From: Population versus hospital controls for case-control studies on cancers in Chinese hospitals
Factor | Hospital controls (n = 540) | Population controls (n = 540) | P value a |
---|---|---|---|
Age (years) | 56.2 (10.6) | 56.2 (10.6) | |
Marital status | 0.64 | ||
Married | 499 (92.4) | 504 (93.3) | |
Others | 41 (7.6) | 36 (6.7) | |
Household size | 2.9 (1.1) | 3.0 (1.0) | 0.20 |
Education | 0.50 | ||
No or primary school | 46 (8.5) | 37 (6.9) | |
Junior high school | 208 (38.5) | 219 (40.6) | |
Senior high school | 119 (22.0) | 106 (19.6) | |
Tertiary education | 167 (30.9) | 178 (33.0) | |
Income (per capita, Yuan/month) | 0.50 | ||
≤ 1000 | 69 (12.8) | 80 (14.8) | |
1001-2000 | 347 (64.3) | 330 (61.1) | |
≥ 2001 | 124 (23.0) | 130 (24.1) | |
BMI (kg/m2) | 23.7 (3.1) | 24.0 (3.3) | 0.07 |
Smoking (≥ 20 packs in lifetime) | 98 (18.1) | 104 (19.3) | 0.70 |
Years of smoking | 5.2 (11.9) | 5.1 (11.4) | 0.86 |
Number of cigarettes per day | 3.2 (7.7) | 3.4 (8.2) | 0.59 |
Quitting smoking | 20 (3.7) | 12 (2.2) | 0.21 |
Alcohol consumption (ethanol g/day) | 6.6 (20.8) | 5.6 (16.0) | 0.39 |
Years of green tea drinking | 5.1 (9.7) | 5.5 (10.2) | 0.47 |
Dried green tea leaves (g/year) | 251.0 (539.7) | 282.1 (665.8) | 0.40 |
Physical activity (MET hrs/week) | 56.4 (49.0) | 53.9 (42.8) | 0.36 |
Malignancies in first degree relatives | 81 (15.0) | 90 (16.7) | 0.53 |