Details Pertaining to Pulmonary Function

Principal Investigator: James Fozard
Collaborating Investigators: (none)
Year First Collected: 1958
Year Last Collected: 1973
Frequency of Collection: n/a
Subset Data Files on the VMS Cluster? Files info115.*, Inactive as of 11/97. Available to all users authorized to access Common BLSA Data Set.

Data Type Notes: Descriptive History: Data Collection Instrument/Method/Medium: Related Protocols: info115 **pi James Fozard Information type 115, This is an earlier version of summary data.

Pulmonary Data reviewed by statistical studies, LSB
This includes Information Types 110-117 subject to modification 11/97.

Clarification of data element descriptions:

Card one, cols 01-01, names equipment used in spirometry, real time' refers to most recent equipment used. On that equipment, the spirogram, the flow volume record of the test, was generated on the computer as the test maneuver was being performed. On earlier equipment, a paper record was generated, that was later traced with an electronic pen to give records comparable to the most recent.

Card one, cols 02-02, names persons who traced the paper records with electronic pens.

Card one, col's 03-06, is a numerical name of record for purposes of evaluation at the central quality control laboratory.

Card one, col's 07-07, judgement of whether record was of acceptable quality by staff of the central quality control laboratory. The checks were performed on a random subset of records collected on the most recent equipment used.

Card one, cols 08-08, judgement of quality of spirogram by American Thoracic Society criteria for research quality spirograms.

Card one, cols 09-22, multiple trials were performed by each participant, and the two best records were evaluated as shown in the data explanation. Second best means that the value of the second was within about 5% of the first best.

Card one, cols 23-29, is a temperature and temperature correction factor used in calculations.

Card one, cols 30-33, FEV1/Predicted FEV1. FEV indicates the volume of a maximally fast expiration starting from a full inspiration. The numerical subscript, e.g., FEV1, is the time in seconds over which FEV is measured, one second in this example. Predicted FEV1 is the expected value (from BLSA data in our case) predicted from height, age and sex. This explanation applies to all variables that includes "predicted."

Card one, cols 34-37, FVC Predicted. Total volume expired.
Card one, cols 38-46, as defined above.
Card one, cols 47-50, Predicted PEFR. Peak expiratory flow rates in one sec.
Card one, cols 51-66, all involve FEF. This is a forced expiratory flow at a designated volume point, or between two designated volume points. The values in these variables are 25%, 50%, and 75% of the total expiration. Columns 63-66 define the FEF between the 25th and 75th percentiles of the time volume curve that represents FVC.

Card two, cols 01-44, are the observed values for the participant as opposed to the predicted.
Card two, cols 46-49, is the calculated percentile ranking of FEV1/ Height squared.
Card two, cols 50-53, is the observed ratio of FEV1/Height squared.

Card two, cols 54-57, maximum inspiratory pressure, not available on early data.

The data on Card 1 of Information types 110, 111, and 112 were the original data from which the data on Information Type 118 were derived. I do not recommend their use. The data on Card two of these information types concerned a study of "Nitrogen Washout" which was reported in an unpublished thesis by Michael Baser. I would not recommend further use of those data.
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Revised 12/09/98 -- Send comments to our Web Master .