Gastric cancer risk in relation to tobacco use and alcohol drinking in Kerala, India - Karunagappally cohort study

Table 1 Sociodemographic features of study subjects (men) and their associations with gastric cancer

	n	Person-years	Gastric cancer cases	RR	95%CI	P value
Total	65553	900721
Religion						> 0.52
Hindu	47689	658303	88	1.0	Reference
Muslim	11841	160475	19	0.9	0.5-1.5
Christian	6023	81942	9	0.8	0.4-1.6
Family income3						0.1911
< 500	4367	66066	10	1.1	0.6-2.2
501-1200	19460	281461	41	1.0
1201-2500	24794	332258	37	0.7	0.5-1.1
2501-3500	10839	141566	14	0.6	0.3-1.0
3500+	6093	79370	14	1.0	0.5-1.8
Education						0.1641
Illiterate	4143	52337	7	0.5	0.2-1.1
Primary school	16917	221434	49	1.0	Reference
Middle school	17310	238947	30	0.7	0.5-1.2
High school	20775	298699	25	0.7	0.4-1.1
College	5703	79877	4	0.4	0.1-1.1
Unknown	705	9427	1	0.5	0.1-3.9
Occupation						0.0082
Farmers and fishermen	21683	302651	51	1.0	Reference
Skilled workers	12445	169094	21	0.8	0.5-1.3
White collars	13672	183094	28	0.8	0.5-1.2
Others	17753	245882	16	0.4	0.2-0.7

¹The P for trend;

²The P for heterogeneity;

³Monthly family income in Indian National Rupee (INR). One INR is approximately 0.016 US dollars. In the analysis examining the relation between socioeconomic status and gastric cancer risk, a relative risk was obtained from the following model: H = H_s exp (B_iX_i), where the background hazard, H_s, was stratified by attained age and calendar time, and X_i denotes categorical variables of the sociodemographic factors shown in the table.