Reporting spirometry results as “lung age” v simple forced expiratory volume at 1 second (FEV₁) to promote smoking cessation*

Outcomes at 12 months	Results reported as lung age	Results reported as FEV₁	RBI (95% CI)	NNT (CI)
Verified smoking cessation	14%	6.4%	112% (25 to 261)	14 (9 to 45)
			Difference in means (CI)
Daily cigarette consumption (mean)	12	14	−2.0 (−3.8 to −0.2)

*Abbreviations defined in glossary. RBI, NNT, and CI calculated from data in article.

*Abbreviations defined in glossary. RBI, NNT, and CI calculated from data in article.