Software for interpreting pulmonary function
The LungXplorer software is designed to become familiar with real data collected in a normal population. The database comprises
Some 14,500 longitudinal spirometric measurements (FEV1, FVC) in about 4,500 adults (18-80+ yr). Data were collected in a normal population at 3 year intervals for up to 12 years.
About 6,200 longitudinal measurements (FEV1, FVC) in about 750 adolescent schoolchildren, who were about 11-12 years old at the start of the study. Data were collected at half year intervals for up to 7 years.
Associated flow-volume curves
Predicted values and their lower ‘limits of normal’
A computer-generated interpretation, employing the same algorithms that are used in SpirXpert, the professional software for interpreting tests of pulmonary function (available from our website)
Explore the database both cross-sectionally and longitudinally. Data will only be displayed longitudinally if at least two measurements were available within a person. You can come to grips with:
Variation in the shape of MEFV curves in health and disease, during growth and ageing.
Interpreting spirometric data, i.e. FEV1, (F)VC and their ratio.
Expressing spirometric data relative to predicted values.
Check whether individuals track along predicted values.
Download free software (5.1 MB) Upgraded March 14, 2010
This software is designed to help you quickly check whether measured values for FEV1, FEV1%FVC and FVC in adults are within normal limits, using the three most popular prediction equations in the USA.
Why may this software be useful to you?
· It is particularly useful if you are making, or considering, the transition from a previous set of regression equations to NHANES III and you want to check how this would change your assessments of results.
· In addition it is invaluable as a stand-alone product, because you do not have to start your specialized spirometer software and then generate a person of specific height, age, ethnic group and gender. With this software it is a breeze.
The multilingual software is available in Dutch, English, French, German and Italian. You can change languages on the fly. It provides professional interpretation of pulmonary function tests pre- and post-bronchodilator. You can select from among 18 prediction equations for adults, and 17 for children and adolescents.
Consult the help file for further details about this software (925 KB).
Upgraded Aug. 3, 2009: anyone who owns a licence is entitled to free updates and upgrades. The new version complies with the ATS/ERS 2005 guidelines.
In order to properly interpret spirometric data one needs to know predicted values and their lower limits of normal. How well do predicted values for children and adolescents connect to those for adults? The set that I am using, or plan to be using, how does it compare to other predicted values? How to handle different ethnic groups? You will find the answers in this software, which displays predicted values and their LLN of 68 authors, and in the very extensive documentation that accompanies it.
There is increasing awareness that using a fixed ratio of 0.70 for the lower limit of FEV1%FVC leads to over-diagnosis of COPD in middle-aged and elderly subjects, and to significant under-diagnosis in younger adults. This is exacerbated by the use of a fixed 80%predicted lower limit for FEV1. The Pulmonaria Group have assembled overwhelming evidence to that effect. They have compiled all evidence in both software and a very comprehensive help file.
This software shows you graphically the Lower Limit of Normal according to regression equations from 72 published studies, leading to 78 regression equations for women and 8o for men, for different ethnic groups, and for FEV1%FVC, FVCand FEV1. There is also numeric display of these LLNs.
You can also enter spirometric data and inspect how they compare to the various predicted values.
In addition there are data from over 50,000 subjects: hospital patients (St. Louis, USA and Rotterdam, NL), the NHANES III population, the Lung Health Study for England 1995/1996, a study by Gore (AUS), and a longitudinal study of two Dutch populations. These data are used to visualize the false-positive and false-negative rates, the predictive value of negative and positive test results, in the various populations. All regression equations and their Lower Limits of Normal are documented in the extensive help file.
A full list of references to the literature is available here.
This software is solely designed to allow you to explore and familiarize with real clinical data. The database comprises about 12,000 sets of spirometric measurements obtained in adults and in some children/adolsecents. Measurements were usually performed pre en post bronchodilator in clinical and outpatients.
The SpirXplorer software is provided with a database comprising about 12,000 spirometric measurements obtained in clinical and outpatients, from adolescents to over 90 yrs old. In the majority of cases tests were repeated after bronchodilatation.
Recently facilities became available to describe the pattern of pulmonary function from childhood to old age using smoothing splines. At the same time account could be taken of the fact that the variability in predicted values is age dependent, being appreciably larger in young children and people of old age than in between these ages. Finally corrections can be made for non-normal distributions. These sets of predicted values were pioneered by the Institute of Child Health, University College London, in a collaborative project (The Asthma UK Collaborative Initiative). As of 2010 these are the state of the art prediction equations for FEV1, FVC, FEV1/FVC and FEF25-75% in Caucasians aged 3-80 yr, and for FEV0.75 in children aged 3-16 yr.