FSA (version 0.8.8)

poiCI: Confidence interval for Poisson rate parameter.

Description

Computes a confidence interval for the Poisson mean rate parameter.

Usage

poiCI(x, conf.level = 0.95)

Arguments

x

A number representing the number of observed successes.

conf.level

A number that indicates the level of confidence to use for constructing confidence intervals (default is 0.95).

Value

A 1x2 matrix that contains the lower and upper confidence interval bounds.

Details

Computes a CI for the Poisson mean using the method described in Ulm (1990), though this method was earlier described by Liddell (1984) and possibly Garwood (1936) as noted in van der Gulden and Verbeck (1992). Thank you to Jerry Lewis for clarifications to the historical citations of this method.

References

Garwood, F. 1936. Fiducial limits for the Poisson distribution. Biometrika. 28(3/4):437-442.

Liddell, F.D. 1984. Simple exact analysis of the standardised mortality ratio. Journal of Epidemiology and Community Health. 38(1):85-88.

Ulm, K. 1990. A simple method to calculate the confidence interval of a standardized mortality ratio. American Journal of Epidemiology 131(2):373-375.

vand der Gulden, J.W.J. and A.L.M. Verbeck. 1992. Re: “A simple method to calculate the confidence interval of a standardized mortality ratio (SMR)”. American Journal of Epidemiology 136(9):1170-1171.

See Also

See pois.exact in epitools for similar functionality.

Examples

poiCI(12)