Table 1 Comparison of clinical characteristics before matching data between the two groups
From: Relationship between formulaic breast volume and risk of breast cancer based on linear measurements
Covariates | Control group | Case group | Test statistics | P value |
|---|---|---|---|---|
Age | 50.4 (45.0, 54.0) | 50.7 (45.0, 57.0) | U = 34,589.00 | 0.668 |
BMI | 23.48 (21.10, 25.26) | 23.72 (21.23, 26.04) | U = 33,110.50 | 0.211 |
Menarche age | 14.9 (13.0, 16.0) | 14.3 (13.0, 15.0) | U = 29,130.00 | < 0.001 |
Age at first pregnancy | 23.7 (21.0, 26.0) | 24.3 (22.0, 26.0) | U = 30,871.50 | 0.012 |
Number of pregnancies | 3.0 (2.0, 4.0) | 3.0 (2.0, 4.0) | U = 31,835.50 | 0.045 |
Feeding mode | χ2 = 0.350 | 0.554 | ||
Breastfeeding | 316 (92.9%) | 196 (94.2%) | ||
Non-breastfeeding | 24 (7.1%) | 12 (5.8%) | ||
Proliferative benign breast disease | χ2 = 0.984 | 0.321 | ||
Yes | 107 (31.5%) | 74 (35.6%) | ||
No | 233 (68.5%) | 134 (64.4%) | ||
Oral contraceptives | χ2 = 0.009 | 0.923 | ||
Yes | 27 (7.9%) | 17 (8.2%) | ||
No | 313 (92.1%) | 191 (91.8%) | ||
Smoking | χ2 = 1.638 | 0.201 | ||
Yes | 0 | 1 (0.5%) | ||
No | 340 (100%) | 207 (99.5%) | ||
Alcohol consumption | χ2 = 4.230 | 0.121 | ||
No risk | 325 (95.6%) | 193 (92.8%) | ||
Low risk | 15 (4.4%) | 13 (6.3%) | ||
High risk | 0 | 2 (1.0%) | ||
History of hyperthyroidism | χ2 = 0.292 | 0.589 | ||
Yes | 9 (2.6%) | 4 (1.9%) | ||
No | 331 (97.4%) | 204 (98.1%) | ||
Family history | χ2 = 1.673 | 0.196 | ||
Yes | 8 (2.4%) | 9 (4.3%) | ||
No | 332 (97.6%) | 199 (95.7%) |