Table 1

Demographic characteristics of the 'breast cancer' and 'screening control' groups.

CHARACTERISTICS

CASES

CONTROLS

P VALUE


Age

N

847

712

P < 0.01#

Median (IQR)

62 (54–70)

57 (53–61)

Ever Smoked

N

844

712

P < 0.01~

Yes

295 (35%)

316 (44.4%)

No

549 (65%)

396 (55.6%)

Post Menopausal

N

849

712

P = 0.34~

Yes

547 (64.4%)

476 (66.9%)

No

302 (35.6%)

236 (33.1%)

Age at Menarche

N

840

709

P = 0.05#

Median (IQR)

13 (12–14)

13 (12–14)

Age at Menopause

N

485

420

P = 0.38#

Median (IQR)

50 (46–52)

50 (47–52)

Number of children

N

849

712

P < 0.01#

Median (IQR)

2 (1–3)

2 (2–3)

Age at first pregnancy

N

705

646

P < 0.01#

Median (IQR)

24 (21–27)

23 (20–26)

Family history of breast cancer

N

850

712

P < 0.01~

Yes

234 (27.5%)

153 (21.5%)

No

616 (72.5%)

559 (78.5%)


IQR – Inter quartile range;

# – Mann Whitney U test; ~- Chi square test with continuity correction

Balasubramanian et al. BMC Cancer 2007 7:107   doi:10.1186/1471-2407-7-107

Open Data