Cigarette smoking raises the probability that an individual will get lung cancer, chronic bronchitis and/or emphysema (among many other things). Nicotine is addictive and smokers often need significant motivation in order to quit. Lung age is a tool that was designed to give smokers an additional incentive to do this. The concept is fairly simple and that is by reformulating an FEV1 reference equation it is possible to take an individual’s actual FEV1 and estimate the age of their lungs (ELA). Because cigarette smoking can cause airway obstruction it tends to mimic premature lung aging which means that when a smoker’s FEV1 is used to calculate an ELA it can be significantly greater than their real or chronological lung age (CLA).
This idea was first proposed by Morris and Temple in 1985. Using Morris et al’s 1971 spirometry reference equations they studied the effect of calculating an estimated lung age (ELA) using observed FVC, FEV1 and FEF25-75 values both singly and in combinations and found that the FEV1 had the lowest standard error. The ELA calculation based on Morris et al’s FEV1 reference equations has achieved a degree of popularity and is available on at least one personal spirometer (Pulmolife, sold by Carefusion, MDSpiro and Vitalograph) and as an on-line calculator from a couple different websites (Chestx-ray.com and Lung Foundation of Australia).
Interestingly, the effectiveness of ELA towards quitting smoking has been studied only a handful of times. One often-quoted study of smoking cessation (Parkes et al) saw double the quit rate (13.6% vs 6.4%) when ELA was used as an intervention but the study’s methodology has since been criticized and it’s results have not been duplicated.