Table 2

Chewing tobacco habits and risk of erythroplakia (ORs and 95% CIs)

CasesControlsCrude OR (95% CI)Adjusted ORa (95% CI)Further adjusted ORb (95% CI)
Chewing tobacco
No chewing934,3731.01.01.0
Ever chewing9113,40025.9 (13.1–51.5)20.6 (10.2–41.5)19.8 (9.8–40.0)
Chewing tobacco
No chewing934,3731.01.01.0
Past101,27629.9 (12.1–13.5)26.8 (13.1–54.7)25.8 (12.6–52.8)
Occasional22,6252.9 (0.6–13.5)2.4 (0.5–11.1)2.3 (0.5–10.9)
Current799,49931.7 (15.9–63.3)29.4 (11.6–74.6)27.6 (10.8–70.4)
Frequency of chewing (times per day)
Continuous1.05 (1.03–1.07)1.04 (1.02–1.06)1.04 (1.02–1.06)
No chewing934,3731.01.01.0
1–10608,99125.5 (12.6–51.4)23.8 (11.5–49.3)28.6 (14.0–58.7)
11–20181,44347.6 (21.4–106.2)39.1 (17.0–90.1)49.8 (22.0–113.1)
≥2011271155.0 (63.7–377.1)100.4 (39.3–256.8)130.8 (52.5–326.3)
Missing22,695
P for trend0.00010.00010.0001
Duration of chewing (yr)
Continuous1.01 (0.99–1.02)1.02 (1.00–1.04)1.01 (0.99–1.03)
No chewing934,3731.01.01.0
1–20425,97126.9 (13.1–55.2)23.7 (11.3–49.6)29.3 (14.2–60.8)
21–40383,47041.8 (20.2–86.6)41.4 (19.0–90.1)53.3 (24.7–114.8)
≥4091,21728.2 (11.2–71.3)40.6 (14.0–117.4)52.8 (18.3–152.6)
Missing22,742
P for trend0.00010.00010.0001
Swallow chewing tobacco fluid
No chewing934,3731.01.01.0c
Chewing/no swallowing7710,11729.1 (15.6–58.0)26.6 (13.0–54.4)20.8 (9.8–44.4)
Chewing/Swallowing9291118.1 (46.6–299.7)83.0 (31.5–218.6)50.6 (17.9–143.4)
Occasionally swallow330337.8 (10.2–140.4)23.2 (6.0–89.2)14.5 (3.6–58.9)
Missing22,689
Keep chewing tobacco in mouth overnight
No chewing934,3731.01.01.0c
Chewing/Don’t keep8210,35130.3 (15.2–60.2)27.3 (13.4–55.8)21.2 (10.0–45.2)
Chewing/Keep731086.2 (31.9–233.0)64.6 (23.0–181.4)36.3 (11.9–111.6)
Missing22,687
  • a OR adjusted for age (continuous), sex (M/F), education (categories from Table 2<$REFLINK> ), and BMI (continuous, kg/m2).

  • b OR adjusted for age, sex, education, BMI, smoking (continuous, pack-years), and drinking (continuous, duration in years).

  • c OR adjusted for age, sex, education, BMI, smoking, drinking, and tobacco chewing (years and times per day).