catfun (version 0.1.4)

prop_power: Power and sample size for 2 proportions

Description

Calculate power and sample size for comparison of 2 proportions for both balanced and unbalanced designs.

Usage

prop_power(n, n1, n2, p1, p2, fraction = 0.5, alpha = 0.05,
  power = NULL, alternative = c("two.sided", "one.sided"), odds.ratio,
  percent.reduction, ...)

Arguments

n

total sample size.

n1

sample size in group 1.

n2

sample size in group 2.

p1

group 1 proportion.

p2

group 2 proportion.

fraction

fraction of total observations that are in group 1.

alpha

significance level/type 1 error rate.

power

desired power, between 0 and 1.

alternative

alternative hypothesis, one- or two-sided test.

odds.ratio

odds ratio comparing p2 to p2.

percent.reduction

percent reduction of p1 to p2.

...

further arguments passed to or from other methods.

Value

a list with class "prop_power" containing the following components:

n

the total sample size

n1

the sample size in group 1

n2

the sample size in group 2

p1

the proportion in group 1

p2

the proportion in group 2

power

calculated or desired power

sig.level

level of significance

Details

Power calculations are done using the methods described in `stats::power.prop.test`, `Hmisc::bsamsize`, and `Hmisc::bpower`.

See Also

[stats::power.prop.test], [Hmisc::bsamsize], [Hmisc:bpower]

Examples

# NOT RUN {
prop_power(n = 220, p1 = 0.35, p2 = 0.2)
prop_power(p1 = 0.35, p2 = 0.2, fraction = 2/3, power = 0.85)
prop_power(p1 = 0.35, n = 220, percent.reduction = 42.857)
prop_power(p1 = 0.35, n = 220, odds.ratio = 0.4642857)

# }