Table 2.

Crude odds ratios for CCA associations with various risk factors

Characteristics	Cases (n = 210)	Controls (n = 840)	Crude OR	95 % CI	P-value
Number of PZQ treatments (times)	-	-	1.33	1.16 - 1.51	<0.001
Number of PZQ treatments (times)					<0.001
0	48.5	65.9	1	-
1	32.9	24.4	1.93	1.35 - 2.77
2	8.6	4.9	2.72	1.45 - 5.07
More than 2	10.0	4.8	3.20	1.75 - 5.74
Test for linear trend (1df)					<0.001
Highest educational attainment					0.003
Primary school	79.1	68.1	1	-
Secondary school	3.8	6.2	0.51	0.24 - 1.10
High school or Diploma	9.5	10.5	0.76	0.45 - 1.28
Bachelor’s degree	7.6	15.2	0.40	0.23 - 0.71
Herbicide use					0.375
No	79.5	82.0	1	-
Yes	20.5	18.0	1.20	0.80 - 1.80
Rodenticide use					0.001
No	70.5	81.1	1	-
Yes	29.5	18.9	1.81	1.28 - 2.57
Insecticide use					0.884
No	87.6	87.3	1	-
Yes	12.4	12.7	0.97	0.60 - 1.56
Fungicide use					0.421
No	96.7	97.6	1	-
Yes	3.3	2.4	1.45	0.58 - 3.61
Smoking behavior					0.045
Never smoked	45.2	50.1	1	-
Smoker	54.8	49.9	1.74	1.01 - 3.00
Alcohol use					0.030
Never used	33.8	40.0	1	-
Drinkers	66.2	60.0	1.60	1.05 - 2.45
Salted fresh water fish, salted meat					0.474
No	11.0	12.7	1	-
Yes	89.0	87.3	1.19	0.73 - 1.94
Raw, partially cooked raw fish (e.g. Lap-Pla, Koi-Pla)					<0.001
No	38.6	61.7	1	-
Yes	61.4	38.3	3.10	2.18 - 4.40
Fermented product (e.g. Pla-chao, Pla-chom)					<0.001
No	23.3	35.1	1	-
Yes	76.7	64.9	1.87	1.30 - 2.71
Grilled/smoked meat					0.892
No	1.4	1.3	1	-
Yes	98.6	98.7	0.91	0.25 - 3.36
Chinese sausage/other sausages
No	35.2	23.0	1	-	<0.001
Yes	64.8	77.0	0.54	0.38 - 0.75
Fermented fish (Pla-ra)					0.041
No	1.4	4.6	1	-
Yes	98.6	95.4	3.5	1.06 - 11.5
History of cancer in family					<0.001
No	50.0	72.1	1	-
Yes	50.0	27.9	2.56	1.87 - 3.51
Combining variables
Local nitrite-containing foods					0.156
No	57.6	62.9	1
Yes	42.4	37.1	1.25	0.92 - 1.71
Environmental chemical use					<0.001
No	55.7	68.7	1
Yes	44.3	31.3	1.81	1.31 - 2.50