Smokeless Tobacco and Oral Cancer in South Asia: A Systematic Review with Meta-Analysis

Table 3

Epidemiological studies of chewing paan with tobacco and oral cancer.

Authors	OR (95% CI)	Men; OR (95% CI)	Women; OR (95% CI)	Daily frequency/intensity**			Total duration of use***
				Paan ≤ 5  OR (95% CI)	Paan 6–10 OR (95% CI)	Paan > 10 OR (95% CI)	Paan ≤ 10 yrs OR (95% CI)	Paan 11–20 yrs OR (95% CI)	Paan > 20 yrs OR (95% CI)
Sankaranarayanan et al. [29]^a	6.1 (3.2–5.7)	3.6*	6.5*	3.3 (1.6–6.9)	2.3 (1.2–4.6)	6.1 (2.8–13.2)	4.7*	2.4*	5.0*
Sankaranarayanan et al. [30]^a	8.7 (3.5–21.4)	9.0*	11.3*	4.7 (2.2–10.0)	4.0 (1.9–8.4)	13.2 (6.2–27.8)	3.4*	4.0*	14.6*
Sankaranarayanan et al. [31]^a	14.1 (7.4–26.5)	10.9*	7.3*	6.0*	9.5*	15.7*	7.1 (2.7–18.2)	4.4 (2.4–8.1)	n/a
Wasnik et al. [36]	9.4 (5.1–17.4)	n/a	n/a	n/a	n/a	n/a	n/a	n/a	n/a
Merchant et al. [38]	8.4 (2.3–30.6)	n/a	n/a	n/a	n/a	n/a	n/a	n/a	n/a
Balaram et al. [39]	15.7 (11.0–22.1)	6.1 (3.8–9.7)	45.8 (25.0–84.1)	8.5 (5.4–13.3)	19.4 (10.8–27.0)	24.7 (12.5–48.7)	n/a	n/a	n/a
Subapriya et al. [41]	3.1*	n/a	n/a	n/a	n/a	n/a	n/a	n/a	n/a
Muwonge et al. [44]	5.4 (3.8–7.7)	3.4 (2.2–5.2)	11.8 (6.0–23.3)	3.7 (2.4–5.5)	5.8 (3.9–8.7)	7.8 (4.8–12.7)	n/a	n/a	5.6*
Ray et al. [49]	3.9 (2.4–6.4)	1.5 (0.7–3.0)	8.5 (4.6–15.5)	n/a	n/a	n/a	n/a	n/a	n/a

OR: odds ratio, CI: confidence interval, *95% CI not reported and/or could not be calculated from given data, **daily frequency in number of times paan is chewed in a day, ***total duration of habit in “years,” n/a: not available, and ^athe difference between overall and stratum specific OR is because the overall OR and some dose response OR are adjusted for smoking and alcohol while others were calculated using MH method. Nonchewers are taken as reference category. Frequency/intensity OR are for both genders.