dsr: Calculate directly standardized rate

Description Usage Arguments Details Value References

View source: R/dsr.R

Description

Calculate a directly standardised rate with confidence interval based on a specified method.

Usage

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dsr(x, n, w, ci.method = c("asymptotic", "moments", "gamma", "beta",
  "bootstrap"), level = 0.95, mult = 1000, ...)

Arguments

x

a vector of strata-specific counts

n

a vector of strata-specific time bases for counts

w

a vector of strata-specific weights (or standard populations)

ci.method

method used to calculate the confidence interval. See details

level

the confidence level required

mult

a factor to multiply the estimate to give rates per mult

...

Further arguments passed to the confidence interval function.

Details

Five groupds of methods can be specified using 'ci.method', with variations on each depending on the method. five groups are:

'asymptotic' Using the normal approximation of the MLE distribution (or transformed MLE distribution). See ci.asymptotic for more details and the currently implemented transformations.
'moments' Moment matching based on Dobson et al (1991). A variety methods for constructing the confidence interval on the unweighted sum of x. - See ci.moments for more details.
'gamma' Based on the gamma distribution (Fay & Feuer 1997). See ci.gamma for more details and modifications implemented.
'beta' Based on the beta distribution as proposed by Tiwari et al (2006). See ci.beta for details and the modifications implemented.
'bootstrap' Appromiximate Bootstrap Confidence proposed by Swift (1995).

Value

dsr returns an object of class "dsr" . The function confint is used to return a confidence interval using a specified method

An object of class "dsr" is a list containing the following components:

estimate the estimate of the directly standardised rate
lower lower bound of the confidence interval
upper upper bound of the confidence interval
level the level of confidence
ci.method method used to calcalate the confidence interval
method.arg additional argument passed to ci method function
call the matched call
mult The multiplicative factor to scale the final estimate
strata number of strata or summands

References

Dobson, AJ, Kuulasmaa, K, Eberle, E and Scherer, J (1991) 'Confidence intervals for weighted sums of Poisson parameters', Statistics in Medicine, 10: 457–462. doi: 10.1002/sim.4780100317

Swift, MB (1995). 'Simple confidence intervals for standardized rates based on the approximate bootstrap method', Statistics in Medicine, 14, 1875–1888. doi: 10.1002/sim.4780141704.

Fay & Feuer (1997). 'Confidence intervals for directly standardized rates: a method based on the gamma distribution. Statistics in Medicine*. 16: 791–801. https://doi.org10.1002/(SICI)1097-0258(19970415)16:7<791::AID-SIM500>3.0.CO;2-%23

Tiwari, Clegg, & Zou (2006). 'Efficient interval estimation for age-adjusted cancer rates.' Statistical Methods in Medical Research 15: 547–569. doi: 10.1177/0962280206070621

Ng, Filardo, & Zheng (2008). 'Confidence interval estimating procedures for standardized incidence rates.' Computational Statistics and Data Analysis 52 3501-3516. doi: 10.1016/j.csda.2007.11.004


mnel/dsrci documentation built on May 22, 2017, 11:58 a.m.