Table 3.

Smoking habits—Number and duration

Smoking status	Cases (n = 284)	Controls (n = 852)	OR	P value	95% CI
	Total (%)	Total (%)
Non-smokers	53 (18.7)	492 (57.8)
Total smokers	231(81.3)	360 (42.2)	5.9	0.0000	4.3, 8.4
Cigarette smokers	19 (6.7)	33 (3.9)	5.3	0.0000	2.7, 10.4
Bidi smokers	195 (68.7)	297 (34.8)	6.1	0.0000	4.3, 8.7
No. of bidis smoked/day
1–10	39	178	2.0	0.0029	1.3, 3.3
11–20	92	101	8.5	0.0000	5.6, 12.9
>20	64	18	33.0	0.0000	17.6, 63.2
Years of smoking bidi
1–20	36	88	3.8	0.0000	2.3, 6.3
21–39	131	177	6.9	0.0000	4.7, 10.1
≥40	28	32	8.1	0.0000	4.3, 15.1

CI = Confidence interval; OR = Odds ratio