Abstract
Background: Lung age is a simple concept for patients to grasp and frequently used as an aid in smoking cessation programmes. Lung age equations need to be reviewed for relevance to target populations.
Aim: To assess how new lung age equations developed for Australian populations performed on BOLD-Australia dataset compared to previously used equations.
Methods: Cross-sectional study of Australians aged ≥40yrs. Spirometry performed using the ndd EasyOneTM in accordance with ERS/ATS guidelines; analysis restricted to Caucasians <75yrs. Lung ages calculated using gender specific Newbury W. et al [PCRJ 2010;19:242] and Morris & Temple [Prev Med 1985; 14:655] equations, were compared by age within and across smoking status.
Results: 2,793 participants with mean age of 57 (±SD 10) yrs; 52% ever smoked, 10.4% were current smokers and GOLD Stage I or higher COPD was 13.4% (95%CI: 12.2, 14.7). For both genders, recent Newbury equations estimated lung ages significantly older than actual age regardless of smoking status (p<.05). Morris equations estimated significantly lower lung age for never and former smokers (p<.05), and no difference among current smokers for either gender. Effect of smoking on lung age was similar for both equations; lung age among the exposed was older than never smokers (p<.001) after adjusting for age. Lung age also increased with increased pack-years.
Conclusions: Findings support use of updated equations suited to the population of interest. The Newbury equations performed well in BOLD-Australia dataset providing more meaningful lung age profile compared to chronological age, among smokers.
Support: National Health and Medical Research Council.
- © 2014 ERS