union.umbrella {metaumbrella}

Union of two objects of class “umbrella”

Description

Combine the factors included in two umbrella objects

Usage

union.umbrella(x, y, ...)

Arguments

x

an object of class “umbrella”.

y

an object of class “umbrella”.

...

other arguments that can be passed to the function

Details

This function allows to combine the results of two objects of class “umbrella”. This function is particularly useful when different specifications are used to analyze different factors. It is not possible to union two objects of class “umbrella” with different classifications.

Value

Return an object of class“umbrella”, with the factors of the two objects of class “umbrella”.

Examples

### union raw umbrella objects
umb1 <- umbrella(df.SMD, method.var = "REML")
umb2 <- umbrella(df.OR, method.var = "PM")
umb.union <- union.umbrella(umb1, umb2)
summary(add.evidence(umb.union, criteria = "GRADE"))

### union umbrella objects after applying stratification of evidence
umb1 <- add.evidence(umbrella(df.SMD), criteria = "GRADE")
umb2 <- add.evidence(umbrella(df.OR), criteria = "GRADE")
umb3 <- add.evidence(umbrella(df.IRR), criteria = "GRADE")
umb.union <- union.umbrella(union.umbrella(umb1, umb2), umb3)
summary(umb.union)