Choosing and using lung function prediction equations

Abstract

@ERSpublicationsThe GLI-2012 reference equations give the best fit for patients undergoing spirometry lung function testing http://ow.ly/NikG304sh0nIn a survey of lung function laboratories some years ago, a surprisingly large number of laboratories were found not to know exactly which equations were being used to help them make judgements about their patients' results [1]. Many manufacturers' equipment includes a choice of reference values and the default selection may end up being used without further or due consideration. When choosing which equations to use, laboratory directors and clinicians may worry that their patients might be assessed against an inappropriate standard, thus introducing potential errors in their decision making. The European Respiratory Society has sponsored the Global Lung Function Initiative (GLI) in obtaining coherent reference equations for spirometry appropriate for all ages [2] and advocates these being the standard applied for spirometry within Europe. In this issue of the European Respiratory Journal (ERJ), two groups of European researchers have looked at their local populations to see if the GLI-2012 equations were a satisfactory fit and so can be safely used for clinical decision making [3,4]. HULO et al. [3] looked at the data of 1971 people aged 40-65 years from an urban population who were symptom free and were part of a study of 3276 subjects who were sampled to determine the prevalence of airflow obstruction in the general population. The mean±SD z-scores for forced expiratory volume in 1 s (FEV1) and forced vital capacity (FVC) by GLI-2012 were close to 0.0±1.0, as expected, and were better than the scores found when using the European Community for Steel and Coal (ECSC) equations [5]. Their subjects' FEV1/FVC results were slightly low relative to GLI-2012, with mean z-scores of −0.32 and −0.40 for men and women, respectively, but they were not able to account for smoking in their population, which may have influenced this. They also looked at how the two equations fared at identifying abnormalities in another 1072 subjects with respiratory disease and concluded that the GLI-2012 equations were better than the ECSC equations in this respect. LANGHAMMER et al.[4] used data from 11 496 Norwegian subjects across an age range of 12-90 years who were healthy never-smokers without symptoms. They found that the median z-scores for FEV1, FVC and FEV1/FVC were essentially zero in those aged <20 years, with female adults tending to have very slightly better FEV1 and FVC and lower FEV1/FVC than the values predicted by GLI-2012 (median z-scores 0.15, 0.25 and −0.17, respectively). They concluded that GLI-2012 was a better fit for their data than either the ECSC or an alternative Norwegian prediction equation, and recommended GLI-2012 for Norwegian subjects. They also applied GLI-2012 to a larger population including symptomatic subjects (n=50 580) and concluded that GLI-2012 was better than FEV1/FVC <0.7 at identifying clinically relevant airflow obstruction.Both these studies fo...

Lung Function Testing and Prediction Equations in Adult Population from Maputo, Mozambique

“…As the differences were substantial in some subjects, our findings are relevant for clinical practice. They suggest that individuals from certain ethnic groups might be incorrectly diagnosed and treated for pulmonary conditions due to the application of an inappropriate reference standard to their spirometry results [25]. However, we cannot exclude that lung damage is prevalent in a certain proportion of our clinically asymptomatic study participants.…”

“…Ethnicity has been recognized to play a significant role in the variability of lung function, thus it is important to establish reference values relevant to the ethnic characteristics of the local population [23][24][25]. In this study, we have generated prediction equations for FVC and FEV1 as well as for the ratio of FVC/FEV1 based on lung function data from 155 healthy adults living in Maputo, Mozambique.…”

Does the level of obesity impact on the respiratory function in adults?

“…Usually, manufacturers' equipment includes a choice of reference values and the default selection may end up being used without further or due consideration. There is a plethora of published reference equations, mostly for spirometric indices, with most equations being based on small numbers of subjects, while using data collected decades ago so that changes in spirometric methodology and secular trends may affect their applicability to present-day measurements [52]. For example, in their interesting study on the effects of body mass index on lung volumes, Jones et al used the reference values proposed by Gutierrez C et al for Canadian Caucasians [53].…”

The Effect of Innovative Potential on Small Business Performance

“…Small business is a basic form of doing business in most developed and developing countries of the world. It is dominant in quantitative terms and exerts a significant influence on socioeconomic development, including macroeconomic parameters such as: creation and management of new markets, growth of gross domestic product, wealth generation, demonopolization of the economy, dynamics of international economic exchange, development of entrepreneurial skills and capabilities, job creation and job satisfaction (Mubaraki & Aruna, 2013;McCann & Ortega-Argilés, 2016;Muller et al, 2016). The ability to conduct innovative activities and successfully implement innovations should be one of key factors in achieving these macroeconomic successes and building the competitiveness of small business (Urbancová, 2013;Aziz & Samad, 2016).…”