compeir (version 1.0)

iprop: Event-specific incidence proportions

Description

This function computes event-specific incidence proportions using the competing events incidence rates. Also, corresponding variances and confidence intervals are provided.

Usage

iprop(irates, ci.fun = NULL, ci.level = NULL)

Arguments

irates

irates object

ci.fun

A character value out of c(“lin”, “score”) that specifies the confidence interval function, either linear or score. If NULL, ci.fun is set to “score”

ci.level

A numerical value between 0 and 1 that specifies the level for the two-sided confidence interval. If NULL, ci.level is inherited from irates

Value

An object of class iprop. This object is implemented as a list of the (besides pre-specified) following items:

ip

Competing events incidence proportions

var

Variance estimates for competing events incidence proportions

conf.lower

Lower confidence interval corresponding to pre-specified function and level

conf.upper

Upper confidence interval corresponding to pre-specified function and level

Details

The incidence proportion is defined as the number of new cases of disease in a sample divided by the sample without disease at baseline. It requires complete data. It is a non-parametric statistic, however, it does not account for time at risk.

References

Altman, D., Machin, D., Bryant, T., Gardner, S. (2000) Statistics with Confidence: Confidence intervals and statistical guidelines. Second edition. Bristol: BMJ Books.

See Also

print.iprop, irates, cif

Examples

### Example data.frame with aggregated count data
dat <- data.frame(
			times = c(7948,2899), 
			no.event = c(6,8), 
			event.1 = c(589,68), 
			event.2 = c(55,21), 
			row.names = c("covar0","covar1"))  

### Compute irates object from dat
ir <- irates(dat)

### Compute incidence proportions from irates object
iprop(ir)