title: Newer equations better predict lung age in smokers: a  retrospective analysis using a cohort of randomly selected  participants.
abstract: OBJECTIVE
  To produce new lung age equations using four previously published predictive equations for forced expiratory volume in 1 second  and to compare them with lung age equations published in 1985 and 2010.
  
  
  METHODS
  Initial comparisons used phantom subjects of different ages and levels of lung function. Comparison of lung age equations by  regression analysis used an independent dataset of 3,206 randomly selected community-dwelling adults aged >18 years in the North West  Adelaide Health Study.
  
  
  RESULTS
  The more recent equations estimated lung age as greater than chronological age as lung function decreased, whereas the oldest  equations estimated lung age as less than chronological age until lung function was severely limited. Significant differences (p<0.001) were  detected by regression analysis, with four newer lung age equations being significantly different from the 1985 equation and one being  no different.
  
  
  CONCLUSIONS
  Lung age estimates using six predictive equations spanning 50 years show differences attributable to cohort and period  effects. This reinforces the need for regular updating of predictive equations for lung function. These results further confirm the need to  use modern lung age equations which will provide a stronger message in smoking cessation counselling.
authors.affiliation: Discipline of General Practice, The University of Adelaide, Australia. wendy.newbury@adelaide.edu.au
authors.forename: Wendy
authors.initials: W
authors.lastname: Newbury
authors.forename: Michelle
authors.initials: M
authors.lastname: Lorimer
authors.forename: Alan
authors.initials: A
authors.lastname: Crockett
mesh_terms: D000328:Adult; D015331:Cohort Studies; D005260:Female; D005541:Forced Expiratory Volume; D006801:Humans; D008168:Lung / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D008962:Models, Theoretical; D012189:Retrospective Studies; D012907:Smoking / Q000009:adverse effects*; D016540:Smoking Cessation; D014029:Tobacco Use Disorder