How to diagnose airway obstruction
Version 126.96.36.199 - (3.8 MB)
The software has been significantly expanded and enhanced. It now also includes the predicted values and their Lower Limits of Normal for FEV1, FVC and FEV1%FVC, with full documentation in an associated Help file, making it the most complete reference of prediction equations available.
Please note: this software is for use by professionals and useless for laymen.
The Pulmonaria Group have designed software that runs on a PC. It allows one to compare the lower limits of normal for FEV1%VC and for FEV1 according to published reference equations with the GOLD criterion for airway obstruction. Unlike published equations, the GOLD committee recommends to regard an FEV1%FVC < 70% (after bronchodilatation) as indicative of airway obstruction.
The software displays the lower limit of normal for FEV1%FVC according to over 80 publications (above), and for FEV1 and FVC, for different ethnic groups from various parts of the world. Any predicted value below this (GOLD) 70% limit is shown in red (GOLD stage 1) and purple (GOLD stage 2). Predicted values not only vary with age, but according to most authors also with standing height. The software allows you to manipulate age and height, highlight the predicted value according to any of the listed authors, and provides you with a numerical display in addition to the graphs.
If one adopts a fixed cut-off, so that any FEV1%FVC below 70% is regarded as airway obstruction, then how does this affect the interpretation of test results? Use real data from healthy lifelong nonsmokers to find out. To that end the software provides you with data on well over 50,500 subjects: healthy lifelong non-smokers, normal populations (such as shown below) and hospital populations.
The help file documents in detail all reference equations used, and also provides a background for the interpretation of lung function tests.
You can not only compare reference equations graphically and numerically (top illustration), but also enter measured data and assess how they compare with any of the sets of predicted values (right). In the case of airway obstruction you can grade the severity according to ATS/ERS, BTS, GOLD and other organisations, by clicking on the severity button.
March 29, 2007: you can now enter FEV1 and FVC and evaluate these against various prediction equations.
April 4, 2007: compare evaluation of FEV1 and FVC according to ERS, ATS, GOLD, NICE, ATS/ERS and Pulmonaria Group.
April 13, 2007: select your preferred set of prediction equations. Now 61 authors of prediction equations included.
April 18, 2007: Marsh (NZ) and 4 Chinese authors of prediction equations added.
May 4, 2007: We apologise: clicking 'Start' did not work. We apologise for the inconvenience.
May 7, 2007: Resolved various bugs.
Aug. 22, 2007: Resolved a couple of minor bugs.
Nov. 6, 2007: Added Latin American prediction equations due to Perez-Padilla et al. and resolved minor issues.
Nov. 24, 2007: Added prediction equations for Pakistani due to Memon et al.
Nov. 25, 2007: Known issue. On some computers the start button will not show up on the splash screen. In that case click on the cross in the right upper corner (see bitmap on the right) to close the screen, and you can proceed using the software.
Feb. 27, 2008: Added prediction equations due to Pistelli (2x) and Kuster.
March 6, 2008: Added prediction equations due to Smolej-Narancic and Mustajbegovic.
March 13, 2008: Added predicted values for 4-80 yr range due to Stanojevic et al.
March 21, 2008: Resolved that some authors were not displayed when selecting Caucasians.
May 21, 2008: Added prediction equations due to Kivastik and Pereira.
May 22, 2008: Corrected error in FEV1/FVC females, Pereira.
Aug. 5, 2008: Added predicted values for south Indian children age 7-19, from Vijayan
Oct. 4, 2008: Corrected errors in predicted values for Jia, China, added Perez-Padilla Mexican youths
Oct. 16, 2008: Corrected minor error in Hankinson African-Americans boys 18 yr
July 14, 2009: Various corrections: Mustajbegovic and Smolej-Narancic may have been swapped in the past, problem with 'Evaluate data' for Kuster males corrected, and some minor issues.
July 17, 2009: Minor corrections.
July19-20-21-23, 2009: Very much indebted to Phillip Gillies, who pointed out many bugs which have now been corrected.
October 16, 2009: errors in predicted values for Hou females corrected.
March 12, 2010: Vista and Windows 7 no longer support help files, so replaced help file with a pdf file.