Table 4.

Estimates of colorectal cancer risk associated with metformin use after sulfonylurea use

Antidiabetic drug usePerson yearsNo. of eventsAdjusteda HR (95% CI)
Sulfonlyurea only80,847.121671.00 (reference)
Sulfonylurea+metformin58,725.951220.85 (0.65–1.12)
Duration metformin
 Never80,847.121671.00 (reference)
 <2.0 years25,050.73500.93 (0.67–1.29)
 2.0–4.9 years20,701.60440.88 (0.60–1.27)
 ≥5.0 years12,973.62280.62 (0.38–1.01)
Ptrend = 0.08