rate_ratio {popEpi}

Confidence intervals for the rate ratios

Description

Calculate rate ratio with confidence intervals for rate objects or observations and person-years.

Usage

rate_ratio(x, y, crude = FALSE, SE.method = TRUE)

Arguments

x

a rate-object, vector of two; rate and standard error or observed and person-years.

y

a rate-object, vector of two; rate and standard error or observed and person-years.

crude

set TRUE to use crude rates; default is FALSE.

SE.method

default TRUE; if x and y are vectors of observed and person-years, this must be changed to FALSE.

Details

Calculate rate ratio of two age standardized rate objects (see rate). Multiple rates for each objects is supported if there are an equal number of rates. Another option is to set x and y as a vector of two.

1. rate and its standard error, and set SE.method = TRUE.

2. observations and person-year, and set SE.method = FALSE.

See examples.

Value

A vector length of three: rate_ratio, and lower and upper confidence intervals.

Author(s)

Matti Rantanen

See Also

rate

Other rate functions: rate()

Examples

# two rate ratios; silly example with female rectal / breast cancer 
## mortality rates
data("sire", package = "popEpi")
data("sibr", package = "popEpi")

BL <- list(per = 2000:2005)

re <- lexpand(sire, birth = "bi_date", entry = "dg_date", exit = "ex_date",
              status = status == 1, breaks = BL, aggre = list(per))
br <- lexpand(sibr, birth = "bi_date", entry = "dg_date", exit = "ex_date",
              status = status == 1, breaks = BL, aggre = list(per))

r_re <- rate(re, obs = "from0to1", pyrs = "pyrs")
r_br <- rate(br, obs = "from0to1", pyrs = "pyrs")

rate_ratio(r_re, r_br, SE.method = TRUE)


# manually set rates (0.003 and 0.005) and SEs (0.001 and 0.002)
# so that x = y = c('rate', 'SE')
rate_ratio(x= c(0.003, 0.001), y= c(0.005, 0.002), SE.method = TRUE) 

# observed numbers (10 and 20) and person-years (30000 and 40000):
rate_ratio(x = c(10, 30000), y = c(20, 40000), SE.method = FALSE)