Table 2

Cases and controls in the classes of independent variables, odds ratios (OR), 95% exact confidence intervals (CI), χ² test for trend (χ²_trend), and p values for two tailed tests

	Cases	Controls	OR	CI	χ²_trend
*p<0.01; †p<0.001; ‡p<0.0001.
Smoking habits
Non-smokers	2	103	Reference
Smokers, 1–10 cigarettes	1	37	1.39	0.02 to 27.4
Smokers, 11–20 cigarettes	23	67	17.7‡	4.10 to 157.0	39.87‡
Smokers, ⩾21 cigarettes	12	17	36.4‡	6.90 to 347.0
Age at end of follow up or death
45–57 years	11	75	Reference
58–65 years	17	68	1.71	0.69 to 4.32	0.14
66–82 years	10	81	0.84	0.30 to 2.33
VCM cumulative exposure
⩽392 ppm×years	16	71	Reference
393–1650 ppm×years	13	74	0.78	0.32 to 1.87	2.35
⩾1651 ppm×years	9	79	0.51	0.18 to 1.31
Circumstances of exposure to PVC dust
None of the following	8	87	Reference
PVC compounding	8	49	1.78	0.54 to 5.78
Baggers (unknown length)	5	55	0.99	0.24 to 3.63
Baggers (known length)	17	33	5.60†	2.03 to 16.3
PVC compounding
No	30	175	Reference
⩽8.0 years	4	23	1.10	0.24 to 3.28	0.64
>8.0 years	4	26	0.90	0.21 to 2.86
Baggers: duration of job
No	21	191	Reference
<3.6 years	6	19	2.87	0.84 to 8.56	22.84‡
⩾3.6 years	11	14	7.15‡	2.55 to 19.3
Baggers: calendar year at onset of job
No	21	191	Reference
Before 1967	10	19	4.79†	1.73 to 12.5
Since 1967 onwards	7	14	4.55†	1.38 to 13.6
Baggers: age at onset of job
No	21	191	Reference
Until 33 years	6	20	2.73	0.80 to 8.07
Over 33 years	11	13	7.70‡	2.72 to 21.1
Baggers: time elapsed from onset of job to end of follow up or death
No	21	191	Reference
>20 years (distant exposure)	12	29	3.76*	1.51 to 8.99
⩽20 years (recent exposure)	5	4	11.4*	2.21 to 60.7