Table 1. Distributions and odds ratios of OL and OSF associated with demographic factors, Taiwan.

	Oral leukoplakia			Oral submucous fibrosis
Factor/category	No. of cases	No. of controls	OR (95% CI)	No. of cases	No. of controls	OR (95% CI)
Age (years)
<31	5	20		22	88
31–40	37	148		38	152
41–50	31	124		16	64
>50	52	208		18	72
Gender
Male	118	472		93	372
Female	7	28		1	4
Ethnicity
Fukienese	97	378	1.0	71	287	1.0
Mainlander	14	54	1.0 (0.5–2.1)	10	35	1.1 (0.5–2.5)
Hakka	11	65	0.7 (0.3–1.3)	11	50	0.9 (0.4–1.8)
Aborigines	3	3	3.9 (0.8–19.6)	2	4	2.2 (0.3–13.4)
Years of education
<7	74	259	1.0	37	110	1.0
7–9	21	84	0.8 (0.4–1.4)	19	78	0.6 (0.3–1.2)
>9	30	157	0.6 (0.3–0.9)	38	188	0.4 (0.2–0.8)
Occupation
Blue collar	77	269	1.0	56	183	1.0
Farmer	25	90	1.0 (0.6–1.7)	15	49	1.1 (0.5–2.2)
White collar	23	141	0.6 (0.3–0.9)	23	144	0.5 (0.3–0.9)