Table 1.

Baseline characteristics of studies included in meta-analysis

First author (year) (ref.)Country, study nameStudy participants & age rangeNo. of casesBMI determinationRecruitment period(FU) yearAdjustments
Nested case-cohorts
Bernstein et al. (1999) (23)USA, SEER 4 region database671 women with breast cancer Age range not stated324From medical records1978–1992 (not stated)Age, smoking, OC use, HRT use, tamoxifen & breast cancer chemotherapy
Schouten et al. (2004) (26)Netherlands, Netherlands Cohort Study1,636 55–69 y226Baseline questionnaire1986–1994 (9.3)Age, smoking, physical activity, age at menarche, OC use, parity, menopausal status
Twin Study
Lundqvist et al. (2007) (36)Sweden, Swedish Twin Registry14,058 43–89 y180Self administered questionnaire1961–1975 (22)Age, smoking, education, physical activity, birth country, diabetes
Cohorts
Baanders-van Halewijn et al. (1985) (20)The Netherlands, the DOM project14,000 50–65 y43Questionnaire1974–1980 (7.5)Age
Tornberg & Carstensen (1994) (21)Sweden, Two Countries Screening Programme47,003 Age range not stated412Weight & height “were measured”1963–1965 (20.3)Age, period of follow-up
Tulinius et al. (1997) (22)Iceland, Icelandic Cardiovascular Risk Factor Study11,580 Age range not stated98“Anthropometric measurements”1967–1969 (not stated)Age
Olson et al. (1999) (24)USA, Iowa Women Study24,848 55–69 y332Multi-phase questionnaire1986–1987 (10)Age
Furberg & Thune (2003) (25)Norway, Norwegian Cohort Study24,460 20–49 y130Weight & height “were measured”1974–1981 (15.7)Age, smoking, birthcountry, physical activity, hypertension & serum glucose
Kuriyama et al. (2005) (27)Japan, Miyagi Prefecture Study13,747 over 40 y22Self reported1984—1992 (9)Age, smoking, alcohol, dietary factors, parity, menopausal status, health insurance type
Lacey et al. (2005) (28)USA, Breast Cancer Detection Demonstration Project30,379 Age range not stated541Questionnaire1979–1998 (13)Age, HRT use, type of HRT
First author (year) (ref.)Country, study nameStudy participants & age rangeNo. of casesBMI determinationRecruitment period(FU) yearAdjustments
Rapp et al. (2005) (29)Austria, Vorarlberg Health Monitoring and the Promotion Program (VHM & PP) Study78,484 19–94 y175Weight & height “were measured by trained staff”1985–2001 (9.9)Age, smoking, occupational group
Silvera et al. (2005) (30)Canada, Canadian National Breast Screening Study49,613 40–59 y426Questionnaire1980–1985 (16.4)Age, smoking, alcohol, diet, physical activity, age at menarche, OC use, parity, menopausal status, HRT use
Bjorge et al. (2006) (31)Norway, Cancer Registry of Norway1,038,018 20–74 y9,227Weight & height “were measured by trained staff“1963–1965 (25)Age, birth cohort
Lukanova et al. (2006) (32)Sweden, Northern Sweden Health & Disease Cohort35,362 29–61 y118Weight & height “were measured”1985–1996 (8.3)Age, smoking, calendar year
Chang et al. (2007) (33)USA, NIH-AARP Diet and Health Study Cohort103,882 50–71 y677Questionnaire1995–1996 (4.6)Age, race, smoking, physical activity, diabetes, age at menarche, parity, OC use, HRT use, age at menopause
Friedenreich et al. (2007) (34)Europe, European Prospective Investigation into Cancer and Nutrition223,008 35–70 y567Measured anthropometric factors except centers in France and from the Oxford ‘health conscious’ cohort1992–2000 (6.4)Age, smoking, dietary factors, alcohol, physical exercise, birth country, education, OC use, menopausal status, HRT use
Larsson et al. (2007) (35)Sweden, Swedish Mammography Cohort61,226 49–83 y608Self administered questionnaire, including height & weight1987–1990 (15.6)Age
Reeves et al. (2007) (37)UK, Million Women Study1,222,630 50–64 y2,657Questionnaire1996–2001 (5.4)Age, smoking, alcohol, physical activity, parity, menopausal status, HRT, geographic region, socioeconomic status
First author (year) (ref.)Country, study nameStudy participants & age rangeNo. of casesBMI determinationRecruitment period(FU) yearAdjustments
Setiawan et al. (2007) (12)Multiethnic, Multiethnic Cohort Study49,933 Age range not stated321Questionnaire1993–1996 (7.3)Age, family history, smoking, parity, menopausal status, HRT use, birth country, OC use, diabetes
Lindemann et al. (2008) (38)Norway, HUNT I study36,761 20–101 y222Weight & height “were measured”1984–1986 (15.7)Age, diabetes, smoking, physical activity, hypertension, alcohol
McCullough et al. (2008) (39)USA, Cancer Prevention Study II Nutrition Cohort33,436 55–70 y318Questionnaire1992—1993 (8.9)Age, smoking, age at menarche, OC use, parity, physical activity, age at menopause, HRT use
Song et al. (2008) (40)Korea, Korean National Health and Nutrition Survey170,481 40–64 y112Weight & height “were measured using standardized stadiometers and scales”1994—2003 (8.75)Age, height, smoking, alcohol, physical exercise, salary level
Conroy et al. (2009) (41)USA, Women's Health Study32,642 ≥45 y264Self reported, questionnaire1992—1995 (8.8)Age, smoking, alcohol, saturated fat intake, fiber intake, fruit/vegetable intake, parity, menopausal status, HRT use, HRT type
Lindemann et al. (2009a) (42)Norway, HUNT II study31,473 20 yr and older100Weight & height “were measured”1995—1997 (9.0)Age, lipids, diabetes, hypertension, smoking, parity

BMI: body mass index. FU: follow-up. OC: oral contraceptive use. HRT: hormonal replacement therapy.