time to first cigarette risk_factor_for COPD

The risk of COPD was higher among smokers with shorter TTFC... ORs ... for COPD were 1.48, 1.64, 2.18 (P-trend <0.0001).

a single question, such as TTFC, which could be used as a screening tool for COPD risk in smokers

we detected a robust significant increased risk of COPD with shortened TTFC

We used logistic regression models to estimate the COPD odds ratios for each TTFC category, with TTFC >60 minutes as the referent group.

Among African Americans, those with shorter TTFC had the greatest risk of COPD and emphysema...

shorter TTFC ... was strongly associated with increased risk of COPD

current smokers with shorter TTFC had greater risk of COPD compared to those with longer TTFC (>60 minutes)

current smokers who report COPD ... may be enriched with individuals with shorter TTFC, ... overestimate the association between TTFC and COPD