Table 2.

Age-adjusted and multivariable-adjusted hazard ratios and 95% confidence intervals for CHD by ABO blood type

Cohort	O	A	B	AB
NHS
No. of cases/No. of person-years	841/673089	723/564896	296/208358	195/120801
Age-adjusted HR (95% CI)	1.0	1.04(0.94-1.15)	1.14(1.00-1.30)	1.20(1.02-1.40)
Multivariate model 1 HR (95% CI)*	1.0	1.06(0.96-1.17)	1.15(1.00-1.31)	1.20(1.03-1.41)
Multivariate model 2 HR (95% CI)†	1.0	1.08(0.97-1.21)	1.15(0.99-1.33)	1.24(1.05-1.48)
HPFS
No. of cases/No. of person-years	833/223128	737/192687	246/63531	199/37966
Age-adjusted HR (95% CI)	1.0	1.07(0.96-1.18)	1.10(0.95-1.27)	1.26(1.07-1.48)
Multivariate model 1 HR (95% CI)*	1.0	1.08(0.97-1.19)	1.08(0.93-1.25)	1.18(1.00-1.39)
Multivariate model 2 HR (95% CI)†	1.0	1.08(0.97-1.19)	1.08(0.93-1.25)	1.17(1.00-1.38)
Combined
Age-adjusted HR (95% CI)	1.0	1.05(0.98-1.13)	1.11(1.01-1.23)	1.23(1.10-1.37)
Multivariate model 1 HR (95% CI)	1.0	1.07(0.99-1.15)	1.11(1.01-1.23)	1.19(1.06-1.33)
Multivariate model 2 HR (95% CI)	1.0	1.08(1.00-1.16)	1.11(1.00-1.24)	1.20(1.07-1.36)

CHD, coronary heart disease; CI, confidence interval; HPFS, Health Professionals Follow-up Study; HR, hazard ratios; NHS, Nurses’ Health Study.

^*adjusted for age (continuous), smoking (never, past, current with cigarette use of 1-14/day, 15-24/day, 25+/day, missing), BMI (< 23.0, 23.0-25.0, 25.0-29.0, ≥29.0), alcohol intake (0g/day, up to 5g/day, 5-15g/day, >15g/day), parental history of myocardial infarction before age 60 (yes/no), physical activity (MET h/wk in quintiles), aspirin use (<1/wk, 1-2/wk, 3-6/wk, 7-14/wk, 15+/wk), history of hypertension and high blood cholesterol and type 2 diabetes (yes or no), race/ethnicity (white or non-white), and menopausal status and postmenopausal hormone use (pre-menopausal, never, past, current hormone use) in women;

^†adjusted for covariates in model 1 plus dietary factors including multiple vitamin or vitamin E supplement (yes or no), total energy intake, polyunsaturated, saturated and trans fats, long-chain omega-3 fatty acids, dietary fiber, and folate intake (all in quintiles).