epi.cluster1size {epiR}R Documentation

Sample size under under one-stage cluster sampling

Description

Estimates the required sample size under under one-stage cluster sampling.

Usage

epi.cluster1size(n, mean, var, epsilon, method = "mean", 
   conf.level = 0.95)

Arguments

n an integer representing the total number of clusters in the population.
mean a number representing the population mean of the variable of interest.
var a number representing the population variance of the variable of interest.
epsilon the maximum relative difference between our estimate and the unknown population value.
method a character string indicating the method to be used. Options are total, mean or mean.per.unit.
conf.level scalar, defining the level of confidence in the computed result.

Value

Returns an integer defining the size of the sample required.

References

Levy PS, Lemeshow S (1999). Sampling of Populations Methods and Applications. Wiley Series in Probability and Statistics, London, pp. 258.

Examples

## We intend to conduct a survey of residents to estimate the total number
## over 65 years of age that require the services of a nurse. There are 
## five housing complexes in the study area and we expect that there might
## be a total of around 34 residents meeting this criteria (variance 6.8).
## We would like the estimated sample size to provide us with an estimate
## that is within 10% of the true value. How many housing complexes should
## be sampled?

epi.cluster1size(n = 5, mean = 34, var = 6.8, epsilon = 0.10, method = 
   "total", conf.level = 0.999)

## We would need a simple one-stage cluster sample of 3 housing complexes to 
## meet the specifications for this study.


[Package epiR version 0.9-11 Index]