Table 2.

Prevalence of Different Definitions of TTFC by MD and HS Status in 1996

TTFC definitions (min)	Not MD, not HS, % 95% CI	Not MD, HS, % 95% CI	MD, not HS, % 95% CI	MD, HS, % 95% CI
≤5	11.0 (8.9–13.0)	34.7 (31.3–38.1)	24.6 (15.9–33.2)	58.3 (45.0–71.6)
6–30	31.0 (28.0–34.1)	42.8 (39.5–46.1)	27.9 (18.1–37.7)	31.2 (20.0–42.4)
31–60	21.5 (19.2–23.8)	16.4 (13.9–18.9)	20.7 (12.6–28.8)	6.9 (1.4–12.3)
>60	36.5 (33.4–39.5)	6.0 (4.4–7.7)	26.9 (17.6–36.1)	3.6 (2.7–6.9)

Note. HS status is based on smoking 20 or more cigarettes per day; HS = heavy smoking; MD = major depression; TTFC = time to first cigarette.