meta.ave.stdmean2: Confidence interval for an average standardized mean...

In dgbonett/vcmeta: Varying Coefficient Meta-Analysis

Confidence interval for an average standardized mean difference from 2-group studies

Description

Computes the estimate, standard error, and confidence interval for an average standardized mean difference from two or more 2-group studies. Square root unweighted variances, square root weighted variances, and single group standard deviation are options for the standardizer. Equality of variances within or across studies is not assumed.

Usage

meta.ave.stdmean2(alpha, m1, m2, sd1, sd2, n1, n2, stdzr, bystudy = TRUE)

Arguments

alpha	alpha level for 1-alpha confidence
m1	vector of estimated means for group 1
m2	vector of estimated means for group 2
sd1	vector of estimated SDs for group 1
sd2	vector of estimated SDs for group 2
n1	vector of group 1 sample sizes
n2	vector of group 2 sample sizes
stdzr	set to 0 for square root unweighted average variance standardizer set to 1 for group 1 SD standardizer set to 2 for group 2 SD standardizer set to 3 for square root weighted average variance standardizer
bystudy	logical to also return each study estimate (TRUE) or not

Value

Returns a matrix. The first row is the average estimate across all studies. If bystudy is TRUE, there is 1 additional row for each study. The matrix has the following columns:

• Estimate - estimated effect size

• SE - standard error

• LL - lower limit of the confidence interval

• UL - upper limit of the confidence interval

References

\insertRef

Bonett2009avcmeta

Examples

m1 <- c(21.9, 23.1, 19.8)
m2 <- c(16.1, 17.4, 15.0)
sd1 <- c(3.82, 3.95, 3.67)
sd2 <- c(3.21, 3.30, 3.02)
n1 <- c(40, 30, 24)
n2 <- c(40, 28, 25)
meta.ave.stdmean2(.05, m1, m2, sd1, sd2, n1, n2, 0, bystudy = TRUE)

# Should return: 
#         Estimate        SE        LL       UL
# Average 1.526146 0.1734341 1.1862217 1.866071
# Study 1 1.643894 0.2629049 1.1286100 2.159178
# Study 2 1.566132 0.3056278 0.9671126 2.165152
# Study 3 1.428252 0.3289179 0.7835848 2.072919

dgbonett/vcmeta documentation built on July 12, 2024, 3:12 p.m.