Estimate risk ratio and compute CI limits from two-by-two table

Given counts in a two-by-two table, computes risk ratio and confidence interval limits.

twoXtwoRR(n11, n10, n01, n00, alpha = 0.05)

Arguments

n11	Number exposed (X=1) and diseased (D=1)
n10	Number exposed (X=1) and not diseased (D=0)
n01	Number unexposed (X=0) and diseased (D=1)
n00	Number unexposed (X=0) and not diseased (D=0)
alpha	Alpha level associated with confidence interval

Examples

# Hammond and Holl (1958 JAMA) Data
# Two by Two Table
#          Lung Cancer    No Lung Cancer
# Smoker    397            78557
# Nonsmoker 51             108778

twoXtwoRR(397, 78557, 51, 108778)
#>     point     upper     lower 
#> 10.729780 14.359688  8.017457