Figure 1.

Kaplan-Meier curve for lung cancer diagnosis, comparing subjects with no acute respiratory exacerbations reported in the 12 months prior to study enrollment (n = 387) vs those with one or more reported exacerbations (n = 87). Subjects were followed up for 8 years; those who died without lung cancer or were lost to follow-up were censored as marked. HRs are based on an unadjusted analysis of time to lung cancer diagnosis. This analysis was limited to cases with an annotated lung cancer diagnosis date and the matched control subjects. HR = hazard ratio.