Table 4

Relation of cimetidine use to risk of prostate cancer among male users of H2 blockers in GHC, 1984–1996

Controls (N = 3920)Cases (N = 392)RR (95% CI)
N%N%
Ever used cimetidine
No70818.16817.41.0
Yes321281.932482.61.0 (0.8–1.4)
No. of prescriptions
Never used70818.16817.41.0
 155814.25514.01.0 (0.7–1.5)
 2–367317.25413.80.8 (0.6–1.2)
 4–1089922.99624.51.1 (0.8–1.5)
11–2054213.84812.20.9 (0.6–1.4)
21+54013.87118.11.4 (1.0–1.9)
Time since first eligible prescription
Never used70818.16817.41.0
<2 yr68117.45413.80.8 (0.5–1.2)
2 to <5 yr94824.210326.31.1 (0.8–1.6)
5 to <8 yr79020.28120.71.1 (0.8–1.5)
8+ yr79320.28621.91.1 (0.8–1.6)
Time since last prescription
Never used70818.16817.41.0
≤1 yr146137.315439.31.1 (0.8–1.5)
>1 yr to <2 yr40710.4369.20.9 (0.6–1.4)
2 to <5 yr74719.16917.61.0 (0.7–1.4)
5+ yr59715.26516.61.1 (0.8–1.6)