The Global Lung Function Initiative 2012 Equations Are as Well-Suited as Local Population Derived Equations to a Sample of Healthy Professional Firefighters

Abstract

Background and Objective We aimed to assess the validity of using the Global Lung Function Initiative's (GLI) 2012 equations to interpret lung function data in a healthy workforce of South Australian Metropolitan Fire Service (SAMFS) personnel. Methods Spirometry data from 212 healthy, nonsmoking SAMFS firefighters were collected and predicted normal values were calculated using both the GLI and local population derived (Gore) equations for forced expiratory volume in one second (FEV1), forced vital capacity (FVC), and FEV1/FVC. Two-tailed paired sample Student's t-tests, Bland-Altman assessments of agreement, and z-scores were used to compare the two prediction methods. Results The equations showed good agreement for mean predicted FEV1, FVC, and FEV1/FVC. Mean z-scores were similar for FEV1 and FVC, although not FEV1/FVC, but greater than 0.5. Differences between the calculated lower limits of normal (LLN) were significant (p < 0.01), clinically meaningful, and resulted in an 8% difference in classification of abnormality using the FEV1/FVC ratio. Conclusions The GLI equations predicted similar lung function as population-specific equations and resulted in a lower incidence of obstruction in this sample of healthy SAMFS firefighters. Further, interpretation of spirometry data as abnormal should be based on both an FEV1 and FEV1/FVC ratio < LLN.

The Effect of Fire Smoke Exposure on Firefighters’ Lung Function: A Meta-Analysis

“…Several studies based their conclusions on the published predicted values of spirometric indices (FEV 1 and FVC), which have been reviewed or modified over the years. The Global Lung Function Initiative developed in 2012 (GLI-2012) reports the latest reference equations for spirometry, based on the pooled resources of various countries and on data obtained from more than 74,000 healthy non-smokers tests from all over the world [ 62 , 63 ]. To date, the GLI database is the one in force and is used by most of the researchers and health care professionals, hampering an appropriate comparison between studies.…”

“…Several studies reported that in Australia the selection process to become a firefighter demands undergoing physical and psychological health and fitness tests and, once accepted, the selected individuals have to perform regular and intensive medical examinations. In addition, if they are not sufficiently healthy and fit, they are excluded and cannot proceed in their firefighter career [ 60 , 62 ].…”

“… Predicted FEV 1 in firefighters stratified by studies’ publication year. Forest plot displaying the weight of the predicted FEV 1 mean value and heterogeneity [ 13 , 40 , 41 , 42 , 43 , 44 , 45 , 46 , 47 , 48 , 49 , 50 , 51 , 52 , 53 , 54 , 55 , 56 , 57 , 58 , 59 , 60 , 61 , 62 ]. …”

“…Forest plot displaying the weight of the predicted FEV 1 mean value and heterogeneity. “Non-smokers” was assigned to all the studies wherein less than or equal to 10% of the participants were smokers, and “Smokers” was assigned to the studies wherein more than 10% of the participants were smokers [ 13 , 40 , 41 , 42 , 43 , 44 , 45 , 46 , 47 , 48 , 49 , 50 , 51 , 52 , 53 , 54 , 56 , 57 , 58 , 59 , 60 , 61 , 62 ].…”

<p>Impacts of Different Spirometry Reference Equations and Diagnostic Criteria on the Frequency of Airway Obstruction in Adult People of North China</p>

“…8 Previous studies showed that the applicability of GLI-2012 was different in different countries or populations. [9][10][11][12][13][14] However, the values of GLI-2012 in North Chinese have not been fully investigated yet.…”