Table 1. The distribution of 205 cases of cervical carcinoma and 213 controls with corresponding odds ratios (OR) and 95% confidence intervals (CI) by selected characteristics (Chennai, 1998–1999).

	No. Cases	%	No. Controls	%	OR (95% CI)b
Age (years)
<45	70	34.1	73	34.3	—
45–49	44	21.5	44	20.6	—
⩾50	91	44.4	96	45.1	—
Human papilloma-virus DNA
Negative	1	0.5	133	72.3	1c
Positive	190	99.5	51	27.7	387.7 (82.2–7443.8)
Education
High	22	10.7	62	29.1	1c
Primary	22	10.7	48	22.5	1.42 (0.59–3.43)
None	161	78.5	103	48.4	2.69 (1.25–5.79)
χ21 for trend					7.53; P=0.006
Occupation
Housewife	34	16.6	99	46.5	1c
Farmer	140	68.3	74	34.7	4.33 (2.30–8.15)
Other	31	15.1	40	18.8	1.52 (0.70–3.32)
Marital status
Married	143	69.8	201	94.4	1
Widow	55	26.8	12	5.6	8.11 (3.57–18.43)
Separated-divorced	7	3.4	0	0.0
Age at first marriage/cohabiting (years)
⩾21	20	9.8	36	16.9	1
19–20	39	19.0	41	19.3	1.23 (0.48–3.14)
17–18	53	25.9	69	32.4	0.76 (0.32–1.84)
15–16	45	22.0	32	15.0	0.74 (0.28–1.95)
<15	48	23.4	35	16.4	0.80 (0.31–2.10)
χ21 for trend					0.92; P=0.337
Number of pregnancies
<3	34	16.6	70	32.9	1
3–4	85	41.5	90	42.3	3.06 (1.54–6.10)
⩾5	86	42.0	53	24.9	4.99 (2.37–10.49)
χ21 for trend					17.26; P<0.001
Husband's extramarital affairsd
No	58	28.6	156	73.6	1
Uncertain/yes	145	71.4	56	26.4	6.99 (4.08–12.00)

^aSome strata do not add up to the total because of missing values.

^bEstimates from unconditional regression equations, including terms for age and area of residence, education, occupation, marital status, age at first marriage, number of pregnancies and husband's extramarital affairs.

^cReference category.

^dIncluding prostitutes.