Table 1 Baseline characteristic of studies included in the systematic review and meta-analysis
Study | Country | Study design | Sample size | Cases | Age at baseline | Effect estimate | Follow-up (year) | Covariates in fully adjusted model | NOS score |
|---|---|---|---|---|---|---|---|---|---|
ET Chang 2007 [15] | US | Cohort | 90371 | 253 | 50.0 | RR | 8.1 | Race, total energy intake, parity, oral contraceptive use, strenuous exercise, and menopausal status/HRT use; stratified by age at baseline | 6 |
NE Allen 2009 [27] | UK | Cohort | 1280296 | 3559 | 55.9 | RR | 7.2 | Age, region of residence, socioeconomic status, BMI, smoking, physical activity, use of oral contraceptives, and HRT | 8 |
EV Bandera 1997 [28] | US | Cohort | 22550 | 77 | 50-93 | RR | 7.0 | Age, education, cigarettes/day, years smoking, and total energy intake | 7 |
ER Bertone 2002 (a) [29] | US | Cohort | 80195 | 120 | 34-59 | RR | 16.0 | Age, parity, age at menarche, menopausal status/postmenopausal HRT used, tubal ligation, and smoking status | 9 |
ER Bertone 2002 (b) [29] | US | Cohort | 59538 | 315 | 40-65 | RR | 16.0 | Age, parity, age at menarche, menopausal status/postmenopausal HRT used, tubal ligation, and smoking status | 9 |
EE Calle 2002 [30] | US | Cohort | 60796 | 278 | 50-74 | RR | 5.0 | Calendar year age at menarche, menopausal status at baseline, oral contraceptive use, HRT use among postmenopausal women, parity, BMI, smoking status, physical activity, and energy intake | 5 |
LE Kelemen 2004 [31] | US | Cohort | 27205 | 147 | 55-69 | RR | 15.0 | Age at menopause, physical activity, postmenopausal HRT, oral contraceptive use, family history of breast cancer, family history of ovarian cancer, known diabetes at baseline, smoking, energy-adjusted intakes of total carotene, vitamin C and vitamin E | 9 |
JV Lacey 2002 [14] | US | Cohort | 32885 | 142 | 40-93 | RR | 13.4 | Age, menopause type, and oral contraceptive use | 8 |
SC Larsson 2004 [32] | Sweden | Cohort | 61103 | 287 | 40-74 | RR | 10.5 | Age, BMI, educational level, family history of breast cancer, parity, age at first birth, oral contraceptive use, age at menarche, age at menopause, postmenopausal HRT, fruit and vegetable, lactose, and total energy intake. | 8 |
J Lin 2004 [33] | US | Cohort | 32466 | 104 | 45-89 | RR | 8.7 | Age, random treatment assignment, BMI, family history of colorectal cancer, history of colorectal polyps, physical activity, cigarette smoking, postmenopausal HRT, and total energy intake | 7 |
B Rockhill 1998 [34] | US | Cohort | 91502 | 52 | 27-44 | RR | 6.0 | Age at baseline, age at menarche, history of benign breast disease, history of breast cancer in mother and/or sister, height, oral contraceptive history, and parity and age at first birth | 6 |
LJ Schouten 2004 [35] | Netherland | Cohort | 62573 | 214 | 55-69 | RR | 9.3 | Age, use of oral contraceptives, parity, height, BMI, total energy intake, and current cigarette smoking | 8 |
PD Terry 2003 [36] | Canada | Cohort | 49613 | 223 | 40-59 | RR | 16.5 | Age in 5-year age groups, treatment allocation, study centre, Quetelet’s index, education level, vigorous physical activity, oral contraceptive use, HRT, parity, age of menarche, and menopausal status | 8 |
E Weiderpass 2012 [37] | Japan | Cohort | 45748 | 86 | 40-69 | HR | 16.0 | Age, study center, age at menarche, nulliparous, parity, age at first birth, breastfeeding, use of exogenous hormones, menopausal status, height, BMI, smoking status, exposure to second-hand smoke, physical activity, usual sleep duration, family history of cancer | 7 |