The Get Quit - Stay Quit Study

"In the intervention group, if the lung age is equal to or less than the individual's chronological age, he or she will be briefly informed that the test result was normal and that it is important to avoid potential future lung problems by stopping smoking. For those in the intervention group with a normal FEV-1, the intervention will focus on their exhaled carbon-monoxide.~If their lung age is greater than their chronological age, they will be given their lung age in years, and provided with a graph describing the possible decline in lung age if they continued to smoke and a full explanation.~Those in the Intervention Group will have their exhaled carbon-monoxide (CO) result explained in more detail. Non-smokers typically have an exhaled carbon-monoxide level of 0-4 parts per million, whereas smokers typically have a CO level of 8-50 ppm. CO levels return to normal within a few days of stopping smoking. Participants are provided with a full explanation."

Those allocated to the control group will simply be informed of their scores on the spirometry.