Table 1.
Baseline characteristics of the Shanghai Women’s (1997–2000) and Men’s (2002–2006) Health Studies, comparing liver cancer patients with study participants who did not develop liver cancer
| Characteristic* | Women | Men | ||||
| Participants who developed liver cancer (n=118) | Participants who did not develop liver cancer (n=72 368) | P† | Participants who developed liver cancer (n=149) | Participants who did not develop liver cancer (n=60 202) | P† | |
| Mean age at recruitment (SD), y | 59.0 (8.8) | 52.4 (9.0) | <.001 | 59.4 (10.1) | 55.2 (9.7) | <.001 |
| Mean body mass index (SE), kg/m2 | 24.7 (0.3) | 24.0 (0.0) | .03 | 23.3 (0.3) | 23.7 (0.0) | .10 |
| Mean total energy intake (SE), kcal/d | 1688.5 (32.1) | 1644.1 (1.3) | .17 | 1910.0 (38.7) | 1908.3 (1.9) | .97 |
| Mean fat intake (SE), g/d | 30.5 (1.0) | 29.6 (0.0) | .42 | 37.3 (1.3) | 34.5 (0.1) | .03 |
| Family income, per person per year, No. (%) | .62 | .003 | ||||
| Low | 44 (29.2) | 19 894 (27.5) | 103 (68.0) | 33 032 (54.9) | ||
| Middle | 48 (44.9) | 28 138 (38.9) | 37 (24.8) | 21 286 (35.4) | ||
| High | 26 (25.8) | 24 336 (33.6) | 9 (7.2) | 5884 (9.8) | ||
| Education level, No. (%) | <.001 | .01 | ||||
| Elementary school or less | 57 (29.4) | 15 278 (21.1) | 22 (9.5) | 4702 (7.8) | ||
| Middle school | 22 (29.2) | 27 015 (37.3) | 48 (31.9) | 19 892 (33.0) | ||
| High school | 34 (32.9) | 20 273 (28.0) | 57 (43.9) | 21 498 (35.7) | ||
| College or above | 5 (8.5) | 9802 (13.5) | 22 (14.7) | 14 110 (23.4) | ||
| Ever had viral hepatitis, No. (%) | 20 (27.1) | 1873 (2.6) | <.001 | 51 (40.3) | 4122 (6.8) | <.001 |
| Ever had chronic liver disease or cirrhosis, No. (%) | 5 (3.2) | 582 (0.8) | <.001 | 24 (16.6) | 1978 (3.3) | <.001 |
| Ever had diabetes, No. (%) | 12 (6.2) | 3047 (4.2) | .16 | 20 (8.7) | 3689 (6.1) | .01 |
| Ever had cholelithiasis or cholecystectomy, No. (%) | 28 (17.0) | 8180 (11.3) | .01 | 24 (13.7) | 4645 (7.7) | .004 |
| Family history of liver cancer in first-degree relatives, No. (%) | 12 (12.7) | 2366 (3.3) | <.001 | 16 (11.7) | 2133 (3.5) | <.001 |
| Ever smoker, No. (%) | 3 (3.5) | 1993 (2.8) | .34 | 99 (70.0) | 41 908 (69.6) | .69 |
| Ever alcohol drinker, No. (%) | 3 (1.9) | 1632 (2.3) | .98 | 47 (25.9) | 20 257 (33.6) | .72 |
*All variables were standardized to age distribution at baseline. SE = standard error.
†The general linear model was used to calculate P for continuous variables: age at recruitment, body mass index, total energy intake, fat intake. Cochran–Mantel–Haenszel statistics were used to calculate P for categorical variables: family income level (low income for <5000 yuan/year in the SWHS and <12 000 yuan/year in the SMHS; medium income for 5000 to <10 000 yuan/year in the SWHS and 12 000 to <24 000 yuan/year in the SMHS; and high income for >10 000 yuan/year in the SWHS and >24 000 yuan/year in the SMHS); education level (elementary school or less, middle school, high school, college or above); family history of liver cancer (yes or no); history of viral hepatitis (yes or no); history of chronic liver disease or cirrhosis (yes or no), history of diabetes (yes or no), and history of cholelithiasis or cholecystectomy (yes or no). All statistical tests were two-sided.