RDmn1 {sasLM}

Risk Difference and Score CI between two groups without strata by the MN method

Description

Risk difference and its score confidence interval between two groups without stratification

Usage

  RDmn1(y1, n1, y2, n2, conf.level=0.95, eps=1e-8)

Arguments

y1

positive event count of test (the first) group

n1

total count of the test (the first) group. Maximum allowable value is 1e8.

y2

positive event count of control (the second) group

n2

total count of control (the second) group. Maximum allowable value is 1e8.

conf.level

confidence level

eps

absolute value less than eps is regarded as negligible

Details

It calculates risk difference and its score confidence interval between the two groups. The confidence interval is asymmetric, and there is no standard error in the output. If you need percent scale, multiply the output by 100. This does not support stratification. This implementation uses uniroot function which usually gives at least 5 significant digits.

Value

There is no standard error.

p1

proportion from the first group, y1/n1

p2

proportion from the second group, y2/n2

RD

risk difference, p1 - p2

lower

lower confidence limit of RD

upper

upper confidence limit of RD

Author(s)

Kyun-Seop Bae [e-mail]

References

Miettinen O, Nurminen M. Comparative analysis of two rates. Stat Med 1985;4:213-26

See Also

RRmn1, ORmn1, RDmn, RRmn, ORmn

Examples

  RDmn1(104, 11037, 189, 11034)