fmsb (version 0.5.2)

ratedifference: Calculate incidence rate difference and its confidence intervals

Description

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

Usage

ratedifference(a, b, PT1, PT0, 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.

PT1

The observed person-time of the exposed cohort.

PT0

The observed person-time of the unexposed cohort.

CRC

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

conf.level

Probability for confidence intervals. Default is 0.95.

Value

estimate

Calculated point estimate of incidence rate 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 <- ratedifference(136, 1709, 22050, 127650, CRC=TRUE)
 str(res)
 print(res)