prop_power {catfun}

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.

Details

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

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

See Also

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

Examples

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)