Table 3.

Age-adjusted and multivariable-adjusted hazard ratios and 95% confidence intervals for pancreatic cancer by ABO blood type^*

	ABO blood type
Cohort	O	A	AB	B
NHS
No. of cases/No. of person-years	70/289 174	71/238 774	22/53 134	36/90 750
Age-adjusted HR (95% CI)	1.00 (referent)	1.24 (0.89 to 1.72)	1.58 (0.98 to 2.55)	1.65 (1.11 to 2.47)
Multivariable-adjusted HR† (95% CI)	1.00 (referent)	1.25 (0.90 to 1.73)	1.57 (0.97 to 2.53)	1.65 (1.10 to 2.47)
HPFS
No. of cases/No. of person-years	39/110 109	47/95 073	11/19 362	20/31 619
Age-adjusted HR (95% CI)	1.00 (referent)	1.44 (0.94 to 2.21)	1.43 (0.73 to 2.79)	1.85 (1.08 to 3.18)
Multivariable-adjusted HR† (95% CI)	1.00 (referent)	1.45 (0.95 to 2.22)	1.40 (0.72 to 2.74)	1.84 (1.07 to 3.15)
Total study population
No. of cases/No. of person-years	109/399 283	118/333 847	33/72 496	56/122 369
Age-adjusted HR (95% CI)	1.00 (referent)	1.32 (1.01 to 1.71)	1.52 (1.03 to 2.24)	1.71 (1.24 to 2.36)
Multivariable-adjusted HR‡ (95% CI)	1.00 (referent)	1.32 (1.02 to 1.72)	1.51 (1.02 to 2.23)	1.72 (1.25 to 2.38)

^*NHS = Nurses’ Health Study; HR = hazard ratio; CI = confidence interval; HPFS = Health Professionals Follow-up Study; MET-h/wk = metabolic equivalent task hours per week.

^†Adjusted for age (years), body mass index (kg/m²), level of physical activity (MET-h/wk), smoking status (current, past, or never), and history of diabetes mellitus. NHS analysis also adjusted for history of pancreatic cancer in a participant's mother, father, or sibling.

^‡Adjusted for age (years), body mass index (kg/m²), level of physical activity (MET-h/wk), smoking status (current, past, or never), history of diabetes mellitus, and prospective cohort (NHS, HPFS, which also adjusts for sex).