fmsb (version 0.5.2)

riskdifference: Calculate risk difference and its confidence intervals

Description

Calculate risk difference (a kind of attributable risk / excess risk) and its confidence intervals based on approximation, followed by null hypothesis (risk difference equals to 0) testing.

Usage

riskdifference(a, b, N1, N0, CRC=FALSE, conf.level=0.95)

Arguments

a

The number of disease occurence among exposed cohort.

b

The number of disease occurence among non-exposed cohort.

N1

The population at risk of the exposed cohort.

N0

The population at risk of the unexposed cohort.

CRC

Logical. If TRUE, calculate confidence intervals for each risk. Default is FALSE.

conf.level

Probability for confidence intervals. Default is 0.95.

Value

estimate

Calculated point estimate of risk difference.

conf.int

A numeric vector of length 2 to give upper/lower limit of confidence intervals.

p.value

The significant probability of the result of null-hypothesis testing.

References

Rothman KJ (2012) Epidemiology: An Introduction. 2nd Ed., Oxford University Press, Oxford.

Examples

 res <- riskdifference(321, 411, 686, 689, CRC=TRUE)
 str(res)
 print(res)