Target:
Both males and females 6 YEARS - 79 YEARS
Code or Value Value Description Count Cumulative Skip to Item
301 to 5465 Range of Values 611 611
. Missing 7132 7743

SPXBFET - 2nd Test Forced Expiratory Time (s)

Variable Name:
SPXBFET
SAS Label:
2nd Test Forced Expiratory Time (s)
English Text:
Bronchodilator 2nd Test Spirometry, Forced Expiratory Time, in seconds.
Target:
Both males and females 6 YEARS - 79 YEARS
Code or Value Value Description Count Cumulative Skip to Item
2.5 to 28.1 Range of Values 611 611
. Missing 7132 7743

SPXBQFVC - 2nd Test FVC Quality Attribute

Variable Name:
SPXBQFVC
SAS Label:
2nd Test FVC Quality Attribute
English Text:
Bronchodilator 2nd Test Spirometry, Forced Vital Capacity Quality Attribute.
Target:
Both males and females 6 YEARS - 79 YEARS
Code or Value Value Description Count Cumulative Skip to Item
A Exceeds ATS data collection standards 432 432
B Meets ATS data collection standards 132 564
C Potentially usable value, but does not meet all ATS standards 42 606
D Questionable result, use with caution 5 611
F Results not valid 0 611
< blank > Missing 7132 7743

SPXBQFV1 - 2nd Test FEV1 Quality Attribute

Variable Name:
SPXBQFV1
SAS Label:
2nd Test FEV1 Quality Attribute
English Text:
Bronchodilator 2nd Test Spirometry, Forced Expiratory Volume in the first 1.0 second Quality Attribute
Target:
Both males and females 6 YEARS - 79 YEARS
Code or Value Value Description Count Cumulative Skip to Item
A Exceeds ATS data collection standards 470 470
B Meets ATS data collection standards 113 583
C Potentially usable value, but does not meet all ATS standards 25 608
D Questionable result, use with caution 3 611
F Results not valid 0 611
< blank > Missing 7132 7743

SPDBACC - 2nd Test Number of Acceptable Curves

Variable Name:
SPDBACC
SAS Label:
2nd Test Number of Acceptable Curves
English Text:
Bronchodilator 2nd Test Spirometry, Number of Acceptable Curves Performed (ATS Criteria)
Target:
Both males and females 6 YEARS - 79 YEARS
Code or Value Value Description Count Cumulative Skip to Item
1 to 8 Range of Values 611 611
. Missing 7132 7743

SPXBQEFF - 2nd Test Effort Quality Attribute

Variable Name:
SPXBQEFF
SAS Label:
2nd Test Effort Quality Attribute
English Text:
Bronchodilator 2nd Test Spirometry, Effort Quality Attribute
Target:
Both males and females 6 YEARS - 79 YEARS
Code or Value Value Description Count Cumulative Skip to Item
A All 6 spirometry quality curve attributes are acceptable 595 595
B The curves had a large time to peak flow or a non-repeatable peak flow 0 595
C The curves had either < 6 seconds of exhalation or no plateau 14 609
D The curves had either a cough or large extrapolated volume 0 609
< blank > Missing 7134 7743