survcomp (version 1.22.0)

combine.test: Function to combine probabilities

Description

The function combines several p-value estimated from the same null hypothesis in different studies involving independent data.

Usage

combine.test(p, weight, method = c("fisher", "z.transform", "logit"), hetero = FALSE, na.rm = FALSE)

Arguments

p

vector of p-values

weight

vector of weights (e.g. sample size of each study)

method

fisher for the Fisher's combined probability test, z.transform for the Z-transformed test, logit for the weighted Z-method

hetero

TRUE is the heterogeneity should be taken into account, FALSE otherwise

na.rm

TRUE if the missing values should be removed from the data, FALSE otherwise

Value

p-value

Details

The p-values must be one-sided and computed from the same null hypothesis.

References

Whitlock, M. C. (2005) "Combining probability from independent tests: the weighted Z-method is superior to Fisher's approach", J. Evol. Biol., 18, pages 1368--1373.

See Also

test.hetero.test

Examples

p <- c(0.01, 0.13, 0.07, 0.2)
w <- c(100, 50, 200, 30)

#with equal weights
combine.test(p=p, method="z.transform")
#with p-values weighted by the sample size of the studies
combine.test(p=p, weight=w, method="z.transform")