Table 1. Baseline Characteristics of Included Studies, Copenhagen, Denmark, 1981-2001.

			Baseline cohorta		Year of questionnaire		Mean age, years (range)		Person-years of follow-up		BC events		High educational levelb
DCH			28 654		1993-97		56.2 (50-65)		347 320		1397		19.3%
CCHS II			2265		1981-83		55.7 (50-62)		47 327		190		7.6%
CRCPH
	Monica 1		840		1982-84		54.5 (50-60)		17 870		66		7.5%
	Monica 2		265		1986-87		55.5 (50-60)		5004		26		8.3%
	Monica 3		555		1991-92		59.8 (50-70)		8155		30		7.8%
	Inter99		983		1999-2001		52.8 (50-60)		8583		24		21.5%
Total			33 562		1981-2001		56.1		434 260		1733		18,0%

Abbreviations: BC events, breast cancer events; CCHS, Copenhagen City Heart Study (2^nd wave); CRCPH, The Cohorts at the Research

Centre for Prevention and Health; DCH, Diet, Cancer, and Health Study.

^a Sample size after exclusion of participants with baseline cancer and missing information on educational level, body mass index, alcohol consumption and parity.

^b ’High’ educational level defined as ≥ 15 years of education.